Intermolecular hydroaminoalkylation of alkenes and dienes using a titanium mono(formamidinate) catalyst

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Intermolecular hydroaminoalkylation of alkenes

and dienes using a titanium mono(formamidinate)

catalyst†

Cite this: Dalton Trans., 2015, 44,

12149

Jaika Dörﬂer, Till Preuß, Christian Brahms, Dennis Scheuer and Sven Doye*

An easily accessible formamidinate ligand-bearing titanium complex initially synthesized by Eisen et al. is

used as catalyst for intermolecular hydroaminoalkylation reactions of unactivated, sterically demanding

1,1- and 1,2-disubstituted alkenes and styrenes with secondary amines. The corresponding reactions,

which have never been achieved with titanium catalysts before, take place with excellent regioselectivity

(up to 99 : 1) and in addition, corresponding reactions of 1,3-butadienes with N-methylbenzylamine are

also described for the ﬁrst time.

Received 18th December 2014,

Accepted 3rd February 2015

DOI: 10.1039/c4dt03916e

www.rsc.org/dalton

Introduction

The direct addition of α-C(sp³)–H bonds of primary or second-

ary amines across C–C double bonds, the so-called hydroami-

noalkylation of alkenes, represents a very promising and atom-

eﬃcient approach towards the synthesis of various nitrogen-

containing molecules.¹Due to the fact that the formed α-alky-

lated amines are of great importance in the agrochemical, fine

chemical and pharmaceutical industries²a plethora of suitable

hydroaminoalkylation catalysts has already been identified in

recent years.^3–7Although hydroaminoalkylation reactions can

be achieved in the presence of ruthenium,³iridium,⁴group

5 metal,⁵zirconium,⁶or titanium catalysts⁷a number of limit-

ations in scope still exists. For example, ruthenium and

iridium catalysts can only be used for hydroaminoalkylation

reactions of amine substrates bearing a directing 2-pyridinyl

substituent bound to the nitrogen atom of the amine.^3,4

Furthermore, zirconium complexes only catalyze intramolecu-

lar hydroaminoalkylation reactions of primary aminoalkenes.⁶

On the other hand, group 5 metal⁵and titanium catalysts⁷

have successfully been applied for the intermolecular hydro-

aminoalkylation of alkenes, styrenes and 1,3-butadienes. For

example, the conversion of styrene (1) into the corresponding

hydroaminoalkylation products 3a and 3b (Scheme 1) could be

achieved in the presence of tantalum or titanium cata-

lysts.^5m,7d,g,i

Scheme 1 Intermolecular hydroaminoalkylation of styrene (1) with

N-methylaniline (2) catalyzed by group 4 and group 5 metal catalysts.

be controlled by the nature of the catalyst. Whereas in the pres-

ence of Ta(NMe₂)₅, the branched product 3a is formed almost

exclusively,^5mthe aminopyridinato titanium catalysts 4 and 5

favor the formation of the corresponding linear hydroami-

noalkylation product 3b.^7g,iHowever, so far, the use of tita-

nium catalysts is limited to hydroaminoalkylation reactions of

sterically less demanding mono-substituted alkenes, styrenes,

or 1,3-butadienes with N-alkylanilines or dialkylamines.

Among the class of sterically more demanding disubstituted

alkenes, only norbornene^7b–d,gand methylenecyclohexane^7c,g

were found to undergo hydroaminoalkylation reactions in the

In this context, it is worth mentioning that the regioselectiv-

ity of hydroaminoalkylation reactions of styrenes can simply

Institut für Chemie, Universität Oldenburg, Carl-von-Ossietzky-Strasse 9-11, D-26111

Oldenburg, Germany. E-mail: doye@uni-oldenburg.de

†Electronic supplementary information (ESI) available: Copies of the ¹H and ¹³

C

NMR spectra of all products. See DOI: 10.1039/c4dt03916e

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presence of selected titanium catalysts. On the other hand,

hydroaminoalkylation reactions of sterically demanding 1,1-

and 1,2-disubstituted alkenes are well known for group

5 metal catalysts.^{5c,e–g,i,k,l,n}Most impressively, very recently,

Schafer et al. reported a 2-pyridonate tantalum catalyst that is

able to catalyze high-yielding hydroaminoalkylation reactions

of sterically demanding E- and Z-internal alkenes like cyclohex-

ene, (E)- and (Z)-3-hexene, (Z)-β-methylstyrene or (E)-1-(para-

methoxyphenyl)propene.⁵ⁿIn the latter two cases, hydroami-

noalkylation at the β-carbon of the β-substituted styrene deriva-

tives is favored but only modest regioselectivities (up to 4.4 : 1)

could be achieved.

The mechanism of group 4 and 5 metal-catalyzed hydro-

aminoalkylation reactions has already been studied^{1,5c,d,i,6,7e}

and it is generally accepted that the amine substrate undergoes

N–H and C–H bond activation in the presence of the catalyst

precursor to give a strained metallaaziridine as the catalytically

active species. Subsequent alkene insertion into the M–C bond

of the metallaaziridine which determines the regioselectivity of

the over-all transformation then results in the formation of a

2-metallapyrrolidine. Finally, aminolysis of the M–C bond of the

five membered intermediate and product-forming C–H bond

activation regenerate the catalytically active metallaaziridine.

Herein, we present the first example of a titanium-based

catalyst for intermolecular hydroaminoalkylation reactions of

unactivated, sterically demanding 1,1- and 1,2-disubstituted

alkenes and styrenes with secondary amines. The corres-

ponding reactions take place with excellent regioselectivity (up

to 99 : 1) and the formamidinate ligand-bearing catalyst is also

capable of catalyzing reactions of 1,3-butadienes with

N-methylbenzylamine.

Scheme 2 Intermolecular hydroaminoalkylation of styrene (1) with

N-methylaniline (2) catalyzed by titanium mono(formamidinate)

complex 6.

(10 mol% 6, n-hexane, 140 °C, 96 h, sealed Schlenk tube),^7g,ithe

reaction took place smoothly to give a mixture of the two regio-

isomeric hydroaminoalkylation products 3a and 3b in an excel-

lent total yield of 96%. Unfortunately, the regioselectivity of the

reaction which in this case, favors the formation of the

branched product 3a was only modest (3a/3b = 73 : 27).

However, an interesting finding is the fact that in comparison

to the structurally related aminopyridinato catalysts 4 and 5, the

regioselectivity is reversed with the formamidinate catalyst 6.

Impressed by the high catalytic activity of complex 6 and

the clean formation of the desired hydroaminoalkylation pro-

ducts 3a and 3b, we further investigated whether complex 6 is

also able to catalyze intermolecular hydroaminoalkylation

reactions of sterically more demanding disubstituted alkenes

with N-methylaniline (2, Table 1).

As can be seen from Table 1, a number of successful hydro-

aminoalkylation reactions of 1,1- and 1,2-disubstituted alkenes

and styrenes with N-methylaniline (2) can be achieved at elev-

ated temperatures (140–180 °C) in the presence of 10 mol% of

catalyst 6. For example, methylenecyclohexane (7, Table 1,

entries 1 and 2) regioselectively reacted to the corresponding

branched amine 21a which could be isolated in excellent yield

of 90%. Even though bulky 1,1-diphenylethylene (8) did not

react at all under the applied conditions (Table 1, entries 3

and 4), α-methylstyrene (9) and para-α-dimethylstyrene (10)

could be converted regioselectively to the corresponding

branched hydroaminoalkylation products 22a and 23a,

respectively (Table 1, entries 5–8). In these cases, the yields of

the reactions were significantly improved by increasing the

reaction temperature from 140 °C to 180 °C. Finally, it was

possible to isolate the branched products 22a and 23a in 86%

and 91% yield, respectively. Although a corresponding depen-

dence on the reaction temperature had not been observed

during the initially performed reactions of methylenecyclohex-

ane (7, Table 1, entries 1 and 2) we performed most additional

reactions presented in Table 1 at 180 °C. A similar observation

was made when reactions of 7 or 9 were conducted with

reduced reaction times of 24 h or 48 h. While the reduced reac-

Results and discussion

In order to develop a more eﬃcient catalyst system that is able

to expand the substrate scope of the titanium-catalyzed inter-

molecular hydroaminoalkylation of alkenes, we recently

focused on ligand motifs which are structurally similar to the

aminopyridinato ligands of the second-generation hydroamino-

alkylation catalysts 4 and 5 (Scheme 1). In this context, it must

be mentioned that the chelating heteroallylic N–C–N unit of

the aminopyridinato ligands that binds to the titanium center

can also be found in the well-known class of amidinate ligands

[R¹-C(NR²)₂]⁻. A variety of corresponding group 4 amidinate

complexes has already been used as catalysts in the polymeriz-

ation of olefins by Eisen et al.⁸and a particular advantage of

this class of catalysts is that the ligands are easily prepared

and modified.^8aOn the other hand, corresponding catalysts

have never been used for hydroaminoalkylation reactions of

alkenes.

During an investigation of various titanium formamidinate

catalysts we found that complex 6 (Scheme 2) which bears 2,6-

diisopropylphenyl groups as the amidinate N-substituents^8ais

a highly active catalyst for the hydroaminoalkylation of styrene

(1) with N-methylaniline (2). Under usually applied conditions

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Table 1 Hydroaminoalkylation of disubstituted alkenes with N-methylaniline (2)

Entry

1

Alkene

T (°C)

Isolated product(s)

Yield^a(%)

90

Selectivity a/b^b

140

99 : 1

2

3

180

140

90^c

—

99 : 1

—

4

5

180

140

—

43

—

99 : 1

6

7

180

140

86^d

38

99 : 1

8

9

180

140

91

17

99 : 1

1 : 99

10

11

180

64

1 : 99

34 : 66

97^e

12

13

14

180

—

15

16

180

—

16^e

35 : 65

17

180

75

—

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Table 1 (Contd.)

Entry

18

Alkene

T (°C)

Isolated product(s)

Yield^a(%)

72^f

Selectivity a/b^b

180

—

19

180

93

—

^aReaction conditions: N-methylaniline (2, 2.0 mmol, 214 mg), alkene (3.0 mmol), 6 (109 mg, 0.2 mmol, 10 mol%), n-hexane (1 mL), 140 °C or

180 °C, 96 h, sealed Schlenk tube. Yields refer to the yield of the isolated product (a or b). ^bGC analysis prior to chromatography. ^cA yield of 89%

was obtained after a reaction time of 24 h. ^dYields of 76% and 67% were obtained after reaction times of 48 h and 24 h, respectively. ^eThe yield

refers to the total yield of isolated products (a + b). ^fA comparable yield of 69% was obtained after a reaction time of 192 h.

tion times did not aﬀect the conversion of methylenecyclohex- styrene (11) to allylbenzene during the reactions of 11 could

ane (7, 89% yield of product 21a after 24 h), corresponding not be observed by GC analysis. Additional experiments with

reactions of α-methylstyrene (9) gave product 22a in signifi- indene (12, Table 1, entry 11) then revealed that even this chal-

cantly reduced yields (76% after 48 h and 67% after 24 h). As a lenging substrate undergoes successful hydroaminoalkylation

consequence, we performed all additional experiments with a with 2. Although the reaction delivered the two regioisomers

reaction time of 96 h. To the best of our knowledge, the results 25a and 25b in 97% combined yield, the regioselectivity was

obtained with styrenes 9 and 10 represent the first successful found to be surprisingly low (25a/25b = 34 : 66). However, as

examples of group 4 metal-catalyzed hydroaminoalkylation can be seen from Table 1, entries 12–15, sterically more

reactions of α-substituted styrene derivatives. In addition, it is demanding internal alkenes like 13–16 failed to react in the

worth to mention that only two examples of a corresponding presence of catalyst 6. On the other hand, it was possible to

reaction catalyzed by a group 5 metal catalyst have been convert (E)-2-octene (17) to a mixture of the corresponding

described in the literature^5k,mand in this case, the yield was hydroaminoalkylation products 26a and 26b (Table 1, entry 16)

only modest (61%). An additional finding that underlines the but in this case, the yield and the regioselectivity of the reac-

high catalytic activity of 6 is the fact that with this catalyst, it tion turned out to be poor. In contrast to the disappointing be-

was even possible to react the 1,2-disubstituted substrate (E)- havior of the 1,2-dialkyl-substituted (E)-alkenes 15–17, the (Z)-

β-methylstyrene (11) with N-methylaniline (2, Table 1, entries 9 double bond-containing substrates cyclopentene (18) and

and 10). Interestingly and in contrast to the reaction of cyclohexene (19) gave access to the corresponding hydroami-

α-methylstyrene, the hydroaminoalkylation took place regio- noalkylation products 27 and 28 in reasonable yields of 75%

selectively at the sterically less shielded β-carbon of the double and 72%, respectively (Table 1, entries 17 and 18). In this

bond and correspondingly, the regioisomer 24b could be iso- context, it can be noted that additional alkyl-substituted cyclo-

lated as the sole product of the reaction in 64% yield. Most hexenes like 4-methyl- or 3-methylcyclohexene also underwent

impressively, the regioselectivity of the reaction was found to high-yielding hydroaminoalkylation reactions with

2 but

be 24a/24b = 1 : 99. Previously, only two successful hydroami- unfortunately, formation of four inseparable regio- and dia-

noalkylations of β-substituted styrene derivatives had been stereomers was observed in both reactions. As the result, all

achieved with a tantalum catalyst⁵ⁿand in these cases, the attempts on a precise structure assignment of the isomers

regioselectivities were only modest (1 : 2.0 and 1 : 4.4). The failed so far. With regard to catalyst stability it can be stated

well-established fact that hydroaminoalkylation product 24b that longer reaction times do not necessarily lead to improved

can be obtained from allylbenzene under much milder condi- yields. For example, reactions of cylohexene (19) with N-methyl-

tions^5eis strongly underlined by a hydroaminoalkylation reac- aniline (2) gave comparable yields of product 28 after 96 h

tion between allylbenzene and N-methylaniline (2) performed (72%, Table 1, entry 18) and 192 h (69%). Interestingly, the

at 140 °C in the presence of 10 mol% of catalyst 6. While additional double bond present in 1,4-cyclohexadiene (20)

under these conditions, (E)-β-methylstyrene (11) gave 24b only seems to facilitate the hydroaminoalkylation reaction and as a

in 17% yield (Table 1, entry 9), 24b was obtained in 87% yield consequence, an excellent yield of 93% of product 29 was

from allylbenzene. Interestingly, isomerization of (E)-β-methyl- obtained in this case (Table 1, entry 19). The remarkable fact

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1,2,3,4-tetrahydroquinoline, and ortho-methyl-N-methylaniline

failed to react with α-methylstyrene (9) in the presence of cata-

lyst 6. On the other hand, the dialkylamines N-methylcylohexyl-

amine (36) and N-methylhexylamine (37) (Table 2, entries 5

and 6) were found to undergo highly regioselective hydroami-

noalkylation with 9 under identical reaction conditions. Unfor-

tunately, the branched products which were always formed

with excellent regioselectivity (a/b = 99 : 1) could only be

obtained in modest to poor yields (14–49%) after derivatization

as the corresponding para-toluenesulfonamides 42a and 43a.

Scheme 3 Intermolecular reaction of 3-methoxycyclohexene (30) with

N-methylaniline (2) catalyzed by titanium mono(formamidinate)

complex 6.

that only the monoalkylated product 29 could be isolated from The observation that both reactions took place at the methyl

the reaction mixture is in good agreement with results from group of the amines exclusively is in good agreement with

Schafer et al.⁵ⁿand the remaining double bond oﬀers a prom- results obtained before with N-methylcylohexylamine (36) and

ising chance for further functionalization. Finally, 3-bromo- N-methylhexylamine (37).^{5e,j,k,n,7f,g,i}Finally, it must be noted

cyclohexene turned out to be unreactive under the reaction that no successful alkylation of N-methylbenzylamine (38,

conditions while 3-methoxycyclohexene (30) underwent

a

Table 2, entry 7) could be achieved with α-methylstyrene (9).

nucleophilic substitution reaction that delivered the tertiary Additional hydroaminoalkylation reactions performed with

amine 31 in 61% yield (Scheme 3). The assumption that the (E)-β-methylstyrene (11, Table 2, entries 8–14) then revealed

latter process does not require the presence of a titanium cata- that 11 is significantly less reactive than α-methylstyrene (9)

lyst is strongly supported by the fact that product 31 could also and as a result, the corresponding hydroaminoalkylation pro-

be isolated in comparable yield (58%) from a control experi- ducts could only be obtained in modest to poor yields

ment performed in the absence of 6.

(14–65%). However, the trend in reactivity observed with the

Encouraged by the promising results obtained with N-methylanilines 32–34 (Table 2, entries 8–10) is in good

N-methylaniline (2) we next turned our attention towards agreement with the results obtained with α-methylstyrene (9,

hydroaminoalkylation reactions of α- and (E)-β-methylstyrene Table 2, entries 1–3). Again, the para-fluoro-substituted aniline

with various other secondary amines (Table 2). The unsymme- 33 gave the best result (65% yield) while the electron-donating

trically substituted styrenes were chosen as substrates to get para-phenoxy substituent present in 34 caused a severe drop in

further information about the regioselectivity of the hydroami- yield (14%). Among the dialkylamines 36–38 (Table 2, entries

noalkylation. Initial reactions of α-methylstyrene (9) with the 12–14), again only N-methylcylohexylamine (36) and N-methyl-

donor- and acceptor-substituted N-methylanilines 32–34 hexylamine (37) reacted successfully with 11 and in these

(Table 2, entries 1–3) performed at 180 °C in the presence of cases, the products could be isolated after derivatization as the

10 mol% 6 showed that both classes of substituents are gener- corresponding para-toluenesulfonamides 47b and 48b in 38%

ally tolerated and the para-substituents do not aﬀect the and 41% yield, respectively. On the other hand, no reaction

regioselectivity of the hydroaminoalkylation. In all cases, could be achieved with N-methylbenzylamine (38) and the

the regioselectivity was determined to be 99 : 1 in favor of the sterically more demanding substrate N-benzylaniline (35,

branched product a which is formed by hydroaminoalkylation Table 2, entries 11 and 14). However, as described above

at the sterically more hindered α-carbon of 9. On the other (Table 1, entry 9), all successful hydroaminoalkylation reac-

hand, the nature of the substituent on the benzene ring of the tions of (E)-β-methylstyrene (11) took place with excellent regio-

N-methylaniline seems to influence the eﬃciency of the reac- selectivities (≥98 : 2) at the sterically less hindered β-carbon of

tion significantly. For example, N-methylaniline 33 bearing an 11 giving access to 3-phenylpropylamine derivatives.

electron-withdrawing para-fluoro substituent on the benzene

Owing to the electronic similarities between styrenes and

ring gave the hydroaminoalkylation product 40a in 98% yield conjugated dienes, we next turned our attention towards

(Table 2, entry 2) while the corresponding donor-substituted hydroaminoalkylation reactions of substituted 1,3-butadienes.

substrate para-phenoxy-N-methylaniline (34) delivered the Corresponding reactions are extremely rare in the literature^4,7h,i

corresponding product 41a only in significantly reduced yield and so far, Ind₂TiMe₂(Ind = η⁵-indenyl)^7hand aminopyridi-

of 67% (Table 2, entry 3). This trend in reactivity is further sup- nato titanium complex 5⁷ⁱrepresent the only suitable early

ported by the observation that para-methyl-N-methylaniline transition metal catalysts for the intermolecular hydroamino-

(32) with its weak electron-donating methyl substituent gave alkylation of 1-aryl- and 1-alkyl-substituted 1,3-butadienes.

the hydroaminoalkylation product 39a in 88% yield (Table 2, Unfortunately, the titanium-catalyzed reaction is limited to

entry 1) which is comparable to the result obtained with selected N-methylanilines and the eﬃciency of the reaction

N-methylaniline (2, 86%, Table 1, entry 6). The well-established strongly depends on the substituents bound to the 1,3-diene

fact that the eﬃciency of titanium-catalyzed hydroaminoalkyla- or the benzene ring of the N-methylaniline. For example, reac-

tion reactions of alkenes is strongly influenced by the steric tions performed with the chloro-substituted substrates para-

bulk of the amine^7b,d,iis in good agreement with our obser- chloro-N-methylaniline or (E)-1-(para-chlorophenyl)-1,3-buta-

vation that the sterically more demanding amines N-benzylani- diene gave the corresponding hydroaminoalkylation products

line (35, Table 2, entry 4), N-ethylaniline, N-propylaniline, only in poor yields (≤37%) and in addition, dialkylamines or

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Table 2 Hydroaminoalkylation of α- and (E)-β-methylstyrene (9, 11) with various amines

Entry

1

Styrene

Amine

Isolated product

Yield^a(%)

88

Selectivity a/b^b

99 : 1

2

3

98

67

99 : 1

4

5

—

14^c,d

99 : 1

6

49^c,d

99 : 1

7

8

—

31

1 : 99

9

65

14

2 : 98

1 : 99

10

11

12

—

38^c,d

1 : 99

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Table 2 (Contd.)

Entry

13

Styrene

Amine

Isolated product

Yield^a(%)

41^c,d

Selectivity a/b^b

1 : 99

14

—

^aReaction conditions: amine (2.0 mmol), alkene (3.0 mmol), 6 (109 mg, 0.2 mmol, 10 mol%), n-hexane (1 mL), 180 °C, 96 h, sealed Schlenk tube.

Yields refer to the yield of the isolated product (a or b). ^bGC analysis prior to chromatography. ^cThe product was isolated after derivatization as

the corresponding para-toluenesulfonamide. ^dThe reaction took place at the methyl group of the amine exclusively.

N-alkylanilines bearing alkyl groups larger than a methyl tor-substituted N-methylanilines (59) and in all cases, only the

group did not react at all in the presence of Ind₂TiMe₂. Initial terminal double bond of the diene reacted. Owing to their

hydroaminoalkylation reactions of (E)-1-phenyl-1,3-butadiene better separation from other nitrogen-containing molecules in

(49) with various para-substituted N-methylanilines were per- the reaction mixture, the hydroaminoalkylation products were

formed in the presence of 10 mol% 6 at 120 °C. The relatively isolated after conversion into their corresponding acetamides

low reaction temperature was chosen because it has already (AcCl, NEt₃, CH₂Cl₂, rt). Although the products 60–66a/b could

been observed that dimerization of the 1,3-butadiene by Diels– be obtained with good to modest yields (45–82%), the regio-

Alder cycloaddition becomes a yield-reducing side reaction at selectivity of the hydroaminoalkylation was always close to 1 : 1

temperatures above 130 °C.^7hAs can be seen from Table 3, which is worse compared to typical regioselectivities obtained

entries 1–7, successful hydroaminoalkylation could be with the catalysts 5 or Ind₂TiMe₂. With the latter catalyst, for-

achieved with electron donor- (34, 55–58) and electron accep- mation of the branched regioisomer was usually favored and

Table 3 Hydroaminoalkylation of 1,3-dienes with N-methylanilines

Entry

Diene

R¹

R²

Amine

R³

Products

Yield^a(%)

Selectivity a/b^b

1

2

3

4

5

6

7

8

49

50

51

52

53

54

Ph

H

CH₃

2

H

60a/b

61a/b

62a/b

63a/b

64a/b

65a/b

66a/b

67a/b

68a/b

69a/b

70a/b^e

71a/b

73

45

46

82

53

64

65

52

53

68^c

87^e

73

55 : 45

54 : 46

53 : 47

54 : 46

53 : 47

50 : 50

34

55

56

57

58

59

2

p-OPh

p-OMe

p-OCF₃

p-SMe

p-iso-Pr

p-Cl

H

p-Cl-C₆H₄

p-F-C₆H₄

n-C₆H₁₃

C₆H₅-(CH₂)₂

Ph

9

50 : 50

10

11

12

50 : 27 : 23^d

47 : 28 : 25^d

51 : 49

^aReaction conditions: (1) amine (2.0 mmol), diene (3.0 mmol), 6 (109 mg, 0.2 mmol, 10 mol%), n-hexane (1 mL), 120 °C, 48 h, sealed Schlenk

tube; (2) acetyl chloride (1 M in CH₂Cl₂, 4.0 mmol), NEt₃(4.0 mmol), CH₂Cl₂(30 mL), 25 °C, 16 h. Yields refer to the total yield of isolated

products (a + b). ^bGC analysis prior to acetylation and chromatography. ^cThe reaction was carried out on a 4 mmol scale. ^dFormation of an

additional branched product with an isomerized double bond was observed. The selectivity is given as branched (a)/branched isomerized/linear

(b). For details, see the experimental section. ^eDirectly isolated as the corresponding amine (without acetylation).

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selectivities between 2 : 1 and 3 : 1^7hcould be achieved while 5 performed with 10 mol% 6 in n-hexane at 120 °C in sealed

produced linear regioisomers almost exclusively.⁷ⁱIn this Schlenk tubes and after 48 h, the reaction mixtures were ana-

context, it should be noted that separation of the regioisomers lyzed by GC. During this study, it was found that among the

is possible by chromatography. On the other hand, it is worth four amines, only N-methylbenzylamine (38) underwent suc-

mentioning that with several substrates significantly improved cessful hydroaminoalkylation with 49 in the presence of cata-

yields were obtained with the new catalyst 6. For example, lyst 6 (Table 4, entry 1). Interestingly and in good agreement

para-chloro-N-methylaniline (59) gave a mixture of the corres- with the behavior of aminopyridinato catalyst 4, a high regios-

ponding products 66a and 66b in 65% combined yield electivity of 93 : 7 in favor of the linear hydroaminoalkylation

(Table 3, entry 7) while the corresponding reaction performed product was observed and after conversion into the corres-

with Ind₂TiMe₂gave the same products only in 6% yield.^7hIn ponding para-toluenesulfonamide and purification by chrom-

addition, a significantly improved yield (46% versus 23%^7h

)

atography, the linear product 76b was isolated in 58% yield.

was obtained with para-methoxy-N-methylaniline (55) and it Due to the high regioselectivity of the reaction, the branched

was also possible to perform the hydroaminoalkylation with product could not be isolated but the NMR spectra of 76b

para-trifluoromethoxy-N-methylaniline (56, Table 3, entry 4). showed very weak signal sets, which could be assigned to trace

Amine 56 represents a highly promising substrate because the impurities of the branched product. In this context, it must

para-trifluoromethoxy group is often present in synthetic agro- also be mentioned that the isolated material additionally con-

chemicals and pharmaceuticals.⁹Impressively, even para-thio- tained minor amounts of tosylated N-methylbenzylamine

methyl-N-methylaniline (57) which does not undergo formed from unreacted amine 38. Interestingly and in contrast

hydroaminoalkylation with 49 in the presence of Ind₂TiMe₂to the reactions of N-methylcylohexylamine (36) and N-methyl-

did react in the presence of catalyst 6 (Table 3, entry 5). hexylamine (37) with α- and (E)-β-methylstyrene (9 and 11,

Additional reactions between N-methylaniline (2) and 1,3-buta- Table 2, entries 5, 6, 12 and 13), alkylation of 38 occurred at

dienes 50–54 (Table 3, entries 8–12) delivered mixtures of the the benzyl position of the amine exclusively. However, this

branched and the linear hydroaminoalkylation products observation is in good agreement with the fact that group 4^7g,i

67–71a/b in good to modest yields but again, only with poor and 5^5emetal-catalyzed hydroaminoalkylation reactions of

regioselectivities. In this context, it must be mentioned that a sterically less demanding mono-substituted alkenes and sty-

third product was formed during reactions of the 1-alkyl-sub- renes performed with 38 usually take place selectively at the

stituted dienes (E)-1,3-decadiene (52) and (E)-6-phenyl-1,3-hexa- benzyl position of 38. Selective alkylation at the methyl group

diene (53, Table 3, entries 10 and 11). These additionally of N-methylbenzylamine (38) has only been achieved with

formed products were identified to be branched hydroami- vinylcyclohexane in the presence of tantalum and niobium

noalkylation products with an isomerized double bond. The binaphtholate catalysts developed by the Hultzsch group.^5h,i

formation of two branched isomeric olefins from 2 and 52 was With these results in hand, we finally used the para-substi-

confirmed by hydrogenation of a mixture of 69a and its isomer tuted 1-phenyl-1,3-butadienes 50, 51, and 73 as well as the

with Pd/C which gave the corresponding saturated compound ortho-substituted dienes 74 and 75 for hydroaminoalkylation

N-phenyl-N-(2-methyldecyl)acetamide (72) as the sole hydro- reactions with amine 38 (Table 4, entries 2–6). The results

genation product in 85% yield. On the other hand, formation obtained with these substrates clearly prove that electron-with-

of additional linear hydroaminoalkylation products with iso- drawing chloro or fluoro substituents (Table 4, entries 2 and 3)

merized double bond was not observed in the presence of cata- and electron-donating methyl or methoxy groups (Table 4,

lyst 6. This is in sharp contrast to the finding that linear entries 4–6) as well as ortho-substitution of the phenyl ring

products with isomerized double bond are formed during (Table 4, entries 5 and 6) are tolerated with no significant

hydroaminoalkylation reactions of 1,3-butadienes catalyzed by impact on the yield (60–71%) and the regioselectivity

aminopyridinato titanium catalyst 5.⁷ⁱFinally, it was found (13 : 87–8 : 92) of the reaction. The latter finding is in good

that even the 1,2-disubstituted 1,3-diene 54 undergoes success- agreement with the remote position of the phenyl substituent

ful hydroaminoalkylation with 2. The corresponding products relative to the reacting double bond of the diene.^7hHowever,

71a and 71b were obtained in 73% combined yield and the in all cases, again only the linear hydroaminoalkylation pro-

regioselectivity was determined to be 51 : 49 (Table 3, entry 12). ducts 77–81b could be isolated from the reaction mixtures and

In this context, it is worth mentioning that 54 and 2 are exclu- the branched products were only detected by GC or as trace

sively converted into the branched hydroaminoalkylation impurities in the NMR spectra of the isolated linear products.

product with the catalyst Ind₂TiMe₂.

In this context, it is worth mentioning that corresponding

Because hydroaminoalkylation reactions of styrenes with δ-alkenylamine derivatives are promising substrates for the

N-alkylanilines catalyzed by aminopyridinato complex 4 have synthesis of cis-N-methyl-2,5-disubstituted pyrrolidines.¹⁰

already revealed that the regioselectivity in favor of the linear Although Table 4 summarizes the first successful examples of

product increases with increasing size of the N-alkyl substi- hydroaminoalkylation reactions of conjugated dienes with

tuent,^7gwe additionally tried to react (E)-1-phenyl-1,3-buta- N-methylbenzylamine (38), complex 6 unfortunately failed to

diene (49) with the sterically more demanding amines N- catalyze a number of closely related reactions. For example,

benzylaniline (35), N-methylcylohexylamine (36), N-methylhexyl- 1-phenyl-substituted 1,3-butadienes bearing additional methyl

amine (37), and N-methylbenzylamine (38). All reactions were or chloro substituents in the 2-position of the diene system

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Table 4 Hydroaminoalkylation of 1,3-dienes with N-methylbenzylamine (38)

Entry

1

Diene

R

Isolated linear product^a

Yield^b(%)

58

Selectivity a/b^c

49

H

7 : 93

2

3

4

50

51

73

p-Cl

67

71

60

8 : 92

9 : 91

p-F

p-MeO

10 : 90

5

6

74

75

o-Me

69

66

13 : 87

11 : 89

o-MeO

^aOnly the isolated, linear product is presented. ^bReaction conditions: (1) N-methylbenzylamine (38, 242 mg, 2.0 mmol), diene (3.0 mmol), 6

(109 mg, 0.2 mmol, 10 mol%), n-hexane (1 mL), 120 °C, 48 h, sealed Schlenk tube; (2) para-toluenesulfonyl chloride (763 mg, 4.0 mmol), pyridine

(10 mL), 25 °C, 16 h. Yields refer to the yield of the isolated linear product (b). ^cGC analysis prior to tosylation and chromatography.

did not undergo the reaction and the 1-alkyl-substituted 1,3- noalkylation of unactivated, sterically demanding 1,1- and 1,2-

butadiene 52 delivered only trace amounts of the expected disubstituted alkenes and styrenes with secondary amines.

hydroaminoalkylation products which could only be detected While corresponding reactions of 1,1-disubstituted alkenes

and characterized by GC/MS analysis. In addition, even a small and styrenes give access to the branched hydroaminoalkylation

variation of the N-methylbenzylamine motif resulted in a lack products exclusively, (E)-β-methylstyrene selectively reacts at

of reactivity. Neither N-ethyl-, N-iso-propyl-, N-cyclohexyl-, the sterically less hindered β-carbon. In addition, with catalyst

N-benzyl-, nor N-(2-phenylethyl)-substituted benzylamines 6, it is also possible for the first time to convert 1-phenyl-sub-

underwent successful hydroaminoalkylation with (E)-1-phenyl- stituted (E)-1,3-butadienes and N-methylbenzylamine into

1,3-butadiene (49) in the presence of catalyst 6.

δ-alkenylamine derivatives.

Conclusions

Experimental

General information

In summary, we have shown that the easily accessible titanium

mono(formamidinate) complex 6^8awhich bears 2,6-diisopro- All reactions were performed under an inert atmosphere of

pylphenyl groups as the amidinate N-substituents is a highly nitrogen in oven-dried Schlenk tubes (Duran glassware,

active catalyst for the regioselective intermolecular hydroami- 100 mL, ø = 30 mm) equipped with Teflon stopcocks and mag-

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netic stirring bars (15 × 4.5 mm). Prior to use, all alkenes, sty- 0.2 mmol, 10 mol%) and n-hexane (0.5 mL). Afterwards the

renes, and amines were distilled and degassed. n-Hexane was dialkylamine (2.0 mmol), the styrene (3.0 mmol), and

purified by distillation from sodium wire and degassed. The n-hexane (0.5 mL) were added. After heating the mixture to

alkenes, styrenes, amines, and n-hexane were stored in a nitro- 180 °C for 96 h, the crude product was transferred to a 100 mL

gen-filled glove box. Catalyst 6^8aand the dienes^7h,iwere syn- round-bottomed flask and the Schlenk tube was rinsed with

thesized according to literature procedures and stored in a dichloromethane (4 × 10 mL). The regioselectivity of the reac-

nitrogen-filled glove box. All other chemicals were purchased tion was determined by GC and subsequently, the combined

from commercial sources and were used without further purifi- solutions were concentrated under vacuum to a total volume

cation. Unless otherwise noted, the ratio of regioisomers was of 10 mL. The resulting mixture was then treated with 2 N

determined by gas chromatography prior to flash column aqueous NaOH (5 mL, 10.0 mmol) and para-toluenesulfonyl

chromatography. For thin layer chromatography, silica on TLC chloride (572 mg, 3.0 mmol). The resulting biphasic mixture

aluminium foils with fluorescent indicator 254 nm was used. was stirred vigorously at room temperature for 20 h before the

The substances were detected with UV light and/or iodine. For solution was partitioned between dichloromethane (50 mL)

flash column chromatography, silica gel (particle size and water (20 mL). The formed layers were separated, the

0.037–0.063 mm) was used. Light petroleum ether aqueous one was extracted with dichloromethane (3 × 10 mL)

(b.p. 40–60 °C, PE), tert-butyl methyl ether (MTBE) and ethyl and the combined organic layers were dried with MgSO₄. After

acetate (EtOAc) used for chromatography were distilled via concentration under vacuum, the product was isolated by flash

Raschig columns at ambient pressure. Other solvents used for column chromatography (SiO₂).

chromatography were distilled prior to use. All products that

General procedure C for the hydroaminoalkylation of

1,3-dienes with N-methylanilines (Table 3)

have already been reported in the literature were identified by

comparison of the obtained ¹H NMR and ¹³C NMR spectra

with those reported in the literature. New compounds were An oven dried Schlenk tube equipped with a Teflon stopcock

additionally characterized by infrared spectroscopy, mass spec- and a magnetic stirring bar was transferred into a nitrogen-

1

trometry, and high resolution mass spectrometry (HRMS). H, filled glovebox and charged with 6 (109 mg, 0.20 mmol,

¹³C and ¹⁹F NMR spectra were recorded at 500, 470, 300, 125 10 mol%), the diene (3.0 mmol), the amine (2.0 mmol), and

and 75 MHz. All ¹H NMR spectra are reported in δ units (ppm) n-hexane (1 mL). Then the tube was sealed and the resulting

relative to the signal of TMS at 0.00 ppm or relative to the mixture was heated to 120 °C for 48 h. After the mixture had

residual solvent signal of CDCl₃at 7.26 ppm. All ¹³C NMR been cooled to room temperature, tert-butyl methyl ether

spectra are reported in δ units (ppm) relative to the central (30 mL) was added and the regioselectivity of the reaction was

line of the triplet for CDCl₃at 77.0 ppm. All ¹⁹F NMR spectra determined by GC. To achieve a better separation of the pro-

are reported in δ units (ppm) relative to the signal of CFCl₃at ducts from remaining N-methylanilines, acetyl chloride (1 M

0.00 ppm. Infrared spectra were recorded either via KBr pellets in CH₂Cl₂, 4 mL, 4 mmol), and triethylamine (405 mg,

or on an ATR spectrometer. Mass spectra and high resolution 4 mmol) were added and the reaction mixture was stirred at

mass spectra (HRMS) were recorded either in EI (with an room temperature for 16 h. Finally, the solvent was removed in

ionization potential of 70 eV) or in ESI mode (ESI, TOF).

the presence of Celite® and the residue was purified by flash

column chromatography (SiO₂).

General procedure A for the hydroaminoalkylation of

disubstituted alkenes and styrenes with N-substituted

arylamines (Tables 1 and 2)

General procedure D for the hydroaminoalkylation of

1,3-dienes with N-methylbenzylamine (38, Table 4)

An oven dried Schlenk tube equipped with a Teflon stopcock An oven dried Schlenk tube equipped with a Teflon stopcock

and a magnetic stirring bar was transferred into a nitrogen- and a magnetic stirring bar was transferred into a nitrogen-

filled glovebox and charged with complex

6 (109 mg, filled glovebox and charged with 6 (109 mg, 0.20 mmol,

0.2 mmol, 10 mol%) and n-hexane (0.5 mL). Afterwards the 10 mol%), the diene (3.0 mmol), N-methylbenzylamine (38,

N-substituted arylamine (2.0 mmol), the alkene or styrene 242 mg, 2.0 mmol), and n-hexane (1 mL). Then the tube was

(3.0 mmol), and n-hexane (0.5 mL) were added. After heating sealed and the resulting mixture was heated to 120 °C for 48 h.

the mixture to 180 °C for 96 h, the mixture was cooled to room After the mixture had been cooled to room temperature, tert-

temperature and dichloromethane (40 mL) was added. Then butyl methyl ether (30 mL) was added and the regioselectivity

the regioselectivity of the reaction was determined by GC (if of the reaction was determined by GC. Then the solvent was

applicable) and finally, the crude product was purified by flash removed under reduced pressure and pyridine (10 mL) and

column chromatography (SiO₂).

para-toluenesulfonyl chloride (763 mg, 4.0 mmol) were added.

After the resulting mixture had been stirred overnight at room

temperature, dichloromethane (50 mL) was added and the

organic mixture was extracted with aqueous HCl (4 M, 50 mL).

General procedure B for the hydroaminoalkylation of

disubstituted styrenes with dialkylamines (Table 2)

An oven dried Schlenk tube equipped with a Teflon stopcock Then the aqueous layer was extracted with dichloromethane

and a magnetic stirring bar was transferred into a nitrogen- (3 × 15 mL) and the combined organic layers were dried with

filled glovebox and charged with complex

6

(109 mg, MgSO₄and concentrated under reduced pressure in the

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presence of silica gel. (Note: The use of Celite® instead of atography, the ratio 23a/23b was determined to be 99 : 1. 23a:

silica gel leads to significantly reduced yields.) Finally, the ¹H NMR (500 MHz, CDCl₃, TMS) δ = 7.28 (br. d, J = 8.2 Hz,

product was purified by flash column chromatography (SiO₂). 2H), 7.22–7.09 (m, 4H), 6.65 (t, J = 7.3 Hz, 1H), 6.53 (d, J = 7.7

Due to the viscosity of the products, removal of remaining sol- Hz, 2H), 3.32 (br. s, 1H), 3.25 (s, 2H), 2.33 (s, 3H), 1.39 (s, 6H)

vents required storage of the products under high vacuum for ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 148.7 (C), 143.6 (C), 135.7

several hours.

Amines 3a^5mand 3b.⁷ⁱGeneral procedure A was used to syn- 55.6 (CH₂), 38.5 (C), 27.5 (CH₃), 20.9 (CH₃) ppm.

thesize 3a and 3b from N-methylaniline (2, 214 mg, 2.0 mmol)

Amine 24b.^7gGeneral procedure A was used to synthesize

(C), 129.2 (CH), 129.1 (CH), 126.0 (CH), 117.0 (CH), 112.7 (CH),

and styrene (1, 313 mg, 3.0 mmol). After purification by flash 24b from N-methylaniline (2, 214 mg, 2.0 mmol) and (E)-

chromatography (PE–EtOAc, 40 : 1), a mixture of 3a and 3b β-methylstyrene (11, 355 mg, 3.0 mmol). After purification by

(406 mg, 1.92 mmol, 96%) was isolated as a yellow oil. Prior to flash chromatography (PE–EtOAc, 95 : 1), 24b (288 mg,

chromatography, the ratio 3a/3b was determined to be 73 : 27. 1.28 mmol, 64%) was isolated as a yellow oil. Prior to chrom-

For characterization, it was possible to separate the regio- atography, the ratio 24a/24b was determined to be 1 : 99. 24b:

isomers by chromatography (PE–EtOAc, 40 : 1). 3a: ¹H NMR ¹H NMR (500 MHz, CDCl₃, TMS) δ = 7.28 (t, J = 7.4 Hz, 2H),

(300 MHz, CDCl₃, TMS) δ = 7.25 (t, J = 7.3 Hz, 2H), 7.19–7.13 7.22–7.11 (m, 5H), 6.67 (br. t, J = 7.3 Hz, 1H), 6.53 (d, J = 7.7

(m, 3H), 7.09 (t, J = 7.7 Hz, 2H), 6.63 (t, J = 7.3 Hz, 1H), 6.51 (d, Hz, 2H), 3.66 (br. s, 1H), 3.08 (dd, J = 12.5, 6.1 Hz, 1H), 2.93

J = 7.8 Hz, 2H), 3.26 (dd, J = 12.4, 6.2 Hz, 1H), 3.16 (dd, J = (dd, J = 12.5, 7.0 Hz, 1H), 2.74 (dd, J = 13.5, 6.4 Hz, 1H), 2.49

12.3, 8.3 Hz, 1H), 2.99 (sext, J = 7.0 Hz, 1H), 1.26 (d, J = 7.0 Hz, (dd, J = 13.5, 7.8 Hz, 1H), 2.06 (octet, J = 6.8 Hz, 1H), 0.96 (d, J

3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 147.8 (C), 144.4 (C), = 6.7 Hz, 3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 148.3 (C),

129.2 (CH), 128.6 (CH), 127.2 (CH), 126.6 (CH), 117.5 (CH), 140.5 (C), 129.2 (CH), 129.1 (CH), 128.3 (CH), 125.9 (CH), 117.0

113.1 (CH), 51.0 (CH₂), 39.1 (CH), 19.7 (CH₃) ppm. 3b: ¹H (CH), 112.7 (CH), 49.8 (CH₂), 41.3 (CH₂), 35.0 (CH), 18.1

NMR (300 MHz, TMS) δ = 7.34–7.24 (m, 2H), 7.24–7.09 (CH₃) ppm.

(m, 5H), 6.69 (t, J = 7.3 Hz, 1H), 6.57 (d, J = 8.1 Hz, 2H), 3.59

Amines 25a and 25b. General procedure A was used to syn-

(br. s, 1H), 3.14 (t, J = 7.0 Hz, 2H), 2.73 (t, J = 7.6 Hz, 2H), 1.94 thesize 25a and 25b from N-methylaniline (2, 214 mg,

(quin, J = 7.3 Hz, 2H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 2.0 mmol) and indene (12, 348 mg, 3.0 mmol). Purification by

148.1 (C), 141.6 (C), 129.2 (CH), 128.4 (CH), 128.4 (CH), 125.9 flash column chromatography (PE–MTBE, 80 : 1) gave three

(CH), 117.4 (CH), 112.9 (CH), 43.5 (CH₂), 33.4 (CH₂), 31.0 fractions as oils. Fraction 1 contained pure compound 25a

(CH₂) ppm.

(30 mg, 0.13 mmol, 7%), fraction 2 contained a mixture of 25a

Amine 21a.^7gGeneral procedure A was used to synthesize and 25b (203 mg, 0.91 mmol, 45%) and fraction 3 contained

21a from N-methylaniline (2, 214 mg, 2.0 mmol) and methy- pure compound 25b (200 mg, 0.90 mmol, 45%) as yellow oils.

lenecyclohexane (7, 289 mg, 3.0 mmol). After purification by Prior to chromatography, the ratio 25a/25b was determined to

flash chromatography (PE–EtOAc, 100 : 1), 21a (364 mg, be 34 : 66. 25a: R_f= 0.13 (PE–MTBE, 80 : 1). ¹H NMR (500 MHz,

1.79 mmol, 90%) was isolated as a yellow oil. Prior to chrom- CDCl₃) δ = 7.33–7.27 (m, 2H), 7.25–7.18 (m, 4H), 6.74 (t, J = 7.3

atography, the ratio 21a/21b was determined to be 99 : 1. 21a: Hz, 1H), 6.67 (d, J = 7.7 Hz, 2H), 3.75 (br. s, 1H), 3.54–3.44 (m,

¹H NMR (300 MHz, CDCl₃, TMS) δ = 7.15 (t, J = 7.4 Hz, 2H), 2H), 3.29 (dd, J = 11.8, 7.3 Hz, 1H), 3.06–2.98 (m, 1H),

6.70–6.56 (m, 3H), 3.59 (br. s, 1H), 2.92 (s, 2H), 1.59–1.18 (m, 2.98–2.89 (m, 1H), 2.39–2.30 (m, 1H), 1.99–1.91 (m, 1H) ppm.

11H), 0.97 (s, 3H) ppm. ¹³C NMR (75 MHz, CDCl₃) δ = 149.1 ¹³C NMR (125 MHz, CDCl₃) δ = 148.4 (C), 144.7 (C), 144.4 (C),

(C), 129.1 (CH), 116.7 (CH), 112.6 (CH), 54.6 (CH₂), 35.8 (CH₂), 129.3 (CH), 126.9 (CH), 126.3 (CH), 124.7 (CH), 124.0 (CH),

34.2 (C), 26.4 (CH₂), 23.5 (CH₃), 22.0 (CH₂) ppm.

117.4 (CH), 112.8 (CH), 48.0 (CH₂), 44.6 (CH), 31.3 (CH₂), 30.0

Amine 22a.^5kGeneral procedure A was used to synthesize (CH₂) ppm. IR (ATR) v_max= 3417 (w), 3047 (w), 3019 (w), 2939

22a from N-methylaniline (2, 214 mg, 2.0 mmol) and α-methyl- (w), 2847 (w), 1601 (s), 1504 (s), 1319 (m), 1260 (m), 744 (vs),

styrene (9, 355 mg, 3.0 mmol). After purification by flash 691 (s) cm⁻¹. GC/MS m/z = 223 ([M]⁺), 106 ([C₇H₈N]⁺), 77

chromatography (PE–EtOAc, 100 : 1), 22a (387 mg, 1.72 mmol, ([C₆H₅]⁺). HRMS (ESI+) m/z calcd for C₁₆H₁₈N 224.1439 ([M +

86%) was isolated as a yellow oil. Prior to chromatography, the H]⁺), found 224.1438. 25b: R_f= 0.10 (PE–MTBE, 80 : 1). ¹H

ratio 22a/22b was determined to be 99 : 1. 22a: ¹H NMR NMR (500 MHz, CDCl₃) δ = 7.25–7.15 (m, 6H), 6.72 (t, J = 7.3

(500 MHz, CDCl₃, TMS) δ = 7.42–7.38 (m, 2H), 7.35 (t, J = 7.0 Hz, 1H), 6.64 (d, J = 7.7 Hz, 2H), 3.74 (br. s, 1H), 3.22 (d, J = 6.7

Hz, 2H), 7.25–7.21 (m, 1H), 7.13 (br. t, J = 7.3 Hz, 2H), 6.66 (br. Hz, 2H), 3.19–3.11 (m, 2H), 2.87–2.75 (m, 3H) ppm. ¹³C NMR

t, J = 7.3 Hz, 1H), 6.53 (br. d, J = 8.5 Hz, 2H), 3.28 (s, 2H), 1.41 (125 MHz, CDCl₃) δ = 148.4 (C), 142.6 (C), 129.2 (CH), 126.3

(s, 6H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 148.7 (C), 146.7 (CH), 124.6 (CH), 117.3 (CH), 112.7 (CH), 48.8 (CH₂), 39.1

(C), 129.1 (CH), 128.5 (CH), 126.2 (CH), 126.1 (CH), 117.1 (CH), (CH), 37.2 (CH₂) ppm. IR (ATR) v_max= 3414 (w), 3048 (w), 3020

112.7 (CH), 55.7 (CH₂), 38.9 (C), 27.4 (CH₃) ppm.

(w), 2929 (w), 2900 (w), 2841 (w), 1601 (s), 1505 (s), 1316 (m),

Amine 23a.^5mGeneral procedure A was used to synthesize 1256 (m), 740 (vs), 690 (s) cm⁻¹. GC/MS m/z = 223 ([M]⁺), 106

23a from N-methylaniline (2, 214 mg, 2.0 mmol) and para- ([C₇H₈N]⁺), 93 ([C₆H₇N]⁺), 77 ([C₆H₅]⁺). HRMS (ESI+) m/z calcd

α-dimethylstyrene (10, 397 mg, 3.0 mmol). After purification for C₁₆H₁₈N 224.1439 ([M + H]⁺), found 224.1436.

by flash chromatography (PE–EtOAc, 100 : 1), 23a (435 mg,

Amines 26a and 26b.^7gGeneral procedure A was used to syn-

1.82 mmol, 91%) was isolated as a yellow oil. Prior to chrom- thesize 26a and 26b from N-methylaniline (2, 214 mg,

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2.0 mmol) and (E)-2-octene (17, 337 mg, 3.0 mmol). After puri- ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 148.5 (C), 129.2 (CH),

fication by flash chromatography (PE–EtOAc, 100 : 1), 127.2 (CH), 125.8 (CH), 117.0 (CH), 112.6 (CH), 49.7 (CH₂),

a

mixture of 26a and 26b (69 mg, 0.32 mmol, 16%) was isolated 33.5 (CH), 29.7 (CH₂), 26.8 (CH₂), 24.7 (CH₂) ppm. IR (neat)

as a yellow oil. Prior to chromatography, the ratio 26a/26b was v_max= 3418 (m), 3051 (w), 3021 (m), 2916 (s), 2837 (m), 1603

determined to be 35 : 65. ¹H NMR (500 MHz, CDCl₃, TMS, (s), 1507 (s), 1433 (m), 1323 (s), 1254 (s), 1179 (w), 748 (s), 692

mixture of two regioisomers) signals of the major regioisomer (s) cm⁻¹. GC/MS m/z = 187 ([M]⁺), 106 ([C₇H₈N]⁺), 77 ([C₆H₅]⁺).

26b: δ = 7.09 (t, J = 8.4 Hz, 2H), 6.60 (t, J = 7.3 Hz, 1H), 6.53 (d, HRMS (ESI+) m/z calcd for C₁₃H₁₈N 188.1439 ([M + H]⁺), found

J = 7.6 Hz, 2H), 3.59 (br. s, 1H), 3.01–2.92 (m, 1H), 2.80 (dd, J = 188.1435.

12.2, 7.3 Hz, 1H), 1.66 (octet, J = 6.6 Hz, 1H), 1.41–1.05 (m,

Amine 31.¹²General procedure A was used to synthesize 31

13H), 0.89 (d, J = 6.7 Hz, 3H), 0.81 (t, J = 6.8 Hz, 3H) ppm; from N-methylaniline (2, 214 mg, 2.0 mmol) and 3-methoxycy-

important signals of the minor regioisomer 26a: δ = 3.01–2.92 clohexene (30, 337 mg, 3.0 mmol). After purification by flash

(m, 2H), 1.49 (sept, J = 6.1 Hz, 1H), 0.84 (t, J = 7.4 Hz, 3H), 0.82 chromatography (PE–Et₂O, 80 : 1

→ PE–Et₂O, 40 : 1), 31

(t, J = 6.8 Hz, 3H) ppm. ¹³C NMR (125 MHz, CDCl₃, mixture of (228 mg, 1.22 mmol, 61%) was isolated as a yellow oil. 31: H

two regioisomers) signals of the major regioisomer 26b: δ = NMR (500 MHz, CDCl₃, TMS) δ = 7.27–7.18 (m, 2H), 6.79 (d, J =

148.7 (C), 129.2 (CH), 116.9 (CH), 112.6 (CH), 50.3 (CH₂), 34.8 8.3 Hz, 2H), 6.69 (t, J = 7.2 Hz, 1H), 5.94–5.88 (m, 1H), 5.63 (br.

(CH₂), 32.9 (CH), 31.9 (CH₂), 29.6 (CH₂), 26.9 (CH₂), 22.7 d, J = 10.2 Hz, 1H), 4.48–4.41 (m, 1H), 2.78 (s, 3H), 2.12–1.95

(CH₂), 18.1 (CH₃), 14.1 (CH₃) ppm; signals of the minor regio- (m, 2H), 1.91–1.77 (m, 2H), 1.71–1.52 (m, 2H) ppm. ¹³C NMR

isomer 26a: δ = 148.6 (C), 129.2 (CH), 116.9 (CH), 112.6 (CH), (125 MHz, CDCl₃) δ = 149.7 (C), 130.6 (CH), 129.9 (CH), 129.1

47.0 (CH₂), 39.1 (CH), 32.3 (CH₂), 31.6 (CH₂), 26.4 (CH₂), 24.5 (CH), 116.2 (CH), 112.8 (CH), 54.9 (CH), 32.4 (CH₃), 25.3 (CH₂),

(CH₂), 22.7 (CH₂), 14.1 (CH₃), 10.9 (CH₃) ppm. IR (neat, 24.9 (CH₂), 21.5 (CH₂) ppm.

1

mixture of two regioisomers) v_max= 3421 (s), 3052 (w), 3021

Amine 39a. General procedure A was used to synthesize 39a

(w), 2957 (s), 2926 (s), 2856 (s), 1603 (s), 1506 (s), 1465 (m), from para-methyl-N-methylaniline (32, 242 mg, 2.0 mmol) and

1320 (m), 1260 (m), 747 (s), 691 (s) cm⁻¹. GC/MS m/z = 219 α-methylstyrene (9, 355 mg, 3.0 mmol). After purification by

([M]⁺), 106 ([C₇H₈N]⁺), 77 ([C₆H₅]⁺).

flash chromatography (PE–EtOAc, 95 : 1), 39a (422 mg,

Amine 27.¹¹General procedure A was used to synthesize 27 1.76 mmol, 88%) was isolated as a yellow oil. Prior to chrom-

from N-methylaniline (2, 214 mg, 2.0 mmol) and cyclopentene atography, the ratio 39a/39b was determined to be 99 : 1. 39a:

(18, 204 mg, 3.0 mmol). After purification by flash chromato- ¹H NMR (500 MHz, CDCl₃, TMS) δ = 7.39 (br. d, J = 7.8 Hz,

graphy (PE–EtOAc, 80 : 1), 27 (262 mg, 1.49 mmol, 75%) was 2H), 7.34 (t, J = 7.8 Hz, 2H), 7.22 (br. t, J = 7.3 Hz, 1H), 6.94 (d,

1

isolated as a yellow oil. 27: H NMR (300 MHz, CDCl₃, TMS) δ J = 8.0 Hz, 2H), 6.45 (d, J = 8.4 Hz, 2H), 3.25 (s, 2H), 3.17 (br. s,

= 7.17 (br. t, J = 7.9 Hz, 2H), 6.68 (br. t, J = 7.3 Hz, 1H), 6.61 1H), 2.21 (s, 3H), 1.40 (s, 6H) ppm. ¹³C NMR (125 MHz, CDCl₃)

(br. d, J = 8.1 Hz, 2H), 3.64 (br. s, 1H), 3.02 (d, J = 7.2 Hz, 2H), δ 146.8 (C), 146.5 (C), 129.6 (CH), 128.5 (CH), 126.2 (C), 126.1

2.15 (sept, J = 7.5 Hz, 1H), 1.91–1.72 (m, 2H), 1.67–1.47 (m, (CH), 126.1 (CH), 112.8 (CH), 56.1 (CH₂), 38.9 (C), 27.4 (CH₃),

4H), 1.37–1.17 (m, 2H) ppm. ¹³C NMR (75 MHz, CDCl₃) δ = 20.3 (CH₃) ppm. IR (neat) v_max= 3413 (m), 3021 (m), 2964 (m),

148.6 (C), 129.2 (CH), 117.0 (CH), 112.6 (CH), 49.5 (CH₂), 39.4 2920 (m), 1619 (s), 1521 (s), 1480 (m), 1317 (m), 1294 (m), 1251

(CH), 30.7 (CH₂), 25.3 (CH₂) ppm.

(m), 806 (s), 764 (m), 700 (s) cm⁻¹. GC/MS m/z = 239 ([M]⁺), 120

Amine 28.^5kGeneral procedure A was used to synthesize 28 ([C₈H₁₀N]⁺), 91 ([C₇H₇]⁺). HRMS (ESI+) m/z calcd for

from N-methylaniline (2, 214 mg, 2.0 mmol) and cyclohexene C₁₇H₂₁NNa 262.1572 ([M + Na]⁺), found 262.1567.

(19, 246 mg, 3.0 mmol). After purification by flash chromato-

Amine 40a. General procedure A was used to synthesize 40a

graphy (PE–EtOAc, 100 : 1), 28 (272 mg, 1.44 mmol, 72%) was from para-fluoro-N-methylaniline (33, 250 mg, 2.0 mmol) and

isolated as a yellow oil. 28: ¹H NMR (500 MHz, CDCl₃, TMS) α-methylstyrene (9, 355 mg, 3.0 mmol). After purification by

δ = 7.18–7.13 (m, 2H), 6.67 (tt, J = 7.3, 1.0 Hz, 1H), 6.61–6.56 flash chromatography (PE–EtOAc, 80 : 1), 40a (475 mg,

(m, 2H), 3.71 (br. s, 1H), 2.95 (d, J = 6.7 Hz, 2H), 1.85–1.78 (m, 1.95 mmol, 98%) was isolated as a yellow oil. Prior to chrom-

2H), 1.78–1.71 (m, 2H), 1.70–1.65 (m, 1H), 1.64–1.52 (m, 1H), atography, the ratio 40a/40b was determined to be 99 : 1. 40a:

1.31–1.13 (m, 3H), 0.98 (qd, J = 12.1, 3.1 Hz, 2H) ppm. ¹³C ¹H NMR (300 MHz, CDCl₃, TMS) δ = 7.43–7.30 (m, 4H), 7.23

NMR (125 MHz, CDCl₃) δ = 148.6 (C), 129.2 (CH), 116.9 (CH), (tt, J = 6.8, 1.7 Hz, 1H), 6.87–6.77 (m, 2H), 6.49–6.39 (m, 2H),

112.7 (CH), 50.6 (CH₂), 37.6 (CH), 31.3 (CH₂), 26.6 (CH₂), 26.0 3.22 (s, 2H), 3.21 (br. s, 1H), 1.41 (s, 6H) ppm. ¹³C NMR

1

(CH₂) ppm.

(75 MHz, CDCl₃) δ = 155.6 (d, J_C,F= 234.5 Hz, C), 146.6 (C),

2

Amine 29. General procedure A was used to synthesize 29 145.1 (C), 128.5 (CH), 126.2 (CH), 126.0 (CH), 115.5 (d, J_C,F

=

from N-methylaniline (2, 214 mg, 2.0 mmol) and 1,4-cyclohexa- 22.2 Hz, CH), 113.5 (d, ³J_C,F= 7.4 Hz, CH), 56.5 (CH₂), 38.8 (C),

diene (20, 240 mg, 3.0 mmol). After purification by flash 27.4 (CH₃) ppm. IR (neat) v_max= 3412 (w), 3059 (w), 2965 (m),

chromatography (PE–EtOAc, 90 : 1), 29 (348 mg, 1.86 mmol, 1612 (w), 1511 (s), 1481 (m), 1221 (s), 819 (s), 765 (s), 701 (s)

93%) was isolated as a yellow oil. 29: ¹H NMR (500 MHz, cm⁻¹. GC/MS m/z = 243 ([M]⁺), 124 ([C₇H₇NF]⁺), 91 ([C₇H₇]⁺).

CDCl₃, TMS) δ = 7.17 (br. t, J = 6.9 Hz, 2H), 6.68 (br. t, J = 7.3 HRMS (ESI+) m/z calcd for C₁₆H₁₉NF 244.1502 ([M + H]⁺),

Hz, 1H), 6.61 (br. d, J = 8.5 Hz, 2H), 5.73–5.63 (m, 2H), 3.73 found 244.1503.

(br. s, 1H), 3.10–3.01 (m, 2H), 2.24–2.15 (m, 1H), 2.13–2.03 (m,

Amine 41a. General procedure A was used to synthesize 41a

2H), 1.96–1.83 (m, 2H), 1.83–1.74 (m, 1H), 1.39–1.28 (m, 1H) from para-phenoxy-N-methylaniline (34, 399 mg, 2.0 mmol)

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and α-methylstyrene (9, 355 mg, 3.0 mmol). After purification (CH₃) ppm. IR (neat) v_max= 2958 (s), 2929 (s), 2858 (m), 1599

by flash chromatography (PE–EtOAc, 60 : 1), 41a (424 mg, (m), 1495 (m), 1465 (m), 1340 (s), 1160 (s), 1091 (m), 815 (m),

1.34 mmol, 67%) was isolated as a yellow solid. Prior to chrom- 757 (m), 702 (s), 655 (s) cm⁻¹. MS (ESI+) m/z = 410 ([M + Na]⁺).

atography, the ratio 41a/41b was determined to be 99 : 1. 41a: HRMS (ESI+) m/z calcd for C₂₃H₃₃NO₂SNa 410.2130 ([M +

¹H NMR (500 MHz, CDCl₃, TMS) δ = 7.40 (br. d, J = 8.3 Hz, Na]⁺), found 410.2123.

2H), 7.37–7.32 (m, 2H), 7.27–7.21 (m, 3H), 6.98 (t, J = 7.4 Hz,

Amine 44b.^7bGeneral procedure A was used to synthesize

1H), 6.90 (d, J = 8.4 Hz, 2H), 6.85 (br. d, J = 8.8 Hz, 2H), 6.51 44b from para-methyl-N-methylaniline (32, 242 mg, 2.0 mmol)

(br. d, J = 8.8 Hz, 2H), 3.26 (br. s, 3H), 1.42 (s, 6H) ppm. ¹³C and (E)-β-methylstyrene (11, 355 mg, 3.0 mmol). After purifi-

NMR (125 MHz, CDCl₃) δ = 159.1 (C), 147.3 (C), 146.6 (C), cation by flash chromatography (PE–EtOAc, 95 : 1), 44b

145.4 (C), 129.4 (CH), 128.5 (CH), 126.2 (CH), 126.0 (CH), 121.8 (150 mg, 0.63 mmol, 31%) was isolated as a yellow oil. Prior to

(CH), 121.2 (CH), 116.9 (CH), 113.7 (CH), 56.4 (CH₂), 38.8 (C), chromatography, the ratio 44a/44b was determined to be 1 : 99.

1

27.4 (CH₃) ppm. IR (neat) v_max= 3412 (s), 3053 (w), 3034 (w), 44b: H NMR (500 MHz, CDCl₃, TMS) δ = 7.28 (t, J = 7.4 Hz,

2965 (m), 2924 (w), 2854 (w), 1613 (s), 1517 (s), 1489 (m), 1233 2H), 7.22–7.13 (m, 3H), 6.96 (d, J = 8.1 Hz, 2 H), 6.47 (br. d, J =

(s), 1163 (m), 832 (m), 752 (m), 704 (m), 692 (m) cm⁻¹. GC/MS 8.4 Hz, 2 H), 3.53 (br. s, 1H), 3.06 (dd, J = 12.4, 6.0 Hz, 1H),

m/z = 317 ([M]⁺), 198 ([C₁₃H₁₂NO]⁺), 91 ([C₇H₇]⁺). HRMS (ESI+) 2.92 (dd, J = 12.4, 6.9 Hz, 1H), 2.74 (dd, J = 13.4, 6.4 Hz, 1H),

m/z calcd for C₂₂H₂₃NONa 340.1677 ([M + Na]⁺), found 2.49 (dd, J = 13.5, 7.9 Hz, 1H), 2.22 (s, 3H), 2.06 (oct, J = 6.7 Hz,

340.1681.

1H), 0.96 (d, J = 6.7 Hz, 3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ

para-Toluenesulfonamide 42a. General procedure B was = 146.1 (C), 140.6 (C), 129.7 (CH), 129.1 (CH), 128.2 (CH), 126.3

used to synthesize 42a from N-methylcyclohexylamine (36, (C), 125.9 (CH), 112.9 (CH), 50.2 (CH₂), 41.4 (CH₂), 35.0 (CH),

226 mg, 2.0 mmol) and α-methylstyrene (9, 355 mg, 20.3 (CH₃), 18.1 (CH₃) ppm.

3.0 mmol). After purification by flash chromatography (PE–

Amine 45b. General procedure A was used to synthesize 45b

EtOAc, 80 : 1 → PE–EtOAc, 40 : 1 → PE–EtOAc, 20 : 1), 42a from para-fluoro-N-methylaniline (33, 250 mg, 2.0 mmol) and

(107 mg, 0.28 mmol, 14%) was isolated as a colorless solid. (E)-β-methylstyrene (11, 355 mg, 3.0 mmol). After purification

Prior to tosylation and chromatography, the ratio of the by flash chromatography (PE–EtOAc, 80 : 1), 45b (316 mg,

branched and the linear product was determined to be 99 : 1. 1.30 mmol, 65%) was isolated as a red oil. Prior to chromato-

1

42a: H NMR (500 MHz, CDCl₃, TMS) δ = 7.68 (d, J = 8.3 Hz, graphy, the ratio 45a/45b was determined to be 2 : 98. 45b: H

2H), 7.40–7.35 (m, 2H), 7.32 (br. t, J = 7.8 Hz, 2H), 7.26–7.24 NMR (300 MHz, CDCl₃, TMS) δ = 7.37–7.11 (m, 5H), 6.91–6.79

(m, 2H), 7.21 (br. t, J = 7.3 Hz, 1H), 3.44 (s, 2H), 2.53–2.45 (m, (m, 2H), 6.50–6.38 (m, 2H), 3.52 (br. s, 1H), 3.03 (dd, J = 12.3,

1H), 2.41 (s, 3H), 1.39 (s, 6H), 1.35–1.12 (m, 7H), 0.74–0.59 (m, 6.1 Hz, 1H), 2.90 (dd, J = 12.3, 6.9 Hz, 1H), 2.73 (dd, J = 13.5,

3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ 147.9 (C), 142.7 (C), 6.5 Hz, 1H), 2.51 (dd, J = 13.5, 7.7 Hz, 1H), 2.05 (oct, J = 6.7 Hz,

139.2 (C), 129.4 (CH), 128.2 (CH), 127.3 (CH), 126.3 (CH), 126.1 1H), 0.97 (d, J = 6.7 Hz, 3H) ppm. ¹³C NMR (75 MHz, CDCl₃) δ

(CH), 60.9 (CH), 59.4 (CH₂), 39.0 (C), 31.4 (CH₂), 27.3 (CH₃), = 155.6 (d, ¹J_C,F= 234.4 Hz, C), 144.7 (C), 140.4 (C), 129.1 (CH),

26.6 (CH₂), 25.1 (CH₂), 21.5 (CH₃) ppm. IR (neat) v_max= 3029 128.3 (CH), 126.0 (CH), 115.6 (d, ²J_C,F= 22.2 Hz, CH), 113.4 (d,

(w), 2940 (m), 2859 (m), 1601 (s), 1494 (m), 1371 (s), 1161 (s), ³J_C,F= 7.4 Hz, CH), 50.5 (CH₂), 41.4 (CH₂), 35.0 (CH), 18.1

1045 (w), 816 (m), 761 (s), 705 (s) cm⁻¹. MS (ESI+) m/z = 408 (CH₃) ppm. IR (neat) v_max= 3422 (m), 3061 (w), 3027 (m), 2958

([M + Na]⁺). HRMS (ESI+) m/z calcd for C₂₃H₃₁NO₂SNa (m), 2925 (m), 1612 (m), 1511 (s), 1454 (m), 1319 (w), 1256 (m),

408.1973 ([M + Na]⁺), found 408.1980.

1221 (s), 819 (s), 741 (s), 701 (s) cm⁻¹. GC/MS m/z = 243 ([M]⁺),

para-Toluenesulfonamide 43a. General procedure B was 124 ([C₇H₇NF]⁺), 91 ([C₇H₇]⁺). HRMS (ESI+) m/z calcd for

used to synthesize 43a from N-methylhexylamine (37, 230 mg, C₁₆H₁₉FN 244.1502 ([M + H]⁺), found 244.1496.

2.0 mmol) and α-methylstyrene (9, 355 mg, 3.0 mmol). After

Amine 46b. General procedure A was used to synthesize 46b

purification by flash chromatography (PE–EtOAc, 80 : 1 → PE– from para-phenoxy-N-methylaniline (34, 399 mg, 2.0 mmol)

EtOAc, 40 : 1 → PE–EtOAc, 30 : 1), a mixture of 43a and tosy- and (E)-β-methylstyrene (11, 355 mg, 3.0 mmol). After purifi-

lated N-methylhexylamine (421 mg) was isolated as a colorless cation by flash chromatography (PE–EtOAc, 80 : 1 → PE–EtOAc,

1

oil. According to H NMR spectroscopy, the mixture contained 20 : 1), 46b (88 mg, 0.28 mmol, 14%) was isolated as a dark

380 mg of 43a (0.98 mmol, 49%) and 41 mg of tosylated N- yellow solid. Prior to chromatography, the ratio 46a/46b was

1

methylhexylamine (0.15 mmol). Prior to tosylation and chrom- determined to be 1 : 99. 46b: H NMR (500 MHz, CDCl₃, TMS)

atography, the ratio of the branched and the linear product δ = 7.31–7.24 (m, 4H), 7.23–7.14 (m, 3H), 6.99 (br. t, J = 7.4 Hz,

was determined to be 99 : 1. 43a: ¹H NMR (500 MHz, CDCl₃, 1H), 6.92 (br. d, J = 7.7 Hz, 2H), 6.87 (br. d, J = 8.8 Hz, 2H),

TMS) δ = 7.65 (d, J = 8.3 Hz, 2H), 7.37 (br. d, J = 8.1 Hz, 2H), 6.54 (br. d, J = 8.9 Hz, 2H), 3.58 (br. s, 1H), 3.08 (dd, J = 12.3,

7.33–7.24 (m, 4 H), 7.19 (br. t, J = 7.3 Hz, 1H), 3.39 (s, 2H), 6.0 Hz, 1H), 2.94 (dd, J = 12.3, 7.0 Hz, 1H), 2.75 (dd, J = 13.5,

2.54–2.47 (m, 2H), 2.41 (s, 3H), 1.41 (s, 6H), 1.12–0.98 (m, 3H), 6.5 Hz, 1H), 2.52 (dd, J = 13.5, 7.7 Hz, 1H), 2.08 (oct, J = 6.7 Hz,

0.95–0.85 (m, 3H), 0.78 (t, J = 7.3 Hz, 3H), 0.62 (pent, J = 7.6 1H), 0.99 (d, J = 6.7 Hz, 3H) ppm. ¹³C NMR (125 MHz, CDCl₃)

Hz, 2H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 147.4 (C), 142.9 δ = 159.2 (C), 147.4 (C), 145.1 (C), 140.5 (C), 129.5 (CH), 129.1

(C), 137.3 (C), 129.5 (CH), 128.2 (CH), 127.2 (CH), 126.1 (CH), (CH), 128.3 (CH), 126.0 (CH), 121.9 (CH), 121.2 (CH), 117.1

126.0 (CH), 59.7 (CH₂), 49.3 (CH₂), 39.0 (C), 31.1 (CH₂), 27.1 (CH), 113.7 (CH), 50.5 (CH₂), 41.4 (CH₂), 35.1 (CH), 18.1 (CH₃)

(CH₃), 27.1 (CH₂), 26.3 (CH₂), 22.4 (CH₂), 21.5 (CH₃), 13.9 ppm. IR (neat) v_max= 3026 (m), 2957 (m), 2925 (m), 2870 (m),

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1613 (m), 1589 (m), 1512 (s), 1488 (s), 1232 (s), 869 (s), 832 (s), (115 mg, 0.41 mg, 21%). Fraction 3 contained pure compound

745 (s), 700 (s), 692 (s) cm⁻¹. GC/MS m/z = 317 ([M]⁺), 198 60b (140 mg, 0.50 mmol, 25%). Prior to acetylation and chrom-

([C₁₃H₁₂NO]⁺), 91 ([C₇H₇]⁺). HRMS (ESI+) m/z calcd for atography, the ratio of the branched and the linear product

C₂₂H₂₄NO 318.1858 ([M + H]⁺), found 318.1854.

was determined to be 55 : 45. 60a: R_f= 0.16 (PE–MTBE, 2 : 1).

para-Toluenesulfonamide 47b. General procedure B was ¹H NMR (500 MHz, CDCl₃) δ = 7.39 (t, J = 7.5 Hz, 2H),

used to synthesize 47b from N-methylcyclohexylamine (36, 7.35–7.27 (m, 5H), 7.22–7.20 (m, 1H), 7.17 (d, J = 7.4 Hz, 2H),

226 mg, 2.0 mmol) and (E)-β-methylstyrene (11, 355 mg, 6.37 (d, J = 15.8 Hz, 1H), 6.06 (dd, J = 15.8, 8.5 Hz, 1H), 3.80

3.0 mmol). After purification by flash chromatography (PE– (dd, J = 13.5, 8.8 Hz, 1H), 3.73 (dd, J = 13.5, 6.5 Hz, 1H), 2.62

EtOAc, 80 : 1 → PE–EtOAc, 40 : 1 → PE–EtOAc, 20 : 1), 47b (hept, J = 6.9 Hz, 1H), 1.81 (s, 3H), 1.08 (d, J = 6.8 Hz, 3H)

(294 mg, 0.76 mmol, 38%) was isolated as a colorless solid. ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 170.6 (C), 143.4 (C), 137.5

Prior to tosylation and chromatography, the ratio of the α- and (C), 133.9 (CH), 129.9 (CH), 129.6 (CH), 128.5 (CH), 128.3 (CH),

the β-alkylated product was determined to be 1 : 99. 47b: ¹H 127.7 (CH), 127.0 (CH), 126.1 (CH), 54.5 (CH₂), 36.6 (CH), 22.8

NMR (300 MHz, CDCl₃, TMS) δ = 7.64 (d, J = 8.3 Hz, 2H), (CH₃), 18.4 (CH₃) ppm. IR (ATR) v_max= 3057 (w), 3025 (w),

7.35–7.10 (m, 7H), 3.66–3.53 (m, 1H), 3.06 (dd, J = 14.4, 6.9, 2967 (w), 2927 (w), 2871 (w), 1656 (vs), 1594 (m), 1494 (s), 1394

1H), 2.97 (dd, J = 14.4, 7.7, 1H), 2.82 (dd, J = 13.0, 5.0 Hz, 1H), (s), 1292 (m), 1277 (m), 966 (m), 749 (s), 695 (vs) cm⁻¹. MS

2.40 (s, 3H), 2.36–2.11 (m, 2H), 1.77–1.49 (m, 5H), 1.38–1.12 (ESI+) m/z = 302 ([M + Na]⁺). HRMS (ESI+) m/z calcd for

(m, 5H), 0.90 (d, J = 6.4 Hz, 3H) ppm. ¹³C NMR (125 MHz, C₁₉H₂₁NONa 302.1521 ([M + Na]⁺), found 302.1514. 60b: R_f=

1

CDCl₃) δ = 142.7 (C), 140.8 (C), 138.0 (C), 129.5 (CH), 129.0 0.11 (PE–MTBE, 2 : 1). H NMR (500 MHz, CDCl₃) δ = 7.43 (t,

(CH), 128.2 (CH), 126.9 (CH), 125.8 (CH), 58.5 (CH), 50.2 J = 7.6 Hz, 2H), 7.35 (t, J = 7.4 Hz, 1H), 7.31–7.25 (m, 4H),

(CH₂), 41.0 (CH₂), 35.8 (CH), 31.9 (CH₂), 31.8 (CH₂), 26.2 7.19–7.15 (m, 3H), 6.33 (d, J = 15.8 Hz, 1H), 6.16 (dt, J = 15.8,

(CH₂), 26.2 (CH₂), 25.4 (CH₂), 21.4 (CH₃), 17.5 (CH₃) ppm. IR 6.8 Hz, 1H), 3.78–3.73 (m, 2H), 2.25–2.18 (m, 2H), 1.84 (s, 3H),

(neat) v_max= 3027 (m), 2935 (s), 2856 (s), 1599 (s), 1494 (s), 1.70 (pent, J = 7.6 Hz, 2H) ppm. ¹³C NMR (125 MHz, CDCl₃)

1453 (s), 1334 (s), 1155 (s), 1090 (m), 1005 (m), 988 (m), 849 δ = 170.3 (C), 143.1 (C), 137.6 (C), 130.3 (CH), 129.7 (CH), 129.6

(m), 814 (m), 742 (m), 702 (s), 661 (s) cm⁻¹. MS (ESI+) m/z = (CH), 128.4 (CH), 128.1 (CH), 127.8 (CH), 126.9 (CH), 125.9

408 ([M + Na]⁺). HRMS (ESI+) m/z calcd for C₂₃H₃₁NO₂NaS (CH), 48.7 (CH₂), 30.3 (CH₂), 27.4 (CH₂), 22.8 (CH₃). IR (ATR)

408.1973 ([M + Na]⁺), found 408.1967.

v_max= 3060 (w), 3027 (w), 2931 (w), 2860 (w), 1655 (vs), 1596 (m),

para-Toluenesulfonamide 48b. General procedure B was 1496 (s), 1397 (s), 1296 (m), 1280 (m), 968 (m), 744 (m), 698 (vs)

used to synthesize 48b from N-methylhexylamine (37, 230 mg, cm⁻¹. MS (ESI+) m/z = 302 ([M + Na]⁺). HRMS (ESI+) m/z calcd for

2.0 mmol) and (E)-β-methylstyrene (11, 355 mg, 3.0 mmol). C₁₉H₂₁NONa 302.1521 ([M + Na]⁺), found 302.1511.

After purification by flash chromatography (PE–EtOAc, 80 : 1 →

(E)-N-(2-Methyl-4-phenylbut-3-en-1-yl)-N-(4-phenoxyphenyl)-

PE–EtOAc, 40 : 1 → PE–EtOAc, 20 : 1), 48b (322 mg, 0.83 mmol, acetamide (61a) and (E)-N-(4-phenoxyphenyl)-N-(5-phenylpent-

41%) was isolated as a colorless oil. Prior to tosylation and 4-en-1-yl)acetamide (61b). General procedure C was used to

chromatography, the ratio of the α- and the β-alkylated product synthesize 61a and 61b from para-phenoxy-N-methylaniline

was determined to be 1 : 99. 48b: ¹H NMR (500 MHz, CDCl₃, (34, 399 mg, 2.0 mmol) and (E)-1-phenyl-1,3-butadiene (49,

TMS) δ = 7.64 (d, J = 8.3 Hz, 2H), 7.30–7.25 (m, 4H), 7.19 (t, J = 391 mg, 3.0 mmol). Purification by flash column chromato-

7.4 Hz, 1H), 7.13 (d, J = 7.1 Hz, 2H), 3.12–2.96 (m, 3H), 2.92 graphy (PE–MTBE, 2 : 1) gave three fractions as oils. Fraction 1

(dd, J = 13.7, 8.0 Hz, 1H), 2.77 (dd, J = 13.6, 5.7 Hz, 1H), 2.41 contained pure compound 61a (62 mg, 0.17 mmol, 8%) and

(s, 3H), 2.34 (dd, J = 13.6, 8.8 Hz, 1H), 2.12–2.01 (m, 1H), fraction 2 contained a mixture of 61a and 61b (198 mg,

1.51–1.40 (m, 2H), 1.30–1.15 (m, 6H), 0.89 (d, J = 6.6 Hz, 3H), 0.53 mmol, 27%). Fraction 3 contained pure compound 61b

0.87 (t, J = 7.0 Hz, 3 H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = (74 mg, 0.20 mmol, 10%). Prior to acetylation and chromato-

142.9 (C), 140.4 (C), 136.7 (C), 129.5 (CH), 129.0 (CH), 128.2 graphy, the ratio of the branched and the linear product was

(CH), 127.2 (CH), 125.9 (CH), 54.6 (CH₂), 49.2 (CH₂), 40.9 determined to be 54 : 46. 61a: R_f= 0.22 (PE–MTBE, 2 : 1). ¹H

(CH₂), 34.3 (CH), 31.3 (CH₂), 28.4 (CH₂), 26.5 (CH₂), 22.5 NMR (500 MHz, CDCl₃) δ = 7.40–7.35 (m, 2H), 7.33–7.27 (m,

(CH₂), 21.5 (CH₃), 17.5 (CH₃), 14.0 (CH₃) ppm. IR (neat) v_max

=

4H), 7.22–7.14 (m, 2H), 7.11 (br. d, J = 8.8 Hz, 2H), 7.05 (br. d,

3027 (m), 2928 (s), 2870 (s), 1599 (m), 1495 (m), 1455 (s), 1340 J = 7.7 Hz, 2H), 6.99 (br. d, J = 8.8 Hz, 2H), 6.38 (d, J = 15.9 Hz,

(s), 1161 (s), 1191 (m), 981 (m), 815 (m), 741 (s), 701 (m), 655 1H), 6.07 (dd, J = 15.9, 8.5 Hz, 1H), 3.78 (dd, J = 13.4, 8.9 Hz,

(s) cm⁻¹. MS (ESI+) m/z = 410 ([M + Na]⁺). HRMS (ESI+) m/z 1H), 3.72 (dd, J = 13.4, 6.4 Hz, 1H), 2.70–2.60 (m, 1H), 1.84 (s,

calcd for C₂₃H₃₃NO₂SNa 410.2130 ([M + Na]⁺), found 410.2126. 3H), 1.10 (d, J = 6.8 Hz, 3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ

(E)-N-(2-Methyl-4-phenylbut-3-en-1-yl)-N-phenylacetamide = 170.7 (C), 156.8 (C), 156.3 (C), 138.1 (C), 137.4 (C), 133.9

(60a) and (E)-N-phenyl-N-(5-phenylpent-4-en-1-yl)acetamide (CH), 129.9 (CH), 129.9 (CH), 129.5 (CH), 128.5 (CH), 127.0

(60b). General procedure C was used to synthesize 60a and (CH), 126.1 (CH), 124.0 (CH), 119.4 (CH), 119.0 (CH), 54.5

60b from N-methylaniline (2, 214 mg, 2.0 mmol) and (E)-1- (CH₂), 36.6 (CH), 22.8 (CH₃), 18.4 (CH₃) ppm. IR (ATR) v_max

=

phenyl-1,3-butadiene (49, 391 mg, 3.0 mmol). Purification by 3059 (w), 3025 (w), 2964 (w), 2926 (w), 2869 (w), 1656 (vs), 1588

flash column chromatography gave three fractions as oils. (m), 1504 (s), 1488 (vs), 1393 (m), 1234 (vs), 967 (m), 870 (m),

Fraction 1 contained pure compound 60a (151 mg, 0.54 mmol, 844 (m), 749 (s), 692 (s) cm⁻¹. MS (ESI+) m/z = 372 ([M + H]⁺).

27%) and fraction 2 contained a mixture of 60a and 60b HRMS (ESI+) m/z calcd for C₂₅H₂₅NO₂Na 394.1783 ([M + Na]⁺),

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found 394.1787. 61b: R_f= 0.14 (PE–MTBE, 2 : 1). ¹H NMR compound 63b (107 mg, 0.30 mmol, 14%). Prior to acetylation

(500 MHz, CDCl₃) δ = 7.41–7.36 (m, 2H), 7.34–7.26 (m, 4H), and chromatography, the ratio of the branched and the linear

7.21–7.15 (m, 2H), 7.12 (br. d, J = 8.8 Hz, 2H), 7.07 (br. d, J = product was determined to be 53 : 47. 63a: R_f= 0.28 (PE–

7.7 Hz, 2H), 7.02 (br. d, J = 8.8 Hz, 2H), 6.36 (d, J = 15.9 Hz, MTBE, 1 : 1). ¹H NMR (500 MHz, CDCl₃) δ = 7.31–7.27 (m, 4H),

1H), 6.19 (dt, J = 15.9, 6.9 Hz, 1H), 3.76–3.71 (m, 2H), 2.24 (q, 7.24–7.17 (m, 5H), 6.36 (d, J = 15.9 Hz, 1H), 6.01 (dd, J = 15.8,

J = 7.4 Hz, 2H), 1.87 (s, 3H), 1.72 (pent, J = 7.6 Hz, 2H) ppm. 8.6 Hz, 1H), 3.79–3.70 (m, 2H), 2.68–2.58 (m, 1H), 1.82 (s, 3H),

¹³C NMR (125 MHz, CDCl₃) δ = 170.3 (C), 157.0 (C), 156.2 (C), 1.08 (d, J = 6.8 Hz, 3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ =

137.8 (C), 137.5 (C), 130.3 (CH), 129.9 (CH), 129.6 (CH), 129.3 170.4 (C), 148.2 (C), 142.0 (C), 137.3 (C), 133.7 (CH), 130.2

(CH), 128.4 (CH), 126.8 (CH), 125.9 (CH), 124.0 (CH), 119.4 (CH), 129.8 (CH), 128.5 (CH), 127.2 (CH), 126.1 (CH), 122.0

1

(CH), 119.1 (CH), 48.7 (CH₂), 30.2 (CH₂), 27.4 (CH₂), 22.8 (CH₃) (CH), 120.4 (q, J_C,F= 258.0 Hz, CF₃), 154.7 (CH₂), 36.7 (CH),

ppm. IR (ATR) v_max= 3062 (w), 3028 (w), 2926 (w), 2851 (w), 22.8 (CH₃), 18.4 (CH₃) ppm. ¹⁹F NMR (500 MHz, CDCl₃) δ =

1658 (s), 1506 (s), 1489 (s), 1397 (m), 1294 (m), 1233 (vs), 968 −58.0 ppm. IR (ATR) v_max= 3061 (w), 3026 (w), 2965 (w), 2929

(m), 750 (m), 693 (s) cm⁻¹. MS (ESI+) m/z = 372 ([M + H]⁺). (w), 2872 (w), 1662 (s), 1506 (s), 1392 (m) 1252 (vs), 1198 (vs),

HRMS (ESI+) m/z calcd for C₂₅H₂₅NO₂Na 394.1783 ([M + Na]⁺), 1160 (vs), 967 (m), 858 (m), 749 (s), 694 (s) cm⁻¹. MS (EI) m/z =

found 394.1778.

363 ([M]⁺). HRMS (EI) m/z calcd for C₂₀H₂₀O₂NF₃363.1441

(E)-N-(4-Methoxyphenyl)-N-(2-methyl-4-phenylbut-3-en-1-yl)- ([M]⁺), found 363.1449. 63b: R_f= 0.20 (PE–MTBE, 1 : 1). ¹H

acetamide (62a)^7hand (E)-N-(4-methoxyphenyl)-N-(5-phenyl- NMR (500 MHz, CDCl₃) δ = 7.30–7.26 (m, 5H), 7.23–7.17 (m,

pent-4-en-1-yl)acetamide (62b).^7hGeneral procedure C was 4H), 6.34 (d, J = 15.9 Hz, 1H), 6.15 (dt, J = 15.7, 6.8 Hz, 1H),

used to synthesize 62a and 62b from para-methoxy-N-methyl- 3.78–3.71 (m, 2H), 2.25–2.18 (m, 2H), 1.84 (s, 3H), 1.70 (pent,

aniline (55, 274 mg, 2.0 mmol) and (E)-1-phenyl-1,3-butadiene J = 7.5 Hz, 2H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 170.0 (C),

(49, 391 mg, 3.0 mmol). Purification by flash column chrom- 148.4 (C), 141.7 (C), 137.5 (C), 130.5 (CH), 129.6 (CH), 129.4

atography (PE–MTBE, 2 : 1) gave three fractions as oils. Frac- (CH), 128.5 (CH), 127.0 (CH), 126.0 (CH), 122.1 (CH), 120.4 (q,

tion 1 contained pure compound 62a (82 mg, 0.27 mmol, ¹J_C,F= 258.0 Hz, CF₃), 48.8 (CH₂), 30.3 (CH₂), 27.5 (CH₂), 22.8

13%) and fraction 2 contained a mixture of 62a and 62b (CH₃) ppm. ¹⁹F NMR (500 MHz, CDCl₃) δ = −58.0 ppm. IR

(142 mg, 0.46 mmol, 23%). Fraction 3 contained pure com- (ATR) v_max= 3063 (w), 3027 (w), 2931 (w), 2866 (w), 1660 (s),

pound 62b (59 mg, 0.19 mmol, 10%). Prior to acetylation and 1506 (s), 1448 (m), 1396 (m), 1252 (vs), 1203 (vs), 1161 (vs), 967

chromatography, the ratio of the branched and the linear (m), 857 (m), 747 (m), 695 (m) cm⁻¹. MS (EI) m/z = 363 ([M]⁺).

product was determined to be 54 : 46. 62a: R_f= 0.24 (PE– HRMS (EI) m/z calcd for C₂₀H₂₀O₂NF₃363.1441 ([M]⁺), found

MTBE, 2 : 1). ¹H NMR (500 MHz, CDCl₃) δ = 7.30–7.24 (m, 4H), 363.1444.

7.19–7.15 (m, 1H), 7.05 (br. d, J = 8.8 Hz, 2H), 6.86 (br. d, J =

(E)-N-(2-Methyl-4-phenylbut-3-en-1-yl)-N-(4-(methylthio)-phenyl)-

8.8 Hz, 2H), 6.34 (d, J = 15.9 Hz, 1H), 6.04 (dd, J = 15.8, 8.4 Hz, acetamide (64a) and (E)-N-(4-(methylthio)phenyl)-N-(5-phenyl-

1H), 3.79 (s, 3H), 3.73 (dd, J = 13.4, 8.4 Hz, 1H), 3.66 (dd, J = pent-4-en-1-yl)acetamide (64b). General procedure C was used

13.4, 6.5 Hz, 1H), 2.62–2.54 (m, 1H), 1.77 (s, 3H), 1.05 (d, J = to synthesize 64a and 64b from para-thiomethyl-N-methylani-

6.8 Hz, 3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 170.9 (C), line (57, 306 mg, 2.0 mmol) and (E)-1-phenyl-1,3-butadiene

158.7 (C), 137.5 (C), 136.1 (C), 133.9 (CH), 129.8 (CH), 129.2 (49, 391 mg, 3.0 mmol). Purification by flash column chrom-

(CH), 128.4 (CH), 127.0 (CH), 126.1 (CH), 114.6 (CH), 55.4 atography (PE–MTBE, 1.5 : 1) gave three fractions as oils. Frac-

(CH₃), 54.5 (CH₂), 36.5 (CH), 22.7 (CH₃), 18.3 (CH₃) ppm. 62b: tion 1 contained pure compound 64a (123 mg, 0.38 mmol,

R_f= 0.21 (PE–MTBE, 2 : 1). ¹H NMR (500 MHz, CDCl₃) δ = 19%) and fraction 2 contained a mixture of 64a and 64b

7.32–7.24 (m, 4H), 7.19–7.15 (m, 1H), 7.08 (br. d, J = 8.9 Hz, (149 mg, 0.46 mmol, 23%). Fraction 3 contained pure com-

2H), 6.92 (br. d, J = 8.9 Hz, 2H), 6.33 (d, J = 15.8 Hz, 1H), 6.16 pound 64b (73 mg, 0.23 mmol, 11%). Prior to acetylation and

(dt, J = 15.8, 6.9 Hz, 1H), 3.83 (s, 3H), 3.73–3.69 (m, 2H), 2.21 chromatography, the ratio of the branched and the linear

1

(q, J = 7.6 Hz, 2H), 1.82 (s, 3H), 1.68 (pent, J = 7.6 Hz, 2H) product was determined to be 54 : 46. 64a: H NMR (500 MHz,

ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 170.6 (C), 158.9 (C), 137.6 CDCl₃) δ = 7.31–7.28 (m, 4H), 7.23 (br. d, J = 8.5 Hz, 2H),

(C), 135.8 (C), 130.2 (CH), 129.7 (CH), 129.1 (CH), 128.4 (CH), 7.21–7.18 (m, 1H), 7.07 (br. d, J = 8.5 Hz, 2H), 6.35 (d, J = 15.8

126.9 (CH), 125.9 (CH), 114.7 (CH), 55.4 (CH₃), 48.7 (CH₂), 30.3 Hz, 1H), 6.04 (dd, J = 15.9, 8.5 Hz, 1H), 3.76 (dd, J = 13.4, 8.8

(CH₂), 27.4 (CH₂), 22.8 (CH₃) ppm.

Hz, 1H), 3.70 (dd, J = 13.4, 6.5 Hz, 1H), 2.64–2.57 (m, 1H), 2.49

(E)-N-(2-Methyl-4-phenylbut-3-en-1-yl)-N-(4-(trifluoromethoxy)- (s, 3H), 1.81 (s, 3H), 1.07 (d, J = 6.8 Hz, 3H) ppm. ¹³C NMR

phenyl)acetamide (63a) and (E)-N-(5-phenylpent-4-en-1-yl)-N-(4- (125 MHz, CDCl₃) δ = 170.6 (C), 140.2 (C), 138.4 (C), 137.4 (C),

(trifluoromethoxy)phenyl)-acetamide (63b). General procedure 133.8 (CH), 129.9 (CH), 128.6 (CH), 128.5 (CH), 127.1 (CH),

C was used to synthesize 63a and 63b from para-trifluoro- 126.1 (CH), 54.4 (CH₂), 36.6 (CH), 22.8 (CH₃), 18.4 (CH₃), 15.6

methoxy-N-methylaniline (56, 382 mg, 2.0 mmol), and (E)-1- (CH₃) ppm. IR (ATR) v_max= 3025 (w), 2963 (w), 2921 (m), 2851

phenyl-1,3-butadiene (49, 391 mg, 3.0 mmol). Purification by (w), 1656 (vs), 1492 (vs), 1391 (s), 1286 (m), 1098 (m), 966 (s),

flash column chromatography (PE–MTBE, 1 : 1) gave three frac- 829 (m), 747 (s), 694 (s) cm⁻¹. MS (ESI+) m/z = 348 ([M + Na]⁺).

tions as oils. Fraction 1 contained pure compound 63a (76 mg, HRMS (ESI+) m/z calcd for C₂₀H₂₃NOSNa 348.1398 ([M + Na]⁺),

1

0.21 mmol, 11%) and fraction 2 contained a mixture of 63a found 348.1401. 64b: H NMR (500 MHz, CDCl₃) δ = 7.24–7.18

and 63b (412 mg, 1.14 mmol, 57%). Fraction 3 contained pure (m, 6H), 7.13–7.09 (m, 1H), 7.01 (br. d, J = 8.4 Hz, 2H), 6.25

Dalton Trans., 2015, 44, 12149–12168 | 12163

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(d, J = 15.7 Hz, 1H), 6.08 (dt, J = 15.8, 6.9 Hz, 1H), 3.68–3.62 graphy (PE–MTBE, 1 : 1) gave three fractions as oils. Fraction 1

(m, 2H), 2.43 (s, 3H), 2.17–2.11 (m, 2H), 1.77 (s, 3H), 1.61 contained pure compound 66a (111 mg, 0.36 mmol, 18%) and

(pent, J = 7.6 Hz, 2H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = fraction 2 contained a mixture of 66a and 66b (206 mg,

170.3 (C), 139.9 (C), 138.6 (C), 137.5 (C), 130.3 (CH), 129.6 0.66 mmol, 33%). Fraction 3 contained compound 66b (88 mg,

(CH), 128.5 (CH), 128.4 (CH), 127.2 (CH), 126.9 (CH), 125.9 0.28 mmol, 14%) with trace impurities of 66a. Prior to acetyl-

(CH), 48.6 (CH₂), 30.3 (CH₂), 27.4 (CH₂), 22.8 (CH₃), 15.6 (CH₃) ation and chromatography, the ratio of the branched and the

ppm. IR (ATR) v_max= 3024 (w), 2920 (m), 2851 (w), 1654 (vs), linear product was determined to be 50 : 50. 66a: R_f= 0.23 (PE–

1492 (s), 1438 (m), 1392 (s), 1291 (m), 1098 (m), 966 (s), 828 MTBE, 1 : 1). ¹H NMR (500 MHz, CDCl₃) δ = 7.36 (d, J = 8.6 Hz,

(m), 747 (m), 693 (s) cm⁻¹. MS (ESI+) m/z = 348 ([M + Na]⁺). 2H), 7.32–7.28 (m, 4H), 7.24–7.19 (m, 1H), 7.10 (d, J = 8.5 Hz,

HRMS (ESI+) m/z calcd for C₂₀H₂₃NOSNa 348.1398 ([M + Na]⁺), 2H), 6.35 (d, J = 15.9 Hz, 1H), 6.02 (dd, J = 15.8, 8.6 Hz, 1H),

found 348.1397.

3.76 (dd, J = 13.5, 9.0 Hz, 1H), 3.70 (dd, J = 13.5, 6.4 Hz, 1H),

(E)-N-(4-Isopropylphenyl)-N-(2-methyl-4-phenylbut-3-en-1-yl)- 2.65–2.56 (m, 1H), 1.81 (s, 3H), 1.07 (d, J = 6.7 Hz, 3H) ppm.

acetamide (65a) and (E)-N-(4-isopropylphenyl)-N-(5-phenyl- ¹³C NMR (125 MHz, CDCl₃) δ = 170.3 (C), 141.9 (C), 137.3 (C),

pent-4-en-1-yl)acetamide (65b). General procedure C was used 133.6 (CH), 133.5 (C), 130.1 (CH), 129.8 (CH), 129.6 (CH), 128.5

to synthesize 65a and 65b from para-isopropyl-N-methylaniline (CH), 127.2 (CH), 126.1 (CH), 54.5 (CH₂), 36.6 (CH), 22.8 (CH₃),

(58, 299 mg, 2.0 mmol) and (E)-1-phenyl-1,3-butadiene (49, 18.4 (CH₃) ppm. 66b: R_f= 0.19 (PE–MTBE, 1 : 1). ¹H NMR

391 mg, 3.0 mmol). Purification by flash column chromato- (500 MHz, CDCl₃) δ = 7.36 (d, J = 8.6 Hz, 2H), 7.28–7.21 (m,

graphy (PE–MTBE, 1.5 : 1) gave three fractions as oils. Fraction 4H), 7.16–7.12 (m, 1H), 7.07 (d, J = 8.6 Hz, 2H), 6.29 (d, J = 15.8

1 contained pure compound 65a (74 mg, 0.23 mmol, 12%) and Hz, 1H), 6.10 (dt, J = 15.7, 6.9 Hz, 1H), 3.71–3.66 (m, 2H),

fraction 2 contained a mixture of 65a and 65b (278 mg, 2.20–2.14 (m, 2H), 1.80 (s, 3H), 1.63 (pent, J = 7.6 Hz, 2H)

0.87 mmol, 43%). Fraction 3 contained pure compound 65b ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 170.0 (C), 141.6 (C), 137.5

(61 mg, 0.19 mmol, 9%). Prior to acetylation and chromato- (C), 133.7 (C), 130.4 (CH), 129.9 (CH), 129.4 (CH), 128.4 (CH),

graphy, the ratio of the branched and the linear product was 126.9 (CH), 125.9 (CH), 48.7 (CH₂), 30.2 (CH₂), 27.4 (CH₂), 22.8

1

determined to be 53 : 47. 65a: H NMR (500 MHz, CDCl₃) δ = (CH₃) ppm. IR (ATR) v_max= 3059 (w), 3025 (w), 2929 (m), 2864

7.31–7.27 (m, 4H), 7.22 (d, J = 8.3 Hz, 2H), 7.21–7.18 (m, 1H), (w), 1657 (vs), 1489 (vs), 1446 (m), 1392 (s), 1289 (m), 1091 (s),

7.07 (d, J = 8.3 Hz, 2H), 6.36 (d, J = 15.9 Hz, 1H), 6.06 (dd, J = 1014 (m), 966 (s), 838 (m), 746 (s) 693 (s) cm⁻¹. MS (ESI+) m/z =

15.8, 8.4 Hz, 1H), 3.77 (dd, J = 13.4, 8.7 Hz, 1H), 3.71 (dd, J = 336 ([M + Na]⁺). HRMS (ESI+) m/z calcd for C₁₉H₂₀NOClNa

13.4, 6.5 Hz, 1H), 2.93 (hept, J = 6.9 Hz, 1H), 2.67–2.58 (m, 336.1131 ([M + Na]⁺), found 336.1130.

1H), 1.81 (s, 3H), 1.26 (d, J = 6.9 Hz, 6H), 1.08 (d, J = 6.8 Hz,

(E)-N-(4-(4-Chlorophenyl)-2-methylbut-3-en-1-yl)-N-phenyl-

3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 170.8 (C), 148.4 (C), acetamide (67a) and (E)-N-(5-(4-chlorophenyl)pent-4-en-1-yl)-

140.9 (C), 137.6 (C), 134.0 (CH), 129.7 (CH), 128.4 (CH), 128.0 N-phenylacetamide (67b).^7hGeneral procedure C was used to

(CH), 127.4 (CH), 127.0 (CH), 126.1 (CH), 54.4 (CH₂), 36.5 synthesize 67a and 67b from N-methylaniline (2, 214 mg,

(CH), 33.7 (CH), 23.9 (CH₃), 22.9 (CH₃), 18.3 (CH₃) ppm. IR 2.0 mmol) and (E)-1-(para-chlorophenyl)-1,3-butadiene (50,

(ATR) v_max= 3027 (w), 2963 (m), 2929 (w), 2872 (w), 1658 (vs), 494 mg, 3.0 mmol). Purification by flash column chromato-

1511 (s), 1395 (s), 1289 (m), 1215 (w), 968 (m), 845 (m), 749 (s), graphy (PE–MTBE, 2 : 1) gave three fractions as oils. Fraction 1

696 (s) cm⁻¹. MS (ESI+) m/z = 344 ([M + Na]⁺). HRMS (ESI+) m/z contained pure compound 67a (65 mg, 0.21 mmol, 10%) and

calcd for C₂₂H₂₇NONa 344.1990 ([M + Na]⁺), found 344.1982. fraction 2 contained a mixture of 67a and 67b (150 mg,

1

65b: H NMR (500 MHz, CDCl₃) δ = 7.31–7.24 (m, 7H), 7.07 (d, 0.48 mmol, 25%). Fraction 3 contained pure compound 67b

J = 8.3 Hz, 2H), 6.33 (d, J = 15.9 Hz, 1H), 6.16 (dt, J = 15.8, 6.8 (109 mg, 0.35 mmol, 17%). Prior to acetylation and chromato-

Hz, 1H), 3.75–3.71 (m, 2H), 2.94 (hept, J = 7.0 Hz, 1H), graphy, the ratio of the branched and the linear product was

2.24–2.18 (m, 2H), 1.83 (s, 3H), 1.70 (pent, J = 7.6 Hz, 2H), 1.27 determined to be 50 : 50. 67a: R_f= 0.19 (PE–MTBE, 2 : 1). ¹H

(d, J = 6.9 Hz, 6H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 170.5 NMR (500 MHz, CDCl₃) δ = 7.38 (t, J = 7.6 Hz, 2H), 7.32 (t, J =

(C), 148.6 (C), 140.7 (C), 137.6 (C), 130.2 (CH), 129.8 (CH), 7.4 Hz, 1H), 7.25–7.19 (m, 4H), 7.14 (d, J = 7.7 Hz, 2H), 6.31 (d,

128.4 (CH), 127.8 (CH), 127.6 (CH), 126.9 (CH), 125.9 (CH), J = 15.9 Hz, 1H), 6.03 (dd, J = 15.8, 8.4 Hz, 1H), 3.79 (dd, J =

48.7 (CH₂), 33.7 (CH), 30.3 (CH₂), 27.4 (CH₂), 23.9 (CH₃), 22.8 13.5, 8.8 Hz, 1H), 3.70 (dd, J = 13.4, 6.4 Hz, 1H), 2.66–2.56 (m,

(CH₃) ppm. IR (ATR) v_max= 3028 (w), 2962 (m), 2930 (w), 2872 1H), 1.80 (s, 3H), 1.07 (d, J = 6.8 Hz, 3H) ppm. ¹³C NMR

(w), 1658 (vs), 1511 (s), 1397 (s), 1294 (m), 968 (m), 845 (m), (125 MHz, CDCl₃) δ = 170.6 (C), 143.3 (C), 135.9 (C), 134.6

749 (m), 696 (s) cm⁻¹. MS (ESI+) m/z = 344 ([M + Na]⁺). HRMS (CH), 132.6 (C), 129.6 (CH), 128.6 (CH), 128.5 (CH), 128.2 (CH),

(ESI+) m/z calcd for C₂₂H₂₈NO 322.2165 ([M + H]⁺), found 127.7 (CH), 127.3 (CH), 54.4 (CH₂), 36.6 (CH), 22.8 (CH₃), 18.3

322.2168.

(CH₃) ppm. IR (ATR) v_max= 3028 (w), 2965 (w), 2926 (m), 2871

(E)-N-(4-Chlorophenyl)-N-(2-methyl-4-phenylbut-3-en-1-yl)- (w), 1655 (vs), 1594 (s), 1491 (s), 1394 (s), 1291 (s), 1276 (s),

acetamide (66a)^7hand (E)-N-(4-chlorophenyl)-N-(5-phenylpent- 1089 (s), 967 (m), 806 (m), 776 (m), 700 (s) cm⁻¹. MS (ESI+) m/z

4-en-1-yl)acetamide (66b). General procedure C was used to = 314 ([M + H]⁺). HRMS (ESI+) m/z calcd for C₁₉H₂₀NOClNa

synthesize 66a and 66b from para-chloro-N-methylaniline (59, 336.1131 ([M + Na]⁺), found 336.1122. 67b: R_f= 0.10 (PE–

1

283 mg, 2.0 mmol) and (E)-1-phenyl-1,3-butadiene (49, MTBE, 2 : 1). H NMR (500 MHz, CDCl₃) δ = 7.42 (t, J = 7.6 Hz,

391 mg, 3.0 mmol). Purification by flash column chromato- 2H), 7.35 (t, J = 7.4 Hz, 1H), 7.23–7.19 (m, 4H), 7.16 (d, J =

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7.5 Hz, 2H), 6.27 (d, J = 15.9 Hz, 1H), 6.13 (dt, J = 15.8, 6.8 Hz, aniline (2, 214 mg, 2.0 mmol) and (E)-1,3-decadiene (52,

1H), 3.77–3.72 (m, 2H), 2.20 (q, J = 7.0 Hz, 2H), 1.83 (s, 3H), 415 mg, 3.0 mmol). Purification by flash column chromato-

1.68 (pent, J = 7.5 Hz, 2H) ppm. ¹³C NMR (125 MHz, CDCl₃) graphy (PE–MTBE, 2 : 1) gave three fractions as oils. Fraction 1

δ = 170.3 (C), 143.0 (C), 136.0 (C), 132.3 (C), 130.4 (CH), 129.7 contained compound 69a and a derivative with isomerized

(CH), 129.1 (CH), 128.5 (CH), 128.0 (CH), 127.8 (CH), 127.1 double bond (526 mg, 1.83 mmol, 46%). Fraction 2 contained

(CH), 48.6 (CH₂), 30.2 (CH₂), 27.3 (CH₂), 22.7 (CH₃) ppm. IR compound 69a, its isomerized derivative as well as compound

(ATR) v_max= 3026 (w), 2924 (m), 2850 (w), 1652 (vs), 1595 (m), 69b (143 mg, 0.50 mmol, 12%). Fraction 3 contained com-

1491 (s), 1396 (s), 1294 (m), 1089 (m), 967 (m), 775 (m), 700 pound 69b (112 mg, 0.39 mmol, 10%) with trace impurities of

(vs) cm⁻¹. MS (ESI+) m/z = 336 ([M + Na]⁺). HRMS (ESI+) m/z 69a. Prior to acetylation and chromatography, the ratio of the

calcd for C₁₉H₂₀NOClNa 336.1131 ([M + Na]⁺), found 336.1124. branched, the branched isomerized, and the linear product

(E)-N-(4-(4-Fluorophenyl)-2-methylbut-3-en-1-yl)-N-phenyl- was determined to be 50 : 27 : 23. 69a: ¹H NMR (500 MHz,

acetamide (68a) and (E)-N-(5-(4-fluorophenyl)pent-4-en-1-yl)- CDCl₃) δ = 7.44–7.37 (m, 2H), 7.35–7.29 (m, 1H), 7.16 (d, J = 7.5

N-phenylacetamide (68b). General procedure C was used to Hz, 2H), 5.43–5.33 (m, 1H), 5.26 (dd, J = 15.4, 8.0 Hz, 1H), 3.66

synthesize 68a and 68b from N-methylaniline (2, 214 mg, (dd, J = 13.5, 8.4 Hz, 1H), 3.59 (dd, J = 13.3, 6.9 Hz, 1H), 2.33

2.0 mmol) and (E)-1-(para-fluorophenyl)-1,3-butadiene (51, (hept, J = 7.3 Hz, 1H), 2.95 (q, J = 7.0 Hz, 2H), 1.81 (s, 3H),

445 mg, 3.0 mmol). Purification by flash column chromato- 1.35–2.26 (m, 8H), 0.95 (d, J = 6.8 Hz, 3H), 0.87 (t, J = 6.8 Hz,

graphy (PE–MTBE, 2 : 1) gave three fractions as oils. Fraction 1 3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 170.5 (C), 143.4 (C),

contained pure compound 68a (100 mg, 0.34 mmol, 18%) and 133.2 (CH), 130.7 (CH), 129.5 (CH), 128.2 (CH), 127.6 (CH),

fraction 2 contained a mixture of 68a and 68b (151 mg, 54.4 (CH₂), 35.7 (CH), 32.5 (CH₂), 31.7 (CH₂), 29.5 (CH₂), 28.8

0.51 mmol, 25%). Fraction 3 contained pure compound 68b (CH₂), 22.9 (CH₃), 22.6 (CH₂), 14.1 (CH₃) ppm. IR (ATR) v_max

=

(62 mg, 0.21 mmol, 10%). Prior to acetylation and chromato- 2957 (m), 2925 (m), 2855 (m), 1661 (vs), 1595 (m), 1495 (m),

graphy, the ratio of the branched and the linear product was 1393 (s), 1276 (m), 1217 (w), 1073 (w), 968 (m), 776 (w), 700

determined to be 50 : 50. 68a: R_f= 0.19 (PE–MTBE, 2 : 1). ¹H (vs). MS (ESI+) m/z = 310 ([M + Na]⁺). HRMS (ESI+) m/z calcd

NMR (500 MHz, CDCl₃) δ = 7.31 (t, J = 7.5 Hz, 2H), 7.25 (t, J = for C₁₉H₂₉NONa 310.2147 ([M + Na]⁺), found 310.2145. 69b: ¹H

7.4 Hz, 1H), 7.19–7.15 (m, 2H), 7.08 (d, J = 7.4 Hz, 2H), 6.89 (t, NMR (500 MHz, CDCl₃) δ = 7.39 (t, J = 7.7 Hz, 2H), 7.32 (t, J =

J = 8.7 Hz, 2H), 6.25 (d, J = 15.9 Hz, 1H), 5.89 (dd, J = 15.9, 8.5 7.3 Hz, 1H), 7.14 (d, J = 8.0 Hz, 2H), 5.36–5.26 (m, 2H),

Hz, 1H), 3.72 (dd, J = 13.4, 8.9 Hz, 1H), 3.63 (dd, J = 13.4, 6.4 3.69–3.64 (m, 2H), 1.95 (q, J = 7.0 Hz, 2H), 1.91 (q, J = 6.2 Hz,

Hz, 1H), 2.57–2.49 (m, 1H), 1.73 (s, 3H), 0.99 (d, J = 6.8 Hz, 3H) 2H), 1.80 (s, 3H), 1.55 (pent, J = 7.5 Hz, 2H), 1.30–1.19 (m, 8H),

ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 170.6 (C), 161.9 (d, ¹J_C,F

=

0.85 (t, J = 6.7 Hz, 3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ =

246.0 Hz, C), 143.3 (C), 133.6 (CH), 129.5 (CH), 128.6 (CH), 170.1 (C), 143.2 (C), 131.1 (CH), 129.6 (CH), 128.9 (CH), 128.1

3

128.2 (CH), 127.7 (CH), 127.5 (d, J_C,F= 7.9 Hz, CH), 115.3 (d, (CH), 127.7 (CH), 48.7 (CH₂), 32.5 (CH₂), 31.7 (CH₂), 29.8

²J_C,F= 21.4 Hz, CH), 54.4 (CH₂), 36.5 (CH), 22.8 (CH₃), 18.3 (CH₂), 29.4 (CH₂), 28.7 (CH₂), 27.6 (CH₂), 22.8 (CH₃), 22.6

(CH₃) ppm. ¹⁹F NMR (500 MHz, CDCl₃) δ = −115.4 ppm. IR (CH₂), 14.0 (CH₃) ppm. IR (ATR) v_max= 2955 (w), 2924 (m),

(ATR) v_max= 3038 (w), 2967 (w), 2927 (w), 2871 (w), 1655 (vs), 2854 (m), 1659 (vs), 1596 (m), 1405 (m), 1394 (s), 1294 (m), 967

1594 (m), 1507 (m), 1495 (m), 1395 (m), 1293 (m), 1277 (m), (m), 774 (w), 700 (vs). MS (ESI+) m/z = 310 ([M + Na]⁺). HRMS

1224 (s), 1158 (m), 967 (m), 849 (m), 813 (m), 772 (m), 700 (s) (ESI+) m/z calcd for C₁₉H₂₉NONa 310.2147 ([M + Na]⁺), found

cm⁻¹. MS (ESI+) m/z = 298 ([M + H]⁺). HRMS (ESI+) m/z calcd 310.2143.

for C₁₉H₂₁FNO 298.1607 ([M + H]⁺), found 298.1606. 68b: R_f=

(E)-N-(2-Methyl-6-phenylhex-3-en-1-yl)aniline (70a)^7hand

1

0.12 (PE–MTBE, 2 : 1). H NMR (500 MHz, CDCl₃) δ = 7.34 (t, (E)-N-(7-phenylhept-4-en-1-yl)aniline (70b). General procedure

J = 7.6 Hz, 2H), 7.27 (t, J = 7.4 Hz, 1H), 7.19–7.14 (m, 2H), 7.09 C was used without the acetylation step to synthesize 70a and

(d, J = 7.9 Hz, 2H), 6.87 (t, J = 8.7 Hz, 2H), 6.21 (d, J = 15.9 Hz, 70b from N-methylaniline (2, 214 mg, 2.0 mmol) and (E)-6-phe-

1H), 5.99 (dt, J = 15.9, 6.9 Hz, 1H), 3.69–3.64 (m, 2H), 2.12 (q, nylhexa-1,3-diene (53, 475 mg, 3.0 mmol). Purification by flash

J = 7.4 Hz, 2H), 1.76 (s, 3H), 1.61 (pent, J = 7.5 Hz, 2H) ppm. column chromatography (PE–MTBE, 70 : 1) gave three fractions

¹³C NMR (125 MHz, CDCl₃) δ = 170.2 (C), 161.8 (d, ¹J_C,F= 245.7 as oils. Fraction 1 contained compound 70a and its double

4

Hz, C), 143.1 (C), 133.7 (d, J_C,F= 3.3 Hz, C), 129.7 (CH), 129.4 bond isomer (E)-N-(2-methyl-6-phenylhex-4-en-1-yl)aniline

3

(CH), 129.1 (CH), 128.1 (CH), 127.8 (CH), 127.3 (d, J_C,F= 7.9 (301 mg, 1.13 mmol, 57%) in a ratio of 2 : 1 and fraction 2 con-

2

Hz, CH), 115.2 (d, J_C,F= 21.4 Hz, CH), 48.6 (CH₂), 30.2 (CH₂), tained a mixture of 70a and 70b (88 mg, 0.33 mmol, 17%).

27.4 (CH₂), 22.8 (CH₃) ppm. ¹⁹F NMR (500 MHz, CDCl₃) δ = Fraction 3 contained pure compound 70b (72 mg, 0.27 mmol,

−115.7 ppm. IR (ATR) v_max= 3038 (w), 2926 (m), 2853 (w), 1652 13%). Prior to chromatography, the ratio of the branched

(vs), 1595 (s), 1506 (s), 1495 (s), 1395 (s), 1224 (s), 967 (m), 838 (70a), the branched isomerized, and the linear product (70b)

(m), 770 (m), 700 (vs) cm⁻¹. MS (ESI+) m/z = 298 ([M + H]⁺). was determined to be 47 : 28 : 25. 70a: R_f= 0.24 (PE–MTBE,

HRMS (ESI+) m/z calcd for C₁₉H₂₁NOF 298.1607 ([M + H]⁺), 70 : 1). ¹H NMR (500 MHz, CDCl₃) δ = 7.31–7.26 (m, 2H),

found 298.1602.

7.23–7.15 (m, 5H), 6.70 (t, J = 7.3 Hz, 1H), 6.62–6.55 (m, 2H),

(E)-N-(2-Methyldec-3-en-1-yl)-N-phenylacetamide (69a) and 5.57–5.50 (m, 1H), 5.30 (dd, J = 15.4, 8.0 Hz, 1H), 3.66 (br. s,

(E)-N-phenyl-N-(undec-4-en-1-yl)acetamide (69b). General pro- 1H), 3.06 (dd, J = 11.9, 5.4 Hz, 1H), 2.84 (dd, J = 11.8, 8.5 Hz,

cedure C was used to synthesize 69a and 69b from N-methyl- 1H), 2.71 (t, J = 7.5 Hz, 2H), 2.37 (m, 2H), 1.05 (d, J = 6.8 Hz,

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3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 148.3 (C), 141.8 (C), 69a and the derivative with isomerized double bond (350 mg,

134.3 (CH), 130.3 (CH), 129.2 (CH), 128.5 (CH), 128.3 (CH), 1.22 mmol), Pd/C (17 mg, 5 wt%) and dry methanol (20 mL).

125.8 (CH), 117.1 (CH), 112.9 (CH), 49.6 (CH₂), 36.7 (CH), 35.9 Then the argon atmosphere was purged with hydrogen gas

(CH₂), 34.3 (CH₂), 18.1 (CH₃) ppm. 70b: R_f= 0.23 (PE–MTBE, and the reaction mixture was stirred for 2 h at room tempera-

1

70 : 1). H NMR (500 MHz, CDCl₃) δ = 7.29 (t, J = 7.5 Hz, 2H), ture. After the starting materials had been completely con-

7.23–7.16 (m, 5H), 6.71 (t, J = 7.3 Hz, 1H), 6.61 (d, J = 7.7 Hz, sumed (monitored by TLC), the solvent was removed under

2H), 5.56–5.42 (m, 2H), 3.63 (br. s, 1H), 3.10 (t, J = 7.1 Hz, 2H), reduced pressure in the presence of Celite®. After purification

2.73–2.66 (m, 2H), 2.34 (q, J = 7.4 Hz, 2H), 2.11 (q, J = 7.0 Hz, by flash column chromatography (SiO₂, PE–MTBE, 5 : 1), com-

2H), 1.68 (pent, J = 7.2 Hz, 2H) ppm. ¹³C NMR (125 MHz, pound 72 (301 mg, 1.04 mmol, 85%) was isolated as a colorless

1

CDCl₃) δ = 148.4 (C), 142.0 (C), 130.2 (CH), 130.0 (CH), 129.2 oil. 72: H NMR (500 MHz, CDCl₃) δ = 7.41 (t, J = 7.7 Hz, 2H),

(CH), 128.4 (CH), 128.2 (CH), 125.7 (CH), 117.1 (CH), 112.7 7.33 (t, J = 7.3 Hz, 1H), 7.16 (d, J = 7.5 Hz, 2H), 3.65 (dd, J =

(CH), 43.3 (CH₂), 36.0 (CH₂), 34.4 (CH₂), 30.0 (CH₂), 29.2 (CH₂) 13.2, 8.2 Hz, 1H), 3.54 (dd, J = 13.4, 6.7 Hz, 1H), 1.83 (s, 3H),

ppm. IR (ATR) v_max= 3412 (w), 3052 (w), 3024 (w), 2925 (m), 1.60–1.51 (m, 1H), 1.32–1.11 (m, 14 H), 0.89–0.84 (m, 6H)

2852 (w), 1602 (vs), 1505 (vs), 1453 (m), 1319 (m), 1257 (m), ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 170.6 (C), 143.4 (C), 129.6

1179 (w), 968 (m), 867 (w), 745 (s), 691 (s) cm⁻¹. MS (ESI+) m/z (CH), 128.0 (CH), 127.6 (CH), 54.7 (CH₂), 34.2 (CH₂), 31.9

= 266 ([M + H]⁺). HRMS (ESI+) m/z calcd for C₁₉H₂₄N 266.1909 (CH₂), 31.5 (CH), 29.8 (CH₂), 29.5 (CH₂), 29.3 (CH₂), 26.8

([M + H]⁺), found 266.1901.

(CH₂), 22.9 (CH₃), 22.6 (CH₂), 17.3 (CH₃), 14.1 (CH₃) ppm. IR

(E)-N-(2,3-Dimethyl-4-phenylbut-3-en-1-yl)-N-phenylacetamide (ATR) v_max= 2956 (m), 2924 (s), 2854 (m), 1662 (vs), 1595 (m),

(71a) and (E)-N-(4-methyl-5-phenylpent-4-en-1-yl)-N-phenylaceta- 1495 (m), 1455 (m), 1395 (s), 1290 (m), 1276 (m), 776 (w), 700

mide (71b). General procedure C was used to synthesize 71a (s) cm⁻¹. MS (ESI+) m/z = 312 ([M + Na]⁺). HRMS (ESI+) m/z

and 71b from N-methylaniline (2, 214 mg, 2.0 mmol) and (E)- calcd for C₁₉H₃₁NONa 312.2303 ([M + Na]⁺), found 312.2294.

2-methyl-1-phenyl-1,3-butadiene (54, 433 mg, 3.0 mmol). Puri-

para-Toluenesulfonamide 76b. General procedure D was

fication by flash column chromatography (PE–MTBE, 2 : 1) used to synthesize 76b from N-methylbenzylamine (38,

gave three fractions as oils. Fraction 1 contained pure com- 242 mg, 2.0 mmol) and (E)-1-phenyl-1,3-butadiene (49,

pound 71a (159 mg, 0.54 mmol, 27%) and fraction 2 contained 391 mg, 3.0 mmol). Purification by flash column chromato-

a mixture of 71a and 71b (236 mg, 0.81 mmol, 41%). Fraction graphy (PE–MTBE, 12 : 1) gave one fraction (504 mg) as an oil

1

3 contained pure compound 71b (30 mg, 0.10 mmol, 5%). of high viscosity. According to H NMR spectroscopy, the frac-

Prior to acetylation and chromatography, the ratio of the tion contained a mixture of 76b (466 mg, 1.15 mmol, 58%)

branched and the linear product was determined to be 51 : 49. and tosylated N-methylbenzylamine (35 mg, 0.13 mmol). Prior

1

71a: R_f= 0.26 (PE–MTBE, 2 : 1). H NMR (500 MHz, CDCl₃) δ = to tosylation and chromatography, the ratio of the branched

7.40–7.36 (m, 2H), 7.33–7.28 (m, 3H), 7.23–7.16 (m, 5H), 6.30 and the linear product was determined to be 7 : 93. 76b: R_f=

1

(s, 1H), 3.87 (dd, J = 13.6, 9.1 Hz, 1H), 3.79 (dd, J = 13.6, 6.1 0.25 (PE–MTBE, 12 : 1). H NMR (300 MHz, CDCl₃) δ = 7.62 (d,

Hz, 1H), 2.66–2.57 (m, 1H), 1.83 (s, 3H), 1.68 (s, 3H), 1.08 (d, J = 8.3 Hz, 2H), 7.31–7.16 (m, 12H), 6.27 (d, J = 15.8 Hz, 1H),

J = 7.0 Hz, 3H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 170.3 (C), 6.13 (dt, J = 15.8, 6.4 Hz, 1H), 5.11 (t, J = 7.3 Hz, 1H), 2.62 (s,

143.1 (C), 140.4 (C), 138.0 (C), 129.3 (CH), 128.7 (CH), 128.1 3H), 2.37 (s, 3H), 2.18–1.99 (m, 3H), 1.88–1.75 (m, 1H) ppm.

(CH), 127.9 (CH), 127.5 (CH), 126.0 (CH), 125.9 (CH), 52.7 ¹³C NMR (75 MHz, CDCl₃) δ = 143.0 (C), 138.0 (C), 137.5 (C),

(CH₂), 42.1 (CH), 22.7 (CH₃), 17.1 (CH₃), 13.7 (CH₃) ppm. IR 137.2 (C), 130.7 (CH), 129.5 (CH), 129.1 (CH), 128.5 (CH), 128.4

(ATR) v_max= 3057 (w), 3025 (w), 2967 (w), 2933 (w), 2874 (w), (CH), 128.0 (CH), 127.8 (CH), 127.2 (CH), 127.0 (CH), 125.9

1658 (vs), 1596 (m), 1496 (s), 1395 (s), 1295 (m), 1277 (m), 779 (CH), 59.5 (CH), 30.3 (CH₂), 29.9 (CH₂), 28.8 (CH₃), 21.5 (CH₃)

(m), 745 (m), 700 (vs) cm⁻¹. MS (ESI+) m/z = 316 ([M + Na]⁺). ppm. IR (ATR) v_max= 3062 (w), 3028 (w), 2941 (w), 2872 (w),

HRMS (ESI+) m/z calcd for C₂₀H₂₃NONa 316.1677 ([M + Na]⁺), 1598 (m), 1494 (m), 1452 (m), 1333 (s), 1131 (vs), 1088 (s), 933

found 316.1682. 71b: R_f= 0.17 (PE–MTBE, 2 : 1). ¹H NMR (s), 813 (m), 736 (s), 712 (vs) cm⁻¹. MS (ESI+) m/z = 428

(500 MHz, CDCl₃) δ = 7.43 (t, J = 7.6 Hz, 2H), 7.36 (t, J = 7.4 Hz, ([M + Na]⁺). HRMS (ESI+) m/z calcd for C₂₅H₂₇NO₂SNa

1H), 7.29 (t, J = 7.6 Hz, 2H), 7.21–7.15 (m, 5H), 6.21 (s, 1H), 428.1660 ([M + Na]⁺), found 428.1666.

3.77–3.71 (m, 2H), 2.20–2.14 (m, 2H), 1.85 (s, 3H), 1.80 (d, J =

para-Toluenesulfonamide 77b. General procedure D was

1.3 Hz, 3H), 1.79–1.73 (m, 2H) ppm. ¹³C NMR (125 MHz, used to synthesize 77b from N-methylbenzylamine (38,

CDCl₃) δ = 170.2 (C), 143.2 (C), 138.4 (C), 138.1 (C), 129.7 (CH), 242 mg, 2.0 mmol) and (E)-1-(para-chlorophenyl)-1,3-buta-

128.8 (CH), 128.1 (CH), 128.0 (CH), 127.8 (CH), 125.8 (CH), diene (50, 494 mg, 3.0 mmol). Purification by flash column

125.2 (CH), 48.9 (CH₂), 37.8 (CH₂), 26.1 (CH₂), 22.8 (CH₃), 17.6 chromatography (PE–MTBE, 12 : 1) gave one fraction (615 mg)

1

(CH₃) ppm. IR (ATR) v_max= 3057 (w), 3025 (w), 2932 (w), 2859 as an oil of high viscosity. According to H NMR spectroscopy,

(w), 1656 (s), 1597 (s), 1496 (s), 1397 (s), 1298 (m), 1076 (w), the fraction contained a mixture of 77b (590 mg, 1.34 mmol,

743 (m), 700 (vs) cm⁻¹. MS (ESI+) m/z = 316 ([M + Na]⁺). HRMS 67%) and tosylated N-methylbenzylamine (25 mg, 0.09 mmol).

(ESI+) m/z calcd for C₂₀H₂₃NONa 316.1677 ([M + Na]⁺), found Prior to tosylation and chromatography, the ratio of the

316.1682.

branched and the linear product was determined to be 8 : 92.

1

N-Phenyl-N-(2-methyldecyl)acetamide (72). Under an inert 77b: R_f= 0.22 (PE–MTBE, 12 : 1). H NMR (500 MHz, CDCl₃) δ

atmosphere of argon, a flask was charged with a mixture of = 7.62 (d, J = 8.4 Hz, 2H), 7.30–7.17 (m, 11H), 6.28 (d, J = 15.8

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Hz, 1H), 6.14 (dt, J = 15.8, 6.7 Hz, 1H), 5.13 (t, J = 7.6 Hz, 1H), 3062 (w), 3032 (w), 2956 (w), 2923 (m), 2853 (m), 1608 (m),

2.63 (s, 3H), 2.38 (s, 3H), 2.22–2.03 (m, 3H), 1.90–1.82 (m, 1H) 1512 (s), 1457 (m), 1335 (m), 1248 (s), 1156 (vs), 1089 (m), 1033

ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 143.0 (C), 138.0 (C), 137.2 (m), 934 (m), 809 (s), 701 (s), 660 (vs) cm⁻¹. MS (ESI+) m/z =

(C), 136.0 (C), 132.5 (C), 129.9 (CH), 129.5 (CH), 129.4 (CH), 458 ([M + Na]⁺). HRMS (ESI+) m/z calcd for C₂₆H₂₉NO₃SNa

128.6 (CH), 128.4 (CH), 128.0 (CH), 127.8 (CH), 127.1 (CH), 458.1766 ([M + Na]⁺), found 458.1758.

59.4 (CH), 30.2 (CH₂), 29.8 (CH₂), 28.7 (CH₃), 21.4 (CH₃) ppm.

para-Toluenesulfonamide 80b. General procedure D was

IR (ATR) v_max= 3064 (w), 3032 (w), 2939 (w), 1599 (m), 1493 used to synthesize 80b from N-methylbenzylamine (38,

(m), 1455 (m), 1335 (s), 1157 (vs), 1090 (s), 935 (s), 812 (s), 701 242 mg, 2.0 mmol) and (E)-1-(ortho-methylphenyl)-1,3-buta-

(s), 659 (vs) cm⁻¹. MS (ESI+) m/z = 462 ([M + Na]⁺). HRMS diene (74, 433 mg, 3.0 mmol). Purification by flash column

(ESI+) m/z calcd for C₂₅H₂₆NO₂SClNa 462.1270 ([M + Na]⁺), chromatography (PE–MTBE, 9 : 1) gave one fraction (605 mg)

1

found 462.1267.

as an oil of high viscosity. According to H NMR spectroscopy,

para-Toluenesulfonamide 78b. General procedure D was the fraction contained a mixture of 80b (575 mg, 1.37 mmol,

used to synthesize 78b from N-methylbenzylamine (38, 69%), tosylated N-methylbenzylamine (30 mg, 0.11 mmol),

242 mg, 2.0 mmol) and (E)-1-(para-fluorophenyl)-1,3-butadiene and trace amounts of the corresponding branched product.

(51, 445 mg, 3.0 mmol). Purification by flash column chrom- Prior to tosylation and chromatography, the ratio of the

atography (PE–MTBE, 12 : 1) gave one fraction (661 mg) as an branched and the linear product was determined to be 13 : 87.

1

oil of high viscosity. According to ¹H NMR spectroscopy, the 80b: R_f= 0.18 (PE–MTBE, 9 : 1). H NMR (500 MHz, CDCl₃) δ =

fraction contained a mixture of 78b (597 mg, 1.41 mmol, 71%) 7.65 (d, J = 8.3 Hz, 2H), 7.39 (d, J = 6.6 Hz, 1H), 7.30–7.26 (m

and tosylated N-methylbenzylamine (64 mg, 0.23 mmol). Prior 3H), 7.25–7.20 (m, 4H), 7.19–7.12 (m, 3H), 6.53 (d, J = 15.9 Hz,

to tosylation and chromatography, the ratio of the branched 1H), 6.01 (dt, J = 15.8, 6.8 Hz, 1H), 5.16 (t, J = 7.5 Hz, 1H), 2.67

and the linear product was determined to be 9 : 91. 78b: R_f= (s, 3H), 2.40 (s, 3H), 2.32 (s, 2H), 2.29–2.08 (m, 3H), 1.90–1.80

1

0.24 (PE–MTBE, 12 : 1). H NMR (500 MHz, CDCl₃) δ = 7.64 (d, (m, 1H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 143.0 (C), 138.0

J = 8.3 Hz, 2H), 7.33–7.25 (m, 6H), 7.24–7.19 (m, 3H), 6.99 (br. (C), 137.3 (C), 136.6 (C), 135.0 (C), 130.5 (CH), 130.1 (CH),

t, J = 8.7 Hz, 2H), 6.30 (d, J = 15.9 Hz, 1H), 6.08 (dt, J = 15.9, 6.8 129.4 (CH), 128.7 (CH), 128.4 (CH), 128.1 (CH), 127.8 (CH),

Hz, 1H), 5.15 (t, J = 7.6 Hz, 1H), 2.65 (s, 3H), 2.40 (s, 3H), 127.2 (CH), 127.0 (CH), 126.0 (CH), 125.4 (CH), 59.4 (CH), 30.3

2.23–2.14 (m, 2H), 2.12–2.04 (m, 1H), 1.90–1.83 (m, 1H) ppm. (CH₂), 30.2 (CH₂), 28.8 (CH₃), 21.5 (CH₃), 19.8 (CH₃) ppm. IR

1

¹³C NMR (125 MHz, CDCl₃) δ = 161.9 (d, J_C,F= 245.9 Hz, CF), (ATR) v_max= 3064 (w), 3031 (w), 2928 (w), 2868 (w), 1600 (w),

143.0 (C), 138.0 (C), 137.2 (C), 133.6 (d, ⁴J_C,F= 3.2 Hz, C), 129.4 1496 (w), 1456 (m), 1336 (s), 1157 (vs), 1090 (m), 936 (s), 815

3

(CH), 128.4 (CH), 128.0 (CH), 127.3 (d, J_C,F= 7.8 Hz, CH), (m), 736 (s), 701 (vs), 660 (vs) cm⁻¹. MS (ESI+) m/z = 442

2

127.1 (CH), 115.3 (d, J_C,F= 21.5 Hz, CH), 59.4 (CH), 30.3 ([M + Na]⁺). HRMS (ESI+) m/z calcd for C₂₆H₂₉NO₂SNa

(CH₂), 29.8 (CH₂), 28.7 (CH₃), 21.4 (CH₃) ppm. ¹⁹F NMR 442.1817 ([M + Na]⁺), found 442.1814.

(500 MHz, CDCl₃) δ = −115.5 ppm. IR (ATR) v_max= 3059 (w),

para-Toluenesulfonamide 81b. General procedure D was

3031 (w), 2948 (w), 2920 (w), 1598 (m), 1508 (m), 1452 (m), used to synthesize 81b from N-methylbenzylamine (38,

1336 (s), 1228 (m), 1154 (s), 1088 (m), 972 (m), 927 (s), 820 (m), 242 mg, 2.0 mmol) and (E)-1-(ortho-methoxyphenyl)-1,3-buta-

699 (s), 656 (s) cm⁻¹. MS (ESI+) m/z = 446 ([M + Na]⁺). HRMS diene (75, 481 mg, 3,0 mmol). Purification by flash column

(ESI+) m/z calcd for C₂₅H₂₆NO₂SFNa 446.1566 ([M + Na]⁺), chromatography (PE–MTBE, 1 : 1) gave one fraction as an oil of

found 446.1560.

high viscosity. According to ¹H NMR spectroscopy, the fraction

para-Toluenesulfonamide 79b. General procedure D was contained 81b (574 mg, 1.32 mmol, 66%) and trace amounts

used to synthesize 79b from N-methylbenzylamine (38, of the corresponding branched product. Prior to tosylation

242 mg, 2.0 mmol) and (E)-1-(para-methoxyphenyl)-1,3-buta- and chromatography, the ratio of the branched and the linear

diene (73, 481 mg, 3.0 mmol). Purification by flash column product was determined to be 11 : 89. 81b: R_f= 0.44 (PE–

1

chromatography (PE–MTBE, 6 : 1) gave one fraction as an oil of MTBE, 9 : 1) H NMR (500 MHz, CDCl₃) δ = 7.63 (d, J = 8.3 Hz,

high viscosity. According to ¹H NMR spectroscopy, the fraction 2H), 7.36 (dd, J = 7.6, 1.4 Hz, 1H), 7.28–7.15 (m, 8H), 6.89 (t,

contained 79b (524 mg, 1.20 mmol, 60%) and trace amounts J = 7.3 Hz, 1H), 6.84 (d, J = 8.2, 1H), 6.62 (d, J = 16.0 Hz, 1H),

of the corresponding branched product. Prior to tosylation 6.13 (dt, J = 15.9, 6.7 Hz, 1H), 5.13 (t, J = 7.4 Hz, 1H), 3.82 (s,

and chromatography, the ratio of the branched and the linear 3H), 2.63 (s, 3H), 2.37 (s, 3H), 2.20–2.03 (m, 3H), 1.85–1.76 (m,

product was determined to be 10 : 90. 79b: R_f= 0.30 (PE– 1H) ppm. ¹³C NMR (125 MHz, CDCl₃) δ = 156.3 (C), 142.9 (C),

MTBE, 6 : 1). ¹H NMR (500 MHz, CDCl₃) δ = 7.65 (d, J = 8.3 Hz, 138.2 (C), 137.3 (C), 129.9 (CH), 129.5 (CH), 128.4 (CH), 128.1

2H), 7.29–7.24 (m, 5H), 7.24–7.21 (m, 4H), 6.85 (d, J = 8.7 Hz, (CH), 127.7 (CH), 127.2 (CH), 126.5 (C), 126.5 (CH), 125.4 (CH),

2H), 6.27 (d, J = 15.9 Hz, 1H), 6.02 (dt, J = 15.8, 6.6 Hz, 1H), 120.6 (CH), 110.8 (CH), 59.6 (CH), 55.4 (CH₃), 30.4 (CH₂), 28.8

5.14 (t, J = 7.4 Hz, 1H), 3.81 (s, 3H), 2.65 (s, 3H), 2.40 (s, 3H), (CH₃), 21.5 (CH₃) ppm. IR (ATR) v_max= 3063 (w), 3031 (w),

2.22–2.04 (m, 3H), 1.87–1.79 (m, 1H) ppm. ¹³C NMR (125 MHz, 2924 (w), 2851 (w), 1597 (m), 1489 (m), 1455 (m), 1333 (s), 1242

CDCl₃) δ = 158.8 (C), 143.0 (C), 138.1 (C), 137.3 (C), 130.3 (C), (s), 1155 (vs), 1088 (m), 1027 (m), 933 (s), 813 (m), 751 (s), 700

130.1 (CH), 129.4 (CH), 128.4 (CH), 128.0 (CH), 127.7 (CH), (vs), 658 (vs) cm⁻¹. MS (ESI+) m/z = 458 ([M + Na]⁺). HRMS

127.2 (CH), 127.0 (CH), 126.9 (CH), 59.5 (CH), 55.3 (CH₃), 30.4 (ESI+) m/z calcd for C₂₆H₂₉NO₃SNa 458.1766 ([M + Na]⁺), found

(CH₂), 29.9 (CH₂), 28.8 (CH₃), 21.5 (CH₃) ppm. IR (ATR) v_max

=

458.1778.

Dalton Trans., 2015, 44, 12149–12168 | 12167

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Paper

Dalton Transactions

B. J. Baron, A. C. Behrle, J. A. R. Schmidt and L. L. Schafer,

Tetrahedron, 2013, 69, 5737; (m) J. Dörfler and S. Doye,

Eur. J. Org. Chem., 2014, 2790; (n) E. Chong, J. W. Brandt

and L. L. Schafer, J. Am. Chem. Soc., 2014, 136, 10898.

6 Zirconium catalysts: J. A. Bexrud, P. Eisenberger,

D. C. Leitch, P. R. Payne and L. L. Schafer, J. Am. Chem.

Soc., 2009, 131, 2116.

Acknowledgements

We thank the Deutsche Forschungsgemeinschaft for financial

support of our research as well as Jessica Reimer and Leoni

Fritsche for experimental assistance.

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Eur. J. Org. Chem., 2008, 2731; (b) R. Kubiak, I. Prochnow

and S. Doye, Angew. Chem., Int. Ed., 2009, 48, 1153;

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12168 | Dalton Trans., 2015, 44, 12149–12168

Article Doi

Intermolecular hydroaminoalkylation of alkenes and dienes using a titanium mono(formamidinate) catalyst

DOI: 10.1039/c4dt03916e

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Full text of DOI:10.1039/c4dt03916e

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