Rhodium-catalyzed asymmetric amination of allylic trichloroacetimidates

Article abstract of DOI:10.1055/s-0032-1316921

A summary is presented of dynamic kinetic asymmetric transformations of racemic allylic trichloroacetimidates in the presence of chiral diene-ligated rhodium catalysts. The reaction is applicable to a wide variety of secondary and tertiary trichloroacetimidates containing aniline or benzylamine nucleophiles, affording nitrogen-containing tertiary and quaternary centers in good yields and with high levels of regio- and enantioselectivity. This catalytic method addresses many of the limitations previously associated with syntheses of these compounds. Georg Thieme Verlag Stuttgart - New York.

Full text of DOI:10.1055/s-0032-1316921

SPECIAL TOPIC
▌2101
sRpehciaol tdopiiuc m-Catalyzed Asymmetric Amination of Allylic Trichloroacetimidates
Asymmetric Amination of Allylic Trichloroacetimidates
Jeffrey S. Arnold, Hien M. Nguyen*
Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA
E-mail: hien-nguyen@uiowa.edu
Received: 22.02.2013; Accepted after revision: 20.03.2013
olution-type methods, these racemic substrates have the
Abstract: A summary is presented of dynamic kinetic asymmetric
advantage of being easily prepared from allylic alcohols
transformations of racemic allylic trichloroacetimidates in the pres-
derived by vinylic addition reactions of a variety of alde-
hydes and ketones. Furthermore, they react more rapidly
ence of chiral diene-ligated rhodium catalysts. The reaction is appli-
cable to
a
wide variety of secondary and tertiary
trichloroacetimidates containing aniline or benzylamine nucleo- than their linear counterparts because of the lower degree
of steric congestion at the olefin moiety.7 At the start of
philes, affording nitrogen-containing tertiary and quaternary cen-
ters in good yields and with high levels of regio- and
enantioselectivity. This catalytic method addresses many of the lim-
DYKAT-type9 resolutions that gave enantiopure allylic
itations previously associated with syntheses of these compounds.
our investigation, there were few reports of kinetic8 or
amine products.
Key words: asymmetric catalysis, aminations, rhodium, catalysis,
Following our successes with transition metal-catalyzed
stereoselective transformations with glycal and glycosyl
trichloroacetimidates,10 we investigated amination reac-
tions with allylic substrates bearing a branched trichloro-
acetimidate leaving group.11 Taking our lead from the
pioneering work of Evans and co-workers in developing
rhodium-catalyzed enantiospecific amination reactions
with secondary allylic carbonates,12 we selected rhodium
catalysts in combination with allylic trichloroacetimidates
for our studies. In 2010, we reported a high-yielding re-
gioselective preparation of α-substituted allylic aryl
amines from secondary trichloroacetimidates and a wide
range of anilines.7a In 2011, we described a new method
for the preparation of α,α-disubstituted allylic aryl
amines.13 Our regioselective amination7a,13 ultimately pro-
vided a path to the discovery of rhodium-catalyzed
DYKAT with aniline nucleophiles.
imidates
Chiral amine functional groups are widely distributed in
the architecture of the natural world, and they have been
embedded into many materials, catalysts, pharmaceuti-
cals, and agrochemicals to impart a range of desirable
structural, physical, and chemical properties.1 As a result,
the development of new strategies for introducing nitro-
gen into organic molecules in a highly selective manner
continues to be a focus of investigation.2 One major area
that continues to evolve is the utilization of transition met-
als (such as palladium,3 iridium,4 or rhodium5) to catalyze
asymmetric aminations in allylic systems. These methods
produce allylic amine moieties that are valuable precur-
sors for subsequent transformations. In general, the reac-
tions employ linear allylic acetates or carbonates,
providing secondary branched amines in good yields and
with high regio- and enantioselectivities.
To clarify the stereochemical outcome of our allylic ami-
nation, we performed control experiments with enantio-
merically enriched allylic trichloroacetimidate 4 (98% ee)
(Scheme 2).7a The reaction was not enantiospecific, as ev-
idenced by the significant degree of racemization of the
amination product 5 (<7% ee). This result is in stark con-
Alternatively, enantiomerically enriched amines can be
prepared by transition-metal catalyzed dynamic kinetic
asymmetric transformations (DYKATs)6 of branched al-
lylic electrophiles (Scheme 1). Besides their utility in res-
R3
MLn
HN
R1
R1
matched (k1)
LnM
R1 LG
R2
R2
R2
R3NH2
ionization
1
2
3
π-σ-π
LG = acetate, carbonate, imidate
R3
1 MLn
R1 HN
mismatched (k2)
R
R1
LnM
LG
R2
R2
R2
R3NH2
ionization
ent-2
ent-3
ent-1
Scheme 1 Transition metal-catalyzed asymmetric aminations of branched allylic electrophiles
SYNTHESIS 2013, 45, 2101–2108
Advanced online publication: 30.04.2013
0
0
3
9
-
7
8
8
1
1
4
3
7
-
2
1
0
X
DOI: 10.1055/s-0032-1316921; Art ID: SS-2013-C0145-ST
© Georg Thieme Verlag Stuttgart · New York

2102
J. S. Arnold, H. M. Nguyen
SPECIAL TOPIC
trast to other transition-metal-catalyzed allylic substitu- obtained by using 2 mol% of dichlorotetrakis(ethyl-
tion reactions, which have been reported to provide ene)dirhodium and 4 mol% of the chiral diene ligand 8 in
products with net retention of stereochemistry.12 The out- methyl tert-butyl ether at 25 °C for one hour (Scheme 3).
come of this experiment can be rationalized by comparing This DYKAT process could be applied to a number of ter-
the rate of equilibration of diastereomeric organorhodium tiary allylic trichloroacetimidates 6 and aniline nucleo-
complexes (for example, 2 and ent-2) with that of nucleo- philes 7, providing the corresponding α,α-disubstituted
philic attack by aniline (Scheme 1). We hypothesized that allylic N-arylamines 9 in moderate-to-high yields (51–
the rate of aniline substitution (k1 and k2) is slower than 92%)
and
good-to-excellent
regioselectivities
that of π–σ–π interconversion, resulting in racemization in [branched/linear (b/l) = 5:1–99:1] and enantiomeric ex-
the amine product 3. On the basis of this study, we ex- cesses (52–96% ee). A current limitation of the amination
plored the possibility of rendering the process regio- and reaction with tertiary trichloroacetimidates is that only
enantioselective. By employing a chiral ligand, a more moderate regio- and enantioselectivities are achieved with
sterically encumbered environment is established, which substrates lacking a chelating functional group in the β-
slows down the rate of substitution by aniline nucleo- position.
philes and increases the time allowed for the equilibration
between the two diastereomeric complexes, 2 and ent-2.
An unfavorable interaction between one of the two π-al-
In an effort to expand the capabilities of the DYKAT
method, we pursued the development of a method for pre-
paring enantiopure α-substituted allylic N-methylaryl-
lylrhodium intermediates will determine which enantio-
amines (Scheme 4) through regio- and enantioselective
mer of the amination product (3 or ent-3) is formed
amination of secondary trichloroacetimidates. A number
of challenges had to be addressed in developing such a
preferentially.
DYKAT process. First, secondary allylic trichloroacet-
CF3
[RhCl(ethylene)2]2 (1 mol%)
(PhO)3P (4 mol%)
imidates are less sterically congested than their tertiary
counterparts, and so nucleophilic attack by anilines14
might be faster than the π–σ–π interconversion between
the diastereomeric π-allylrhodium complexes. Secondly,
low regioselectivity has been reported in iridium-cata-
lyzed asymmetric aminations with N-methylanilines.4e
Despite these potential difficulties, we chose to examine
the rhodium-catalyzed DYKAT of a variety of racemic
secondary trichloroacetimidates with N-methylanilines.16
Gratifyingly, the reaction was most effective when we
used the commercially available Hayashi chiral diene li-
gand 12 (Scheme 4). The highest yield, regio- and enantio-
selectivity were obtained with 5 mol% of dichloro-
tetrakis(ethylene)dirhodium and 10 mol% of the bicyc-
lo[2.2.2]octadiene ligand 12 in 1,4-dioxane for one hour.
The transformation can be applied to a number of N-meth-
ylanilines 10 with secondary allylic imidates 11 (Scheme
4). Allylic N-methyl arylamines 13 were obtained in good
yields (57–95%) and high enantioselectivities (83–96%
ee). High regioselectivity was also observed for all the
substrates. The reaction shows a high tolerance to various
functional groups, including allylic imidates lacking ac-
cessible oxygen atoms at the β-position.
CCl3
NH
THF, 40 °C, 1 h
O
HN
TBSO
TBSO
F3C
NH2
(S)-4
5
90%
98% ee
< 7% ee
Scheme 2 Rhodium(I)-catalyzed amination of enantiomerically en-
riched trichloroacetimidate 4
We commenced our studies on DYKAT reactions using
tertiary allylic trichloroacetimidates. We surmised that
these substrates might slow down the rate of nucleophilic
attack by aniline.14 To mimic the regioselective conditions
that worked best with dichlorobis(norbornadiene)dirhodi-
um as catalyst,13 we investigated a number of chiral diene
ligands.7c,15 We found that Hiyashi’s bicyclo[2.2.2]octadi-
enes were the most effective.15c,d We continued our opti-
mization studies by varying the electronic and steric
properties of the aryl ring of the chiral diene and observ-
ing the effects on the DYKAT reaction. We found an op-
timal balance occurred in the case of the electron-
withdrawing diene ligand 8 (Scheme 3), presumably as a
result of increased back-donation and, therefore, binding
affinity to the rhodium center.14 For all substrates, the op-
timal yields and regio- and enantioselectivities were
To expand the range of substrates available for the
DYKAT process, we examined the reactions of a variety
CCl3
R3
[RhCl(ethylene)2]2
(2–5 mol%)
R2
O
NH
R3
N
R2
+
Me
R1
R1
N
MTBE, 25 °C, 1 h
H
Me
6
4-FC6H4
7
9
yield = 51–92%
b/l = 5:1–99:1
ee = 52–96%
C6H4-4-F
8
(4–10 mol%)
Scheme 3 Rhodium-catalyzed DYKAT of racemic tertiary allylic trichloroacetimidates with anilines
Synthesis 2013, 45, 2101–2108
© Georg Thieme Verlag Stuttgart · New York

SPECIAL TOPIC
Asymmetric Amination of Allylic Trichloroacetimidates
2103
Scheme 4 Rhodium-catalyzed DYKAT of racemic secondary allylic trichloroacetimidates with N-methylanilines
of aniline and benzylamine nucleophiles 17a–f with the methylbenzylamine (17f) in the amination provided the
secondary trichloroacetimidates 14–16 (Table 1). Tri- allylic amines 33–35 in moderate yields, regioselectivi-
chloracetimidate 14 (Table 1, entry 1) possesses a β-oxy- ties, and enantiomeric excesses.
gen substituent that can provide additional chelation
control along the reaction coordinate, whereas the allylic
imidates 15 and 16 lack such an ether oxygen. Substrate
To illustrate the efficacy of our rhodium-catalyzed
DYKAT method, we transformed the allylic N-methyl-
anisidine 31 (Table 1, entry 5) into the corresponding N-
16, which contains the α-branching cyclohexyl group, has
methylhomophenylalanine derivatives 37–39,16 which are
been reported to produce low regioselectivity in amina-
found in antillatoxin B, a potent activator of sodium-ion
tion reactions.12d Although raising the temperature to
channels (Scheme 5).17 This showed that anilines function
40 °C improved the yield and enantioselectivity with the
not only as competent nucleophiles in our method, but can
also serve as masking groups, ultimately providing the en-
antiomerically enriched N-methylamine 36, a synthetical-
ly useful intermediate for bioactive targets.
secondary substrates 14–16, the regioselectivity tended to
be higher at room temperature. As shown in Table 1, the
electron-deficient primary aniline 17a (entry 1) and the
electron-rich primary aniline 17b (entry 2) gave the corre-
sponding allylic amination products 18–23 in good yields
(82–92%) and excellent regioselectivities (b/l = 20:1 to
>99:1) and enantioselectivities (80– 95% ee). Even the
ortho-methylated aniline 17c (entry 3) gave the corre-
sponding N-arylamines 24–26 in high regioselectivities
and enantiomeric excesses, highlighting the efficacy of
our rhodium-catalyzed method with sterically challenging
nucleophiles. Entries 4 and 5 clearly illustrate the elec-
tronic effects of the para-substituents on the aryl rings in
the N-methylanilines 17d and 17e. The benzyloxyimidate
14 reacted efficiently with the electron-deficient aniline
17d to give the allylic amine 27 in 72% yield with a good
Scheme 5 Preparation of N-methylhomophenylalanine derivatives.
regioselectivity (b/l = 30:1) and 93% ee (entry 4), whereas
Reagents and conditions: (a) CAN, MeCN–H2O, 15 min; (b) Boc2O,
K2CO3, THF–H2O (1:1); (c) RuCl3, NaIO4; (d) Ac2O, py; (e) O3,
NaOH, MeOH.
the reaction of imidate 15 with this nucleophile was low-
yielding (42%) and showed poor selectivity (b/l = 2:1;
57% ee). No amination product was observed with the α-
branching cyclohexyl substrate 16 (entry 4). A marked
difference in reactivity was observed in the reaction of the
electron-rich 4-methoxy-N-methylaniline (17e; entry 5)
with imidate 14. Although the product 30 was isolated in
high yield, the enantioselectivity was much lower (56%
ee) than that with electron-deficient aniline 17d (93% ee,
entry 4). This outcome can be rationalized in terms of
competition between the rate of nucleophilic substitution
and that of π–σ–π interconversion (Scheme 1). In contrast,
when imidate 15 was treated with aniline 17e, the amina-
tion product 31 was isolated in a higher yield (92%) and
with greater selectivity (b/l = 19:1; 85% ee; entry 5) than
when imidate 15 was paired with electron-withdrawing
aniline 17d (42%; 57% ee; b/l = 2:1) (entry 4). To our de-
light, we found that the DYKAT process could also be ap-
plied to alkyl amines (entry 6). For instance, the use of N-
In conclusion, we have developed a highly versatile rho-
dium-catalyzed DYKAT reaction of racemic secondary
and tertiary trichloroacetimidates with a wide variety of
anilines, N-methylanilines, and benzylamines. The reac-
tion is operationally simple and displays broad functional-
group tolerance, providing a number of nitrogen-contain-
ing tertiary and quaternary centers in high yields and high
regio- and enantioselectivities. The utility of this reaction
has been highlighted by a simple synthesis of N-methyl-
homophenylalanine derivatives. Additional studies of the
substrate scope, mechanistic details of the DYKAT reac-
tion, and applications of the DYKAT process to synthetic
targets of interest, are currently under investigation and
will be reported in due course.
© Georg Thieme Verlag Stuttgart · New York
Synthesis 2013, 45, 2101–2108

2104
J. S. Arnold, H. M. Nguyen
SPECIAL TOPIC
Table 1 Regio- and Enantioselective Allylic Aminations with a Wide Range of Anilines and Benzylic Amines
Entry
1
Amine
Product
Temp (°C)
Time (h)
Yielda (%)
b/lb
eec
F
18, R = CH2OBn
19, R = (CH2)2Ph
20, R = Cy
40
40
25
1
1
1
90
92
82
>99:1
>99:1
20:1
87
93
90
H2N
17a
OMe
21, R = CH2OBn
22, R = (CH2)2Ph
23, R = Cy
40
40
25
1
1
2
86
83
82
28:1
>99:1
>99:1
80
89
95
2
3
H2N
17b
Me
24, R = CH2OBn
25, R = (CH2)2Ph
26, R = Cy
40
40
25
1
1
22
75
81
44
>99:1
90:1
79:1
90
96
82
H2N
17c
CF3
27, R = CH2OBn
28, R = (CH2)2Ph
29, R = Cy
40
40
25
1
20
22
72
42
0
30:1
2:1
-
93d
57
-
Me
N
4
H
17d
OMe
30, R = CH2OBn
31, R = (CH2)2Ph
32, R = Cy
40
40
25
1
1
2
88
92
88
52:1
19:1
11:1
56
Me
N
5
6
85d
96d
H
17e
Me
N
Bn
33, R = CH2OBn
34, R = (CH2)2Ph
35, R = Cy
40
25
25
22
24
22
51
59
67
8:1
5:1
18:1
34
53
66
H
17f
a Isolated yield.
b Determined by GC.
c Determined by HPLC.
d Previously reported.
All reactions were performed under positive argon pressure in oven-
dried Schlenk flasks fitted with glass stoppers. Organic solutions
were concentrated by rotary evaporation below 40 °C at 25 Torr.
Analytical TLC and GC were routinely used to monitor the progress
of the reactions. TLC was performed using glass plates precoated
with 230- to 400-mesh silica gel impregnated with a fluorescent in-
dicator (250 nm). Visualization was accomplished using UV radia-
tion, KMnO4, or phosphomolybdic acid. Dry solvents were
obtained from an SG Waters solvent-purification system containing
activated alumina columns under argon pressure, or they were pur-
chased from Sigma-Aldrich in Sure/Seal bottles. The Rh catalysts
and chiral diene ligands were handled and transferred to Schlenk
flasks under N2 in a glove box. All chemicals and reagents were ob-
tained from commercial vendors and used without further purifica-
tion. Trichloroacetimidate substrates 14, 15, and 16 were prepared
by following the procedures described in the literature.
Monitoring by GC was performed on an Agilent 6850 with an au-
tosampler fitted with an HP-1 (30 m × 0.320 mm) column operated
at a temperature gradient of 100–250 °C over 10 min. Flash chro-
matography was performed on a Teledyne Isco CombiFlash Rf sys-
tem using normal-phase pre-column cartridges and gold high-
performance columns. Values of the ee were determined on Agilent
1200-series HPLC equipment with a Diacel Chiralcel (4.6 × 250
mm) OD-H or a Diacel Chiralcel OJ-3 (4.6 × 150 mm) column fitted
with a guard column. The flow rates and mobile phases were as in-
1
dicated below. All H NMR spectra were recorded on a Bruker
Avance DRX 400 MHz spectrometer. All 13C NMR spectra were re-
corded on the same instrument at 100 MHz. Chemical shifts ex-
pressed in ppm (δ scale) are referenced to residual CHCl3 (1H: δ =
7.24 ppm, 13C: δ = 77.23 ppm) in the NMR solvent. IR spectra were
recorded on a Jasco 4100 FT/IR spectrometer. Optical rotations
were measured on a Jasco P-2000 polarimeter at r.t. High-resolution
Synthesis 2013, 45, 2101–2108
© Georg Thieme Verlag Stuttgart · New York

SPECIAL TOPIC
Asymmetric Amination of Allylic Trichloroacetimidates
2105
time-of-flight mass spectrometry with electrospray ionization in
positive mode was performed on a Waters QTOF Premier instru-
ment.
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane, 2 μL injection, 4.6 × 150
mm Chiralcel OJ-3, 1 mL/min, 2.5% i-PrOH in hexanes, 254 nm;
major: 4.2 min, minor: 4.5 min: 90% ee.
IR (film): 3422, 2923, 2851, 1507, 1449, 1315, 1289, 993, 917, 816
cm–1.
1H NMR (CDCl3, 400 MHz): δ = 6.82 (t, J = 8.8 Hz, 2 H), 6.49 (dd,
J = 9.1, 4.4 Hz, 2 H), 5.75–5.62 (m, 1 H), 5.14 (d, J = 2.0 Hz, 1 H),
5.11 (dd, J = 3.8, 1.5 Hz, 1 H), 3.53 (br s, 2 H), 1.84–1.62 (m, 5 H),
1.48–1.44 (m, 1 H), 1.25–1.03 (m, 5 H).
13C NMR (CDCl3, 100 MHz): δ = 155.7, (d, JCF = 234 Hz), 144.5,
138.5, 116.1, 115.8, 115.5, 114.3, 114.2, 62.0, 42.9, 29.7, 29.5,
26.7, 26.5, 26.4.
Alkenylanilines 18–35; General Procedure
A 10 mL, oven-dried, Schlenk flask was charged with [RhCl(ethyl-
ene)2]2 (2.7 mg, 7.0 μmol, 5 mol%) and (1S,4S)-2,5-diphenylbicyc-
lo[2.2.2]octa-2,5-diene (12; 3.6 mg, 14 μmol, 10 mol%) in a glove
box. The flask was sealed and removed from the glove box, 1,4-di-
oxane (0.35 mL) was added, and the mixture was stirred for 15 min
to give a bright-red soln. A separate 10 mL Schlenk flask was
charged with appropriate allylic imidate 14–16 (1.0 equiv), 1,4-di-
oxane (0.35 mL), and aniline 17 (1.5 equiv). The Rh catalyst soln
was then transferred by means of a purged syringe to the flask con-
taining the soln of the imidate and 17. The flask was immediately
placed in an oil bath at r.t. or 40 °C and the mixture was stirred un-
der argon at 40 °C or r.t. while the progress of the reaction was mon-
itored (GC). The crude mixture was purified by direct adsorption
onto a dry 5 g Teledyne Isco silica gel cartridge under vacuum fol-
lowed by elution onto an equilibrated 24 g silica gel flash column
(0–20% EtOAc–hexane).
N-{1-[(Benzyloxy)methyl]prop-2-en-1-yl}-4-methoxyaniline
(21)
Prepared by the general procedure from allylic imidate 14 (45 mg,
0.14 mmol, 1.0 equiv) and aniline 17b (26 mg, 0.21 mmol, 1.5
equiv) at 40 °C for 1 h to give a brown oil; yield: 27 mg (86%; b/l
28:1); [α]D25 –11.2 (c 2.00, CHCl3).
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane, 2 μL injection, 4.6 × 250
mm Chiralcel OD-H, 1 mL/min, 5% i-PrOH in hexanes, 254 nm;
major: 9.3 min, minor: 9.8 min: 80% ee.
N-{1-[(Benzyloxy)methyl]prop-2-en-1-yl}-4-fluoroaniline (18)
Prepared by the general procedure from allylic imidate 14 (45 mg,
0.14 mmol, 1.0 equiv) and aniline 17a (20 μL, 0.21 mmol, 1.5
equiv) at 40 °C for 1 h to give a light-brown oil; yield: 34 mg (90%;
b/l >99:1); [α]D25 –7.0 (c 2.00, CHCl3).
IR (film): 3387, 2931, 2902, 2857, 2832, 1601, 1509, 1463, 1453,
1233, 1178, 1097, 1036, 992, 818, 736, 697 cm–1.
1H NMR (CDCl3, 400 MHz): δ = 7.36–7.27 (m, 5 H), 6.74 (d, J =
9.0 Hz, 2 H), 6.60 (d, J = 9.0 Hz, 2 H), 5.87–5.79 (m, 1 H), 5.31 (dt,
J = 17.3, 1.3 Hz, 1 H), 5.18 (dt, J = 10.3, 1.2 Hz, 1 H), 4.56 (d, J =
12.0 Hz, 1 H), 4.52 (d, J = 12.0 Hz, 1 H), 3.98–3.94 (m, 1 H), 3.72
(s, 3 H), 3.60 (dd, J = 9.5, 4.5 Hz, 1 H), 3.53 (dd, J = 9.5, 6.4 Hz, 1
H).
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane, 2 μL injection, 4.6 × 150
mm Chiralcel OJ-3, 1 mL/min, 2.5% i-PrOH in hexanes, 254 nm;
major: 16.2 min, minor: 14.4 min: 87% ee.
IR (film): 3398, 2898, 2858, 1602, 1508, 1453, 1360, 1313, 1215,
1095, 1076, 1027, 992, 922, 819, 736, 696 cm–1.
13C NMR (CDCl3, 100 MHz): δ = 152.7, 141.8, 138.2, 137.9, 128.6,
128.0, 127.9, 116.9, 115.7, 115.0, 73.4, 72.8, 57.2, 56.0.
1H NMR (CDCl3, 400 MHz): δ = 7.37–7.27 (m, 5 H), 6.84 (t, J = 6.7
Hz, 2 H), 6.57–6.52 (m, 2 H), 5.84–5.76 (m, 1 H), 5.30 (dt, J = 17.3,
1.3 Hz, 1 H), 5.19 (dt, J = 10.3, 1.2 Hz, 1 H), 4.55 (d, J = 12.1 Hz,
1 H), 4.54 (d, J = 12.1 Hz, 1 H), 4.07 (s, 1 H, NH), 3.97–3.93 (m, 1
H), 3.61 (dd, J = 9.6, 4.3 Hz, 1 H), 3.51 (dd, J = 9.6, 6.5 Hz, 1 H).
13C NMR (CDCl3, 100 MHz): δ = 156.1 (d, JCF = 234 Hz), 144.1,
138.0, 137.4, 128.7, 128.1, 128.0, 117.1, 115.8, 115.6, 115.0, 114.9,
73.4, 72.7.
(4-Methoxyphenyl)[1-(2-phenylethyl)prop-2-en-1-yl]amine (22)
Prepared by the general procedure from allylic imidate 15 (43 mg,
0.14 mmol, 1.0 equiv) and aniline 17b (26 mg, 0.21 mmol, 1.5
equiv) at 40 °C for 1 h to give a dark-brown oil; yield: 31 mg (83%;
b/l >99:1); [α]D25 +1.5 (c 2.00, CHCl3).
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane, 2 μL injection, 4.6 × 250
mm Chiralcel OD-H, 0.6 mL/min, 2.5% i-PrOH in hexanes, 254
nm; major: 28.0 min, minor: 27.2 min: 89% ee.
(4-Fluorophenyl)[1-(2-phenylethyl)prop-2-en-1-yl]amine (19)
Prepared by the general procedure from allylic imidate 15 (43 mg,
0.14 mmol, 1.0 equiv) and aniline 17a (20 μL, 0.21 mmol, 1.5
equiv) at 40 °C for 1 h to give a light-brown oil; yield: 33 mg (92%;
b/l >99:1); [α]D25 +0.33 (c 2.00, CHCl3).
IR (film): 3395, 3081, 3061, 3025, 2998, 2932, 2856, 2830, 1602,
1508, 1463, 1453, 1441, 1231, 1178, 1036, 992, 817, 816, 747, 699
cm–1.
1H NMR (CDCl3, 400 MHz): δ = 7.29–7.25 (m, 2 H), 7.20–7.16 (m,
3 H), 6.73 (d, J = 8.8 Hz, 2 H), 6.51 (d, J = 8.8 Hz, 2 H), 5.78–5.69
(m, 1 H), 5.20 (d, J = 17.2 Hz, 1 H), 5.13 (d, J = 10.3 Hz, 1 H), 3.75
(q, J = 6.7 Hz, 1 H), 3.73 (s, 3 H), 3.36 (br s, 1 H, NH), 2.73 (t, J =
7.7 Hz, 2 H), 1.91–1.85 (m, 2 H).
13C NMR (CDCl3, 100 MHz): δ = 152.2, 142.0, 141.7, 140.3, 128.7,
128.6, 126.1, 115.7, 115.0, 114.9, 56.5, 55.9, 37.5, 32.3.
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane, 2 μL injection, 4.6 × 250
mm Chiralcel OD-H, 1 mL/min, 2.5% i-PrOH in hexanes, 254 nm;
major: 16.1 min, minor: 11.2 min: 93% ee.
IR (film): 3412, 3083, 3061, 3026, 3003, 2977, 2922, 2857, 1507,
1454, 1313, 1218, 992, 920, 817, 778, 749, 699 cm–1.
1H NMR (CDCl3, 400 MHz): δ = 7.29–7.24 (m, 2 H), 7.21–7.16 (m,
3 H), 6.83 (t, J = 8.8 Hz, 2 H), 6.46 (dd, J = 9.0, 4.4 Hz, 2 H), 5.78–
5.69 (m, 1 H), 5.18 (dt, J = 17.2, 1.3 Hz, 1 H), 5.14 (dt, J = 10.3, 1.2
Hz, 1 H), 3.74 (q, J = 6.1 Hz, 1 H), 3.50 (s, 1 H, NH), 2.73 (t, J =
6.9 Hz, 2 H), 1.92–1.87 (m, 2 H).
13C NMR (CDCl3, 100 MHz): δ = 155.9 (d, JCF = 233 Hz), 143.9,
141.8, 139.9, 128.7, 126.2, 115.8, 115.6, 114.5, 114.4, 56.2, 37.4,
32.4.
N-(1-Cyclohexylprop-2-en-1-yl)-4-methoxyaniline (23)
Prepared by the general procedure from allylic imidate 16 (40 mg,
0.14 mmol, 1.0 equiv) and aniline 17b (26 mg, 0.21 mmol, 1.5
equiv) at r.t. for 2 h to give a light-brown oil; yield: 28 mg (82%; b/l
>99:1); [α]D25 –10.7 (c 2.00, CHCl3).
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane, 2 μL injection, 4.6 × 150
mm Chiralcel OJ-3, 1 mL/min, 2.5% i-PrOH in hexanes, 254 nm;
major: 9.3 min, minor: 8.7 min: 95% ee.
N-(1-Cyclohexylprop-2-en-1-yl)-4-fluoroaniline (20)
Prepared by the general procedure from allylic imidate 16 (40 mg,
0.14 mmol, 1.0 equiv) and aniline 17a (20 μL, 0.21 mmol, 1.5
equiv) at r.t. for 1 h to give a dark-brown oil; yield: 27 mg (82%; b/l
20:1); [α]D25 –3.3 (c 2.00, CHCl3).
IR (film): 3405, 2922, 2850, 2831, 1509, 1481, 1463, 1448, 1232,
1178, 1038, 994, 915, 815 cm–1.
1H NMR (CDCl3, 400 MHz): δ = 6.73 (d, J = 8.8 Hz, 2 H), 6.53 (d,
J = 8.8 Hz, 2 H), 5.72–5.63, (m, 1 H), 5.13 (dt, J = 9.4, 1.2 Hz, 1 H),
© Georg Thieme Verlag Stuttgart · New York
Synthesis 2013, 45, 2101–2108

2106
J. S. Arnold, H. M. Nguyen
SPECIAL TOPIC
5.11 (dt, J = 18.3, 0.96 Hz, 1 H), 3.71 (s, 3 H), 3.53 (t, J = 6.5 Hz, 1
H), 3.41 (s, 1 H, NH), 1.85–1.64 (m, 5 H), 1.51–1.44 (m, 1 H), 1.28–
1.00 (m, 5 H).
13C NMR (CDCl3, 100 MHz): δ = 151.9, 142.4, 138.9, 115.9, 115.0,
equiv) at 40 °C for 1 h to give a brown oil; yield: 34 mg (72%; b/l
30:1). Spectral and analytical data were previously reported.16
N-Methyl-N-[1-(2-phenylethyl)prop-2-en-1-yl]-4-(trifluoro-
methyl)aniline (28)
Prepared by the general procedure from allylic imidate 15 (43 mg,
0.14 mmol, 1.0 equiv) and aniline 17d (30 μL, 0.21 mmol, 1.5
equiv) at 40 °C for 20 h to give a light-brown oil; yield: 19 mg
(42%; b/l 2:1); [α]D25 +9.0 (c 2.00, CHCl3).
114.8, 62.3, 56.0, 42.9, 29.7, 29.5, 26.8, 26.6, 26.5.
N-{1-[(Benzyloxy)methyl]prop-2-en-1-yl}-2-methylaniline (24)
Prepared by the general procedure from allylic imidate 14 (45 mg,
0.14 mmol, 1.0 equiv) and aniline 17c (23 μL, 0.21 mmol, 1.5
equiv) at 40 °C for 1 h to give a light-brown oil; yield: 28 mg (75%;
b/l >99:1); [α]D25 –11.3 (c 2.00, CHCl3).
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane, 2 μL injection, 4.6 × 250
mm Chiralcel OD-H, 0.6 mL/min, 1% i-PrOH in hexanes, 254 nm;
major: 10.2 min, minor: 10.7 min: 57% ee.
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane, 2 μL injection, 4.6 × 150
mm Chiralcel OJ-3, 0.6 mL/min, 1% i-PrOH in hexanes, 254 nm;
major: 22.5 min, minor: 24.4 min: 90% ee.
IR (film): 3085, 3063, 3027, 2943, 2858, 1616, 1529, 1496, 1478,
1454, 1385, 1329, 1200, 1164, 1111, 1071, 989, 925, 818, 748, 700
cm–1.
1H NMR (CDCl3, 400 MHz): δ (branched) = 7.41 (d, J = 8.8 Hz, 2
H), 7.25–7.22 (m, 2 H), 7.19–7.15 (m, 1 H), 7.11–7.07 (m, 2 H),
6.68 (d, J = 8.9 Hz, 2 H), 5.82–5.74 (m, 1 H), 5.16 (dt, J = 10.6, 1.5
Hz, 1 H), 5.09 (dt, J = 17.3, 1.4 Hz, 1 H), 4.33–4.28 (m, 1 H), 2.82
(s, 3 H), 2.58–2.51 (m, 1 H), 2.33 (q, J = 7.7 Hz, 1 H), 2.04–1.97
(m, 2 H).
13C NMR (CDCl3, 100 MHz): δ = 152.7, 141.4, 136.6, 128.7, 128.6,
126.6, 126.5, 126.3, 116.3, 111.9, 111.4, 59.0, 33.9, 32.9, 31.7.
HRMS (ESI): m/z [M + H]+calcd for C19H21NF3: 320.1626; found:
320.1609.
IR (film): 3405, 2895, 2857, 1605, 1586, 1508, 1477, 1448, 1359,
1313, 1262, 1102, 1050, 1026, 989, 920, 744, 715, 697 cm–1.
1H NMR (CDCl3, 400 MHz): δ = 7.34–7.30 (m, 5 H), 7.05–7.03 (m,
2 H), 6.66–6.59 (m, 2 H), 5.89–5.81 (m, 1 H), 5.32 (d, J = 17.3 Hz,
1 H), 5.21 (d, J = 10.4 Hz, 1 H), 4.56 (d, J = 12.0 Hz, 1 H), 4.55 (d,
J = 12.0 Hz, 1 H), 4.11–4.08 (m, 1 H, NH), 3.66–3.57 (m, 2 H), 2.15
(s, 3 H).
13C NMR (CDCl3, 100 MHz): δ = 145.7, 138.2, 137.7, 130.2, 128.7,
128.0, 127.8, 127.1, 122.6, 117.4, 116.8, 111.3, 73.2, 72.7, 55.9,
17.7.
[1-(2-Phenylethyl)prop-2-en-1-yl](2-tolyl)amine (25)
Prepared by the general procedure from allylic imidate 15 (43 mg,
0.14 mmol, 1.0 equiv) and aniline 17c (23 μL, 0.21 mmol, 1.5
equiv) at 40 °C for 1 h to give a light-brown oil; yield: 29 mg (81%;
b/l 90:1); [α]D25 –8.1 (c 2.00, CHCl3).
N-(1-(Benzyloxy)but-3-en-2-yl)-4-methoxy-N-methylaniline
(30)
Prepared by the general procedure from allylic imidate 14 (45 mg,
0.14 mmol, 1.0 equiv) and aniline 17e (29 mg, 0.21 mmol, 1.5
equiv) at 40 °C for 1 h to give a brown oil; yield: 37 mg (88%; b/l
52:1); [α]D25 +2.4 (c 2.00, CHCl3).
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane, 2 μL injection, 4.6 × 250
mm Chiralcel OD-H, 1 mL/min, 2.5% i-PrOH in hexanes, 254 nm;
major: 7.9 min, minor: 6.4 min: 96% ee.
HPLC: 2.5 mg/mL in 50:50 i-PrOH–hexane, 2 μL injection, 4.6 ×
250 mm Chiralcel OD-H, 0.6 mL/min, 1% i-PrOH in hexanes, 254
nm; major: 19.9 min, minor: 18.7 min: 56% ee.
IR (film): 3434, 3025, 2920, 2854, 1605, 1586, 1509, 1497, 1478,
1447, 1314, 1257, 990, 916, 744, 698, 682 cm–1.
IR (film): 3083, 3062, 3030, 2989, 2896, 2861, 2833, 1716, 1640,
1510, 1464, 1454, 1244, 1181, 1105, 1038, 993, 925, 816, 737, 699
cm–1.
1H NMR (CDCl3, 400 MHz): δ = 7.33–7.25 (m, 5 H), 6.81 (d, J =
9.0 Hz, 2 H), 6.79 (d, J = 9.2 Hz, 2 H), 5.88–5.80 (m, 1 H), 5.20 (dt,
J = 9.8, 1.4 Hz, 1 H), 5.19 (dt, J = 18.7, 1.6 Hz, 1 H), 4.50 (s, 2 H),
4.39–4.35 (m, 1 H), 3.75 (s, 3 H), 3.67 (dd, J = 9.8, 6.9 Hz, 1 H),
3.61 (dd, J = 9.8, 6.4 Hz, 1 H), 2.74, (s, 3 H).
1H NMR (CDCl3, 400 MHz): δ = 7.30–7.26 (m, 2 H), 7.21–7.17 (m,
3 H), 7.08–7.03 (m, 2 H), 6.62 (t, J = 7.4 Hz, 1 H), 6.51 (d, J = 7.9
Hz, 1 H), 5.83–5.75 (m, 1 H), 5.21 (dt, J = 17.2, 1.4 Hz, 1 H), 5.13
(dt, J = 10.3, 1.2 Hz, 1 H), 3.90 (q, J = 6.5 Hz, 1 H), 3.47 (s, 1 H,
NH), 2.73 (t, J = 7.5 Hz, 2 H), 2.1 (s, 3 H), 1.98–1.94 (m, 2 H).
13C NMR (CDCl3, 100 MHz): δ = 145.4, 141.9, 140.0, 130.3, 128.7,
127.1, 126.1, 121.8, 116.9, 115.5, 110.9, 55.4, 37.6, 32.5, 17.7.
N-(1-Cyclohexylprop-2-en-1-yl)-2-methylaniline (26)
Prepared by the general procedure from allylic imidate 16 (40 mg,
0.14 mmol, 1.0 equiv) and aniline 17c (23 μL, 0.21 mmol, 1.5
equiv) at r.t. for 22 h to give a light-brown oil; yield: 14 mg (44%;
b/l 79:1); [α]D25 +1.2 (c 2.00, CHCl3).
13C NMR (CDCl3, 100 MHz): δ = 152.3, 145.1, 138.4, 135.2, 128.5,
127.9, 127.8, 117.2, 116.2, 114.7, 73.3, 70.4, 62.0, 56.0, 33.6.
HRMS (ESI): m/z [M + H]+ calcd for C19H24NO2: 298.1807; found:
298.1791.
(4-Methoxyphenyl)methyl[1-(2-phenylethyl)prop-2-en-1-
yl]amine (31)
Prepared by the general procedure from allylic imidate 15 (43 mg,
0.14 mmol, 1.0 equiv) and aniline 17e (29 mg, 0.21 mmol, 1.5
equiv) at 40 °C for 1 h to give a light brown oil; yield: 36 mg (92%;
b/l 19:1). Spectral and analytical data were previously reported.16
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane 1 μL injection, 4.6 × 250
mm Chiralcel OD-H, 0.6 mL/min, 1% i-PrOH in hexanes, 254 nm;
major: 8.1 min, minor: 7.8 min: 82% ee.
IR (film): 3442, 2922, 1605, 1586, 1509, 1477, 1447, 1315, 1302,
1288, 1254, 1051, 984, 916, 794, 743, 713 cm–1.
1H NMR (CDCl3, 400 MHz): δ = 7.08–7.01 (m, 2 H), 6.61–6.54 (m,
2 H), 5.77–5.68 (m, 1 H), 5.16 (dt, J = 9.2, 1.4 Hz, 1 H), 5.14 (dt,
J = 18.4, 1.2 Hz, 1 H), 3.70–3.69 (m, 1 H), 3.56 (br s, 1 H, NH) 2.15
(s, 3 H), 1.88–1.74 (m, 5 H), 1.69–1.55 (m, 1 H), 1.27–1.05 (m, 5
H).
N-(1-Cyclohexylprop-2-en-1-yl)-4-methoxy-N-methylaniline
(32)
Prepared by the general procedure from allylic imidate 16 (40 mg,
0.14 mmol, 1 equiv) and aniline 17e (29 mg, 0.21 mmol, 1.5 equiv)
at 40 °C for 1 h to give a dark brown oil; yield: 32 mg (88%; b/l
11:1). Spectral and analytical data were previously reported.16
13C NMR (CDCl3, 100 MHz): Matches literature values.7a
N-{1-[(Benzyloxy)methyl]prop-2-en-1-yl}-N-methyl-4-(trifluo-
romethyl)aniline (27)
Prepared by the general procedure from allylic imidate 14 (45 mg,
0.14 mmol, 1.0 equiv) and aniline 17d (30 μL, 0.21 mmol, 1.5
N-Benzyl-1-(benzyloxy)-N-methylbut-3-en-2-amine (33)
Prepared by the general procedure from allylic imidate 14 (45 mg,
0.14 mmol, 1.0 equiv) and N-methylbenzylamine (17f; 27 μL, 0.21
mmol, 1.5 equiv) at 40 °C for 22 h to give a light-yellow oil; yield:
20 mg (51%; b/l 8:1); [α]D25 –4.4 (c 2.00, CHCl3).
Synthesis 2013, 45, 2101–2108
© Georg Thieme Verlag Stuttgart · New York

SPECIAL TOPIC
Asymmetric Amination of Allylic Trichloroacetimidates
2107
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane 1 μL injection, 4.6 × 250
mm Chiralcel OD-H, 0.15 mL/min, 1% i-PrOH in hexanes, 254 nm;
major: 41.9 min, minor: 40.5 min: 34% ee.
Acknowledgment
The authors are grateful for financial support from the University of
Iowa. J.S.A. thanks the Graduate College for a Summer Research
Fellowship.
IR (film): 3085, 3063, 3028, 2975, 2944, 2850, 2791, 1954, 1870,
1811, 1663, 1639, 1605, 1586, 1510, 1494, 1453, 1419, 1363, 1314,
1259, 1207, 1103, 1076, 1038, 1027, 994, 923 cm–1.
1H NMR (CDCl3, 400 MHz): δ = 7.32–7.21 (m, 10 H), 5.90–5.80
(m, 1 H), 5.26 (d, J = 10.4 Hz, 1 H), 5.20 (d, J = 17.3 Hz, 1 H), 4.53
(s, 2 H), 3.71–3.65 (m, 2 H), 3.57–3.48 (m, 2 H), 3.34–3.29 (q, J =
7.3 Hz, 1 H), 2.21 (s, 3 H).
Supporting Information for this article is available online at
http://www.thieme-connect.com/ejournals/toc/synthesis.SnoIufproi
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References
13C NMR (CDCl3, 100 MHz): δ = 135.3, 129.0, 128.5, 128.4, 127.9,
127.7, 127.0, 118.5, 73.3, 71.4, 65.2, 58.7, 38.5.
HRMS (ESI): m/z [M + H]+ calcd for C19H24NO: 282.1858; found:
282.1846.
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Applications; Nugent, T., Ed.; Wiley-VCH: Weinheim,
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(2) (a) Nugent, T. C.; El-Shazly, M. Adv. Synth. Catal. 2010,
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Saigo, K. J. Org. Chem. 1997, 62, 5508.
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Tverskoy, O.; Helmchen, G. Org. Lett. 2011, 13, 2810.
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Liu, W.; Dai, L.; Helmchen, G.; You, S. J. Am. Chem. Soc.
2011, 133, 19006.
N-Benzyl-N-methyl-5-phenylpent-1-en-3-amine (34)
Prepared by the general procedure from allylic imidate 15 (43 mg,
0.14 mmol, 1.0 equiv) and N-methylbenzylamine (17f; 27 μL, 0.21
mmol, 1.5 equiv) at r.t. for 24 h to give a clear oil; yield: 22 mg
(59%; b/l 5:1); [α]D25 –3.2 (c 2.00, CHCl3).
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane 1 μL injection, 4.6 × 150
mm Chiralcel OJ-3, 0.6 mL/min, 1% i-PrOH in hexanes, 254 nm;
major: 8.6 min, minor: 7.5 min: 53% ee.
IR (film): 3083, 3062, 3026, 2939, 2851, 2790, 1945, 1869, 1803,
1718, 1636, 1603, 1495, 1454, 1418, 1367, 1316, 1259, 1214, 1155,
1125, 1076, 1028, 998, 921, 740, 698 cm–1.
1H NMR (CDCl3, 400 MHz): δ = 7.33–7.13 (m, 10 H), 5.86–5.77
(m, 1 H), 5.24 (dd, J = 10.3, 1.8 Hz, 1 H), 5.08 (dd, J = 17.2, 1.3 Hz,
1 H), 3.64 (d, J = 13.3 Hz, 1 H), 3.39 (d, J = 13.2 Hz, 1 H), 2.99 (q,
J = 7.6 Hz, 1 H), 2.69–2.64 (m, 1 H), 2.15 (s, 3 H), 2.03–1.94 (m, 1
H), 1.81–1.72 (m, 1 H).
13C NMR (CDCl3, 100 MHz): δ = 142.8, 140.2, 136.7, 129.0, 128.7,
128.5, 128.4, 126.9, 125.9, 117.9, 65.8, 58.2, 37.6, 34.4, 32.9.
HRMS (ESI): m/z [M + H]+ calcd for C19H24N : 266.1909; found:
266.1885.
N-Benzyl-1-cyclohexyl-N-methylprop-2-en-1-amine (35)
Prepared by the general procedure from allylic imidate 16 (40 mg,
0.14 mmol, 1.0 equiv) and N-methylbenzylamine (17f; 27 μL, 0.21
mmol, 1.5 equiv) at r.t. for 22 h to give a clear semi-solid; yield: 23
mg (67%; b/l 18:1); [α]D25 –35.8 (c 2.00, CHCl3).
HPLC: 2 mg/mL in 50:50 i-PrOH–hexane 1 μL injection, 4.6 × 150
mm Chiralcel OJ-3, 0.6 mL/min, 1% i-PrOH in hexanes, 254 nm;
major: 8.6 min, minor: 7.5 min: 53% ee.
(5) (a) Cooke, M. L.; Xu, K.; Breit, B. Angew. Chem. Int. Ed.
2012, 51, 10876. (b) Lebel, H.; Spitz, C.; Leogane, O.;
Trudel, C.; Parmentier, M. Org. Lett. 2011, 13, 5460.
(c) Cochet, T.; Bellosta, V.; Roche, D.; Ortholand, J.-Y.;
Greiner, A.; Cossy, J. Chem. Commun (Cambridge) 2012,
48, 10745.
(6) (a) Trost, B. M.; Bunt, R. C.; Lemoine, R. C.; Calkins, T. L.
J. Am. Chem. Soc. 2000, 122, 5968. (b) Trost, B. M.; Toste,
F. D. J. Am. Chem. Soc. 2003, 125, 3090. (c) Trost, B.;
Fandrick, D.; Brodmann, T.; Stiles, D. Angew. Chem. Int.
Ed. 2007, 46, 6123. (d) Trost, B. M.; Fandrick, D. R.
Aldrichimica Acta 2007, 40, 59. (e) Trost, B. M.; Osipov,
M.; Dong, G. J. Am. Chem. Soc. 2010, 132, 15800.
(7) (a) Arnold, J. S.; Stone, R. F.; Nguyen, H. M. Org. Lett.
2010, 12, 4580. (b) Bartels, B.; García-Yebra, C.; Rominger,
F.; Helmchen, G. Eur. J. Inorg. Chem. 2002, 2569.
(c) Fischer, C.; Defieber, C.; Suzuki, T.; Carreira, E. M.
J. Am. Chem. Soc. 2004, 126, 1628.
IR (film): 3083, 3064, 3027, 2973, 2922, 2849, 2791, 1723, 1494,
1450, 1417, 1366, 1261, 1230, 1125, 1021, 977, 919, 833, 740, 699
cm–1.
1H NMR (CDCl3, 400 MHz): δ = 7.32–7.18 (m, 5 H), 5.64 (dt, J =
17.1, 9.9 Hz, 1 H), 5.23 (dd, J = 9.8, 2.0 Hz, 1 H), 4.96 (dd, J = 17.2,
2.0 Hz, 1 H), 3.60 (d, J = 13.5 Hz, 1 H), 3.33 (d, J = 13.5 Hz, 1 H),
2.51 (t, J = 9.6 Hz, 1 H), 2.16 (d, J = 13.2 Hz, 1 H), 2.09 (s, 3 H),
1.75–1.64 (m, 4 H), 1.52–1.44 (m, 1 H), 1.23–1.12 (m, 3 H), 0.94–
0.87 (m, 1 H), 0.85–0.74 (m, 1 H).
13C NMR (CDCl3, 100 MHz): δ = 140.7, 135.5, 128.9, 128.3, 126.7,
118.4, 72.1, 58.4, 38.8, 37.5, 30.9, 30.7, 27.1, 26.6.
HRMS (ESI): m/z [M + H]+ calcd for C17H26N: 244.2065; found:
244.2048.
N-Methyl-5-phenylpent-1-en-3-amine (36)
Preparation and analytical and spectral data as previously report-
ed.16
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