Lewis acid promoted Mannich type reactions of α,α-dichloro aldimines with potassium organotrifluoroborates

Article abstract of DOI:10.1016/j.tet.2007.06.003

Potassium phenylethynyltrifluoroborate and potassium styryltrifluoroborates react with α,α-dichlorinated aldimines in the presence of BF₃·OEt₂ as a Lewis acid to give a new stable class of functionalized propargylamines and allylamin

Full text of DOI:10.1016/j.tet.2007.06.003

Tetrahedron 63 (2007) 8921–8931
Lewis acid promoted Mannich type reactions of a,a-dichloro
aldimines with potassium organotrifluoroborates
*
Sara Stas and Kourosch Abbaspour Tehrani
Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
Received 22 December 2006; revised 30 May 2007; accepted 6 June 2007
Available online 9 June 2007
Abstract—Potassium phenylethynyltrifluoroborate and potassium styryltrifluoroborates react with a,a-dichlorinated aldimines in the
presence of BF3$OEt2 as a Lewis acid to give a new stable class of functionalized propargylamines and allylamines. The use of hexafluoro-
isopropanol as a co-solvent in this modified Petasis reaction allows high yield isolation of the target compounds.
Ó 2007 Elsevier Ltd. All rights reserved.
1. Introduction
a,a-dichloroaldehydes 1, which were evaluated as substrates
in a reaction with potassium organotrifluoroborates 4
(Scheme 1).
The boronic acid Mannich reaction (BAM reaction), also
known as the Petasis reaction, is a one-step multicomponent
process,involvinganorganoboronicacid, anamine, andacar-
bonyl derivative, which can produce novel multifunctional
molecules, includinggeometricallypure allylamines,1 a-ami-
no acids,2,3 anti-b-amino alcohols,4,5 a-arylglycines,6 amino
phenol derivatives,7 indolyl-N-substituted glycines,8 2-
hydroxymorpholines,9 a-hydrazinocarboxylic acids,10 a-(4-
N,N-dialkylamino-2-alkyloxyphenyl)carboxylic acids,11,12
and heterocyclic systems.13
In the classical Petasis reaction, secondary amines are pre-
dominantly used, giving rise to tertiary amine Mannich
products, which often require an extra deprotection step.
By applying the corresponding imines, this detour could
be avoided. To the best of our knowledge, the combined
use of potassium organotrifluoroborates and aldimines in
the presence of a Lewis acid in the Petasis reaction has not
been reported. Reactions of organometallic reagents with
imines are well known,18 and to a lesser extent with organo-
boron reagents.19–22 The addition of organocuprate$BF3
complexes or in situ prepared alkynyldifluoroboranes or
alkynylborates to aldimines afforded secondary amines in
good yields.19–21 Propargylamines are very much in demand
in medicinal chemistry, due to their pronounced physiolog-
ical acivities.23 The preparation of propargylic amines by
direct additions of alkynes to imines has been recently
reviewed by Bolm and Zani.24 Next to the advantage of using
imines as electrophiles, potassium organotrifluoroborates
offer several advantages over their corresponding boronic
acids and strongly basic organometallic reagents. Organo-
boronic acids are often subjected to dimerization and cyclic
trimerization to generate, respectively, boronic acid anhy-
drides and boroxines. Trifluoroborates are monomeric,
non-hygroscopic, crystalline solids that are indefinitely
stable in the air at room temperature.25 On the other hand,
2,2-dichloroaldehydes are valuable and very promising
bifunctional substrates in synthetic organic chemistry.26
The application of the corresponding a,a-dichloroimines
in the preparation of b,b-dichloroamines 5, more specific
of allylic and propargylic amines would allow us to inves-
tigate the reactivity of these highly functionalized
Only few papers report the use of potassium trifluoroborates
in Petasis reactions. Kabalka et al. reported the three-compo-
nent condensation of potassium alkynyltrifluoroborates with
secondary amines and salicylaldehydes, in the presence of
benzoic acid.14 Heterocyclic aldehydes such as pyridine-2-
carboxaldehyde also participate in a trifluoroborate Mannich
process with chlorotrimethylsilane as Lewis acid, and gave
rise to functionalized allylamines in 28–54% yield.13 This
variation of the boronic acid Mannich reaction also has
been extended to other carbonyl components like formalde-
hyde and ethyl glyoxylate.15 The reaction of potassium tri-
fluoroborates with in situ generated iminium species with
Lewis acid activation has been reported recently.16
In a previous attempt to extend the Petasis reaction to a,a-di-
chloroaldehydes 1, no b,b-dichloroamines 5 were observed,
instead, 1-aminoalkan-2-ones 3 were formed.17 Therefore
we turned our attention to the corresponding imines of the
Keywords: Boron; Imines; Addition reactions; Mannich bases.
* Corresponding author. Tel.: +32 (0) 26293292; fax: +32 (0) 26293304;
e-mail: kourosch.abbaspour.tehrani@vub.ac.be
0040–4020/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2007.06.003

8922
S. Stas, K. A. Tehrani / Tetrahedron 63 (2007) 8921–8931
Scheme 1. Synthesis of b,b-dichloroamines.
compounds. Therefore, we examined the borono Mannich
reaction between a,a-dichloroimines and potassium trifluoro-
borates in the presence of Lewis acids. Thus a new class
of acyclic b,b-dichloroamines 5 would become available,
which, to the best of our knowledge, has been prepared
only once before.27
for this conversion are SiCl4,30 gaseous BF3,31 Me3SiCl,32
and BF3$OEt2.16,33,34
In a preliminary attempt, N-(2,2-dichloro-1-propylidene)-
benzylamine (2aa) was reacted with potassium styryltri-
fluoroborate (4a) and BF3$OEt2. The presence of N-(4,4-
dichloro-1-phenylpent-1-en-3-yl)benzylamine (5aa) in the
crude reaction mixture was shown by 1H NMR. With regard
to the possible mechanism of this reaction some general
considerations may be made. The RBF2 species generated in
situ acts as a Lewis acid and hence activates the imine for
a nucleophilic attack.5,13 After all, the majority of electro-
philes in the Petasis reaction bear a hydroxyl group, suggest-
ing that the formation of a boronate adduct with a pendant
heteroatom on the electrophile is important for the reaction
to proceed.35
2. Results and discussion
The different a,a-dichloroimines 2 discussed in this article
were prepared by reacting a,a-dichloroaldehydes 128 with
primary amines in CH2Cl2 in the presence of anhydrous
MgSO4 as desiccant. The more sterically hindered a,a-di-
chloroaldehyde 1ce was transformed into the corresponding
imine using titanium(IV) chloride (Scheme 2, Table 1).
Both BF3$OEt2 and TMSCl were evaluated as Lewis acids in
this conversion, using 1 equiv of each of the three compo-
nents (imine, borate, and Lewis acid). A higher yield of
5aa was obtained with BF3$OEt2 as Lewis acid (24%,
GC–MS) than with Me3SiCl (8%, GC–MS).
Scheme 2. Synthesis of imines: Reagents and conditions: (i) Method a:
R2NH2 (0.95–1.5 equiv), CH2Cl2, reflux or 0 ꢀC or ꢁ10 ꢀC, 2 h; Method
b: R2NH2 (4 equiv), TiCl4 (0.6 equiv), Et2O, 0 ꢀC/rt, 2 h.
Different amounts of the styryltrifluoroborate and BF3$OEt2
were used in the BAM reaction on 2aa in order to determine
the optimal proportion of each compound. However, no clear
conclusion could be drawn from these experiments and all
attempts to purify the benzylamine 5aa failed. Because of
the problems encountered with the purification of 5aa, we
investigated another imine, namely N-(2,2-dichloro-1-pro-
pylidene)-tert-butylamine (2ab) as a substrate in this BAM
reaction. As a consequence of extensive optimization reac-
tions the optimal reaction condition for the boronic acid
Mannich reaction between an a,a-dichloroimine, potassium
trifluoroborate, and BF3$OEt2, was an equimolar overnight
reaction in dichloromethane at room temperature (Table 2,
entry 3). These conditions were used to carry out the BAM
reactions with the other a,a-dichloroimines 2 (Table 2).
The yield of the reactions with potassium styryltrifluoro-
borate (4a) increases with a less sterically hindering nitrogen
atom substituent of the imine. Electron donating substituents
in the styryl group led to better yields of the Mannich prod-
uct (entry 11) while electron withdrawing groups decreased
this yield (entry 12). Potassium phenyltrifluoroborate and 1-
phenylvinyltrifluoroborate were not reactive in the boronic
acid Mannich reaction with a,a-dichloroimines 2. Even
the electron-rich 4-methoxyphenyltrifluoroborate and 2,5-
dimethoxyphenyltrifluoroborate did not lead to any Mannich
product. Instead, the deborylated products, anisole and 1,4-
dimethoxybenzene were isolated in 34%. In case HFIP (vide
infra) was added as a co-solvent, 1,4-dimethoxybenzene was
isolated in 69% yield and anisole in 38% yield. When potas-
sium phenylethynyltrifluoroborate (4g) was used, the yields
First, as a control reaction, N-(2,2-dichloro-1-propylidene)-
benzylamine (2aa) was reacted with 1 equiv of styrylboronic
acid and BF3$Et2O. In this case only starting material was
isolated. This is not surprising, since it is known that to en-
hance the electrophilicity of the azomethine carbon, the
C]N of the imine has to be activated by coordination of
a Lewis acid with the nitrogen lone pair.18
Potassium organotrifluoroborates can be converted in situ
into the very electrophilic tricoordinate difluoroboranes29
using a Lewis acid activation. Common Lewis acids used
Table 1. Synthesis of 2,2-dichloroaldimines 2
Imine 2
R1
R2
Yielda (%)
2aa
2ab
2ac
2ad
2ae
2af
2ag
2be
2bf
2ce
Me
Me
Me
Me
Me
Me
Me
Et
Bn
86
88
70
66
t-Bu
i-Pr
n-Pr
Allyl
Et
84
56b
74c
47
Me
Allyl
Et
Allyl
Et
i-Pr
96
78d
Purity was sufficient for the next step (>92%, 1H NMR).
a
b
c
d
0 ꢀC.
ꢁ10 ꢀC.
Method b.

S. Stas, K. A. Tehrani / Tetrahedron 63 (2007) 8921–8931
8923
Table 2. Reaction between N-(2,2-dichloro-1-propylidene)amines 2a and potassium trifluoroborates
R2
R2
R3
1 equiv R3BF3K (4), CH2Cl2
N
HN
1 equiv BF3.OEt2
H
r.t., 18 h
Cl Cl
2a
Cl Cl
5
Entry (product)
R2 (2a)
R3 (4)
Unreacted
iminea (%)
Styrenea (%)
Product
Crude
Yield after
puritya,b (%)
yielda,b (%)
purificationb (%)
1 (5aa)
2 (5ga)
3 (5ab)
4 (5ac)
5 (5gc)
6 (5ad)
7 (5gd)
8 (5ae)
9 (5ge)
10 (5af)
11 (5bf)
12 (5cf)
13 (5ef)
14 (5gf)
15 (5ag)
16 (5hd)
17 (5id)
18 (5jd)
Bn (2aa)
Bn (2aa)
t-Bu (2ab)
i-Pr (2ac)
i-Pr (2ac)
n-Pr (2ad)
n-Pr (2ad)
Allyl (2ae)
Allyl (2ae)
Et (2af)
Et (2af)
Et (2af)
Et (2af)
Et (2af)
Me (2ag)
n-Pr (2ad)
n-Pr (2ad)
n-Pr (2ad)
PhCH]CH (a)
Ph-C^C (g)
PhCH]CH (a)
PhCH]CH (a)
Ph–C^C (g)
PhCH]CH (a)
Ph–C^C (g)
PhCH]CH (a)
Ph–C^C (g)
PhCH]CH (a)
47 (GC)
0
36 (GC)
8–24
0
52
0
0
19 (GC)
—
21 (GC)
2–25
—
11
—
0
—
7
3
23
—
—
18
0
34 (GC)
92
43 (GC)
67–73
92
37
95
100
99
66 (13)
48
59 (6)
80
100
24 (16)
99
99
24 (GC)
81
20 (GC)
21–37
72
27
78
44
83
32 (6)
60
23 (2)
30
80
20 (7)
88
90
—
—
9c
12d
—
36e
—
44e
—
0
13
48
12
20
0
28
0
0
26 (8)e,f
46e
16 (2)e,f
17g
80e
—
4-MeC6H4CH]CH (b)
4-ClC6H4CH]CH (c)
(Z)-MeCH]CH (e)
Ph–C^C (g)
PhCH]CH (a)
3-MeOC6H4C^C (h)
4-EtC6H4C^C (i)
MeOCH2C^C (j)
88e
90e
44e
0
0
0
99
44
Calculated from 1H NMR of the crude reaction mixture.
The number in brackets refers to the purity or yield of the double addition product.
After high vacuum distillation.
After acid–base extraction.
a
b
c
d
e
f
Evaporation of unreacted imine and styrene.
Yields calculated from the 1H NMR.
After flash chromatography (silica gel, Et2O/pentane, 1:9).
g
dramatically increased, probably because of the electron
richness of the alkynyl system (entries 2, 5, 7, 9, and 14).
Since this reaction proceeded more readily the functional-
ized propargylamines were obtained in satisfactory purity
(>92%) and hence needed no further purification. Elec-
tron-rich potassium phenylethynyltrifluoroborates 4h and i
even furnished the propargylic amines in higher yields and
purities (entries 16 and 17). The reaction was also extended
to aliphatic potassium (3-methoxypropynyl)trifluoroborate
(4j) (entry 18).
a lower yield of 3%. N-(4,4-Dichloro-1-phenylpent-1-
ene-3-yl)isopropylamine (5ac) was purified by an acid–
base extraction of the reaction mixture.
A number of experiments were conducted in order to
deduce the mode of reactivity of 4a in the presence of
imines. Non-aqueous work up of a mixture, which was
obtained by reaction of N-ethylimine 2af with trifluoro-
borate 4a and BF3$Et2O, by simple filtration and evapo-
ration of CH2Cl2 gave rise to an brown oil, which was
analyzed by NMR. The 1H NMR of this product was
shifted downfield compared to 5af, while in 19F NMR
a signal appeared at ꢁ131.87 ppm (CDCl3) and in 11B
NMR at ꢁ0.7 ppm (CDCl3). The solid, which was fil-
tered off prior to evaporation was shown to be KBF4
by comparison with an authentic sample. In accordance
with the literature and with our observations the reaction
mechanism of this Lewis acid-catalyzed Mannich reac-
tion starts with the formation of the very electrophilic
difluoroborane 6,16,29,33,34 which forms a complex with
the imine 2. The activated imino carbon atom of 7 will
now undergo an alkyl transfer to give primarily an
aminodifluoroborane 8. Upon basic aqueous work up,
the aminodifluoroborane 8 was converted to the desired
b,b-dichloroamine 5af (Scheme 3). Alternatively, BF3$Et2O
may form a complex with the aldimine 2af, which is
then susceptible for nucleophilic attack by the alkenyl-
trifluoroborate 4a.37 This hypothesis was, however, rejected
because of the immediate formation of difluoroboranes 6
and their much stronger Lewis acidity compared to
BF3$Et2O.38
In case potassium styryltrifluoroborate (4a) was used, also
varying amounts of styrene were observed as a side product.
In a model experiment, trifluoroborate 4a was reacted with
1 equiv of BF3$OEt2 in CH2Cl2 for 18 h. After evaporation
of the solvent, 1H NMR analysis showed the exclusive pres-
ence of styrene. On the other hand, simple basic treatment
(0.5 M NaOH) of 4a also induced hydrodeborylation. These
tests prove that next to the known acid deborylation,36 also
thermal or aqueous basic deborylation of potassium alkenyl-
trifluoroborates may occur.
The purification of the crude reaction mixtures occurred in
different ways, depending on the starting imine. The eas-
iest way to purify the mixture is to evaporate the formed
styrene and the unreacted imine, which was only possible
for volatile imines of 2,2-dichloropropanal (entries 6, 8,
10, 11, 12, and 14) and the reaction products from
alkynyltrifluoroborates 4g. N-(4,4-Dichloro-1-phenylpent-
1-ene-3-yl)-tert-butylamine (5ab) was purified by high
vacuum distillation because acid–base extraction gave

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S. Stas, K. A. Tehrani / Tetrahedron 63 (2007) 8921–8931
Table 3. Reaction between N-(2,2-dichloro-1-propylidene)amines 2a and
potassium trifluoroborates in CH2Cl2/HFIP
1 equiv R3BF3K (4)
1 equiv BF3.OEt2
CH2Cl2/HFIP (9 : 1)
R2
R2
R3
N
HN
H
r.t., 18 h
Cl Cl
2a
Cl Cl
5
Entry (product)
R2 (2a)
R3 (4)
Yielda (%)
1 (5aa)
2 (5aa)
3 (5ab)
4 (5ac)
5 (5ad)
6 (5ae)
7 (5af)
8 (5ag)
Bn
Bn
PhCH]CH
PhCH]CH
PhCH]CH
PhCH]CH
PhCH]CH
PhCH]CH
PhCH]CH
PhCH]CH
67
39b
64
62
74
73
68
69
t-Bu
i-Pr
n-Pr
Allyl
Et
Me
a
Isolated yields (purity >95% GC).
BF3$OEt2—2 equiv.
b
Scheme 3. Proposed reaction mechanism.
reaction. By using the more reactive potassium phenyl-
ethynyltrifluoroborate (4g) the same results were obtained
as when no HFIP was added. Potassium phenyltrifluoro-
borate, however, still did not react with the a,a-dichloro-
imines. In order to get some understanding of the function
of the co-solvent, other additives were also tested. Phenol,
which has a comparable pKa (10) as HFIP, led to the same
yields as without co-solvent. Addition of 2,2,3,3,4,4,5,5-
octafluoro-1-pentanol (pKa 11) even decreased the yield.
It was speculated that the use of HFIP as the sole solvent
might further accelerate the reaction. Reaction of imine
2ad with potassium styryltrifluoroborate (4a) in HFIP
leads to a disappointing 24% yield of the b,b-dichloro-
amine 5ad. If this reaction was repeated with potassium
phenylethynyltrifluoroborate (4g) a comparable yield of
82% was obtained as in a 9:1 CH2Cl2/HFIP solvent sys-
tem. In both cases the fluoroborate salts dissolved less
readily in HFIP, giving rise to sluggish reaction upon ad-
dition of BF3$Et2O. The lower yields and inferior purity
of the reaction products 5ad and 5gd in combination
with the high cost of HFIP justify its use as a co-solvent
with dichloromethane.
When the less sterically hindered N-ethyl- and N-methyl
imines of 2,2-dichloropropanal were reacted with potassium
styryltrifluoroborate (4a), the formation of a double addition
product 10 was observed (Scheme 4). This product was
formed due to the reaction of the intermediate aminodifluo-
roborane with the unreacted a,a-dichloroimine 2af or 2ag
still present in the reaction medium. Subsequent expulsion
of methylamine or ethylamine and addition of a styryl group
to the intermediate iminium ion then lead to 10. Despite
several efforts, the double addition product 10 could not be
separated from 9.
Scheme 4. Reagents and conditions: (i) PhCH]CHBF3K (4a, 1 equiv),
BF3$Et2O (1 equiv), CH2Cl2, rt, 18 h.
The reaction was expanded to a,a-dichloroimines 2b and 2c,
derived from other 2,2-dichloroalkanals (Table 4). The
In a recent paper, Nanda and Trotter claim that the classic
Petasis reaction can be accelerated using 1,1,1,3,3,3-hexa-
fluoroisopropanol (HFIP) as co-solvent. It is supposed that
the acidic HFIP accelerates the formation of the iminium
species, which may then be attacked by organoboronic
acids.39 Because of this precedent, we repeated the reaction
between an a,a-dichloroimine and a potassium trifluoro-
borate, with HFIP as co-solvent in dichloromethane (CH2Cl2/
HFIP, 9:1) (Table 3). All the yields fluctuate around 60–
70% for the BAM reactions with potassium styryltrifluoro-
borate (4a) when HFIP is used, which is much higher than
the same reaction in pure CH2Cl2. In all cases, the b,b-
dichloroamines 5 were of sufficient purity (>95%, GC)
so that no extra purification was required. Attempted column
chromatography of these products anyway resulted in big
losses (10–20% yield). The steric hindrance of the nitrogen
substituent does not play any role here and no double addi-
tion products are formed in the reactions with the ethylimine
2af and methylimine 2ag, probably because of the faster
Table 4. Reaction of other 2,2-dichloroaldimines with potassium styryl-
trifluoroborate
R2
H
1 equiv 4a
R2
N
1 equiv BF3.OEt2
CH2Cl2/HFIP (9 : 1)
HN
R1
Cl Cl
2b,c
R1
Cl Cl
11,12
Ph
18 h
Entry (product) R1 R2 Reaction conditions Puritya (%) Yielda,b (%)
1 (11af)
2 (11af)
3 (11ae)
4 (11ae)
5 (12ae)
6 (12ae)
Et Et
Et Et
Et Allyl Reflux
Et Allyl Pressure tube
i-Pr Allyl Reflux
i-Pr Allyl Pressure tube
Reflux
Pressure tube
64
67
58
87
38
62
33 (9)
21 (5)
50 (24)
29 (14)
22 (10)
28 (12)
Purity and crude yields were calculated from 1H NMR.
The number in brackets refers to the yield after acid–base extraction.
a
b

S. Stas, K. A. Tehrani / Tetrahedron 63 (2007) 8921–8931
8925
reaction with these imines was carried out under the
above-defined optimal conditions (equimolar reaction in
dichloromethane) with HFIP as co-solvent. However,
these imines did not undergo any reaction at room tem-
perature; therefore refluxing was required in order to in-
duce some conversion. In an attempt to further increase
the yield, the reaction was also carried out in a pressure
tube at 80 ꢀC. Under these circumstances no styrene was
formed and less unreacted imine was left, but the yield
of the reaction product remained very low. During these
pressure reactions also the aldehydes 1b and 1c were
formed, despite the dry conditions. Purification of the re-
action mixtures could be executed by a simple acid–base
extraction.
4.2. Synthesis of 2,2-dichloroaldimines; N-(2,2-dichloro-
1-propylidene)benzylamine (2aa); typical procedure
(method a)
To a stirred solution of 2,2-dichloropropanal (1a) (50 mmol,
6.35 g) in CH2Cl2 (50 mL) was added (150 mmol, 26.16 g)
MgSO4$3H2O as desiccant, followed by (47.5 mmol,
5.09 g) benzylamine. The solution was stirred under reflux
for 2 h. Afterward, the solution was filtered and concentrated
under reduced pressure. Yield: 9.33 g (86%), light-yellow
1
liquid. H NMR (250 MHz, CDCl3): d¼2.28 (s, 3H, CH3),
4.63 (s, 2H, CH2), 7.20–7.34 (m, 5H, Ph), 7.86 (t,
J¼1.4 Hz, 1H, HC]N). 13C NMR (62.90 MHz, CDCl3):
d¼32.5 (CH3), 62.5 (CH2), 84.6 (CCl2), 127.6 (CHarom.),
127.8 (CHarom.), 128.4 (CHarom.), 137.7 (Carom.quat.), 161.0
(C]N). MS (EI, 70 eV): m/z (%)¼219 (0.3) [M+4]+, 217
(3) [M+2]+, 215 (4) [M+], 182 (4), 180 (9), 144 (7), 118
(53), 104 (7), 92 (100), 89 (18), 77 (11), 75 (8), 65 (47),
63 (18), 62 (7), 61 (8), 51 (18), 50 (7). HRMS (ESI): m/z
calcd for C10H12NCl2+H: 216.0347; found: 216.0359. IR
3. Conclusion
In summary, we have developed a convenient new synthesis
of a stable new class of dichlorinated secondary propargyl-
amines and allylamines, by reaction of potassium arylethy-
nyltrifluoroborates and potassium styryltrifluoroborates
with a,a-dichlorinated aldimines in the presence of
BF3$OEt2 as a Lewis acid. The use of hexafluoroisopropanol
as a co-solvent in this reaction allows high yield isolation of
the pure target compounds.
(NaCl): 1667 (C]N), 1496 (C]C aromate) cmꢁ1
.
With volatile amines, 1.5 equiv was added instead of
0.95 equiv. The synthesis of imine 2ag takes place at 0 ꢀC
and imine 2ah at ꢁ10 ꢀC. Unless otherwise stated, 2,2-di-
chloroaldimines were synthesized on a 50 mmol scale.
4. Experimental
4.1. General
4.3. N-(2,2-Dichloro-3-methyl-1-butylidene)allylamine
(2ce) (method b)
In a three-necked flask (100 mL), provided with a condenser
and a CaCl2 tube, was added a 20% solution of 2,2-dichloro-
3-methylbutanal (1c) (30 mmol, 4.65 g) in dry Et2O
(23 mL). After cooling this solution to 0 ꢀC, TiCl4
(18 mmol, 2 mL) in dry pentane (5 mL) was added dropwise.
Under vigorous stirring, allylamine (0.12 mol, 6.85 g) was
added dropwise to this mixture at 0 ꢀC. The reaction was
stirred for another 2 h at room temperature before the workup.
The mixture was poured into aqueous NaOH (0.5 M, 40 mL)
andquicklyextractedwithEt2O(3ꢂ30 mL). Theorganicfrac-
tions were combined, dried (K2CO3), and concentrated under
reduced pressure. Yield: 4.50 g (78%, 30 mmol), light-yellow
GC–MS analyses were performed using an Intersience GC
8000 series gas chromatograph with an ECÔ-5 column
(length: 30 m, internal diameter: 0.32 mm, film thickness:
0.25 mm). Products are injected in a split injector (250 ꢀC);
the inert carrier gas is helium. The mass spectrometer is a Fi-
sons Instruments MD 800 using electron impact (70 eV) as
ionization method. HRMS was measured with a VGQuattro
II mass spectrometer (positive ion mode). Under our stan-
dard measurement conditions the sample was dissolved
in CH3CN/H2O (1:1) containing 0.1% TFA. In order to
avoid eventual hydrolysis, the imines 2 were dissolved
in CH3CN/MeOH (1:1). High resolution 1H NMR
(250 MHz), 13C NMR (62.90 MHz), and 19F NMR
(235.3 MHz) spectra were recorded in CDCl3 or DMSO-d6
on a Bruker Avance DRX 250 spectrometer. 11B NMR
(160.5 MHz) spectra were recorded on a Bruker Avance II
500 spectrometer. Chemical shifts are reported in parts per
million downfield from TMS. 13C NMR assignments were
made using DEPT, HMQC and HMBC spectra. Infrared
spectra were recorded with an Avatar 370 FTIR apparatus
(Thermo Nicolet). Unless otherwise stated, the IR spectra
were recorded using the attenuated total reflection technol-
ogy. Flash chromatography was performed using Merck
silica (diameter 40–63 mm). TLC analysis was performed
on glass backed plates (Merck) coated with 0.2 mm silica
with UV-indicator 60F254. 2,2-Dichloroaldehydes 1 were
prepared by halogenation of the corresponding aldehydes
or alcohols with chlorine gas in the presence of tetraalkylam-
monium chlorides.28 Potassium trifluoroborates 4a,40 4b,16
4d,41 4f,29 4g,42 and 4j43 and potassium 4-methoxyphenyl-
trifluoroborate44 were prepared according to the literature
procedures.
1
liquid. H NMR (250 MHz, CDCl3): d¼1.18 (d, J¼6.6 Hz,
2ꢂ3H, (CH3)2CH), 2.64 (septet, J¼6.7 Hz, 1H, (CH3)2CH),
4.17–4.21 (m, 2H, CH2CH]CH2), 5.13–5.24 (m, 2H,
CH2CH]CH2), 5.90–6.06 (m, 1H, CH2CH]CH2), 7.72 (t,
J¼1.4 Hz, 1H, HC]N). 13C NMR (62.90 MHz, CDCl3):
d¼18.1 ((CH3)2CH), 40.3 ((CH3)2CH), 61.6 (CH2CH]CH2),
94.5 (CCl2), 117.0 (CH2CH]CH2), 134.4 (CH2CH]CH2),
161.3 (C]N). MS (EI, 70 eV): m/z (%)¼198 (0.32)
[M+5]+, 196 (2) [M+3]+, 194 (3.5) [M+H+], 158 (29), 153
(16), 151 (26), 125 (15), 124 (13), 118 (20), 116 (44), 102
(20), 91 (20), 89 (42), 83 (75), 81 (14), 80 (39), 75 (22), 68
(100), 65 (22), 63 (27), 55 (22), 54 (14), 53 (51), 51 (38).
HRMS (ESI): m/z calcd for C8H14NCl2+H: 194.0503; found:
194.0446. IR (ATR): 1666 (C]N), 1461, 1445 (C]C) cmꢁ1
.
4.3.1. N-(2,2-Dichloro-1-propylidene)-tert-butylamine
(2ab). Yield: 7.98 g (88%), light-yellow liquid. Spectral
data were in accordance with the literature.45
4.3.2. N-(2,2-Dichloro-1-propylidene)isopropylamine
(2ac). Yield: 5.86 g (70%), colorless liquid; bp¼27–31 ꢀC/

8926
S. Stas, K. A. Tehrani / Tetrahedron 63 (2007) 8921–8931
17 Torr. 1H NMR (250 MHz, CDCl3): d¼1.19 (d, J¼6.3 Hz,
6H, CH(CH3)2), 2.27 (s, 3H, CH3CCl2), 3.50 (septet,
J¼6.3 Hz, 1H, CH(CH3)2), 7.77 (s, 1H, HC]N). 13C
NMR (62.90 MHz, CDCl3): d¼23.5 (CH(CH3)2), 32.6
(CH3CCl2), 59.6 (CH(CH3)2), 84.9 (CCl2), 157.6 (C]N).
MS (EI, 70 eV): m/z (%)¼171 (0.01) [M+4]+, 169 (0.02)
[M+2]+, 167 (0.03) [M+], 152 (1), 105 (8), 104 (100), 103
(48), 102 (9), 78 (50), 77 (24), 70 (32), 63 (10), 52 (8), 51
(24), 50 (11). HRMS (ESI): m/z calcd for C6H12NCl2+H:
(100), 102 (23), 97 (16), 75 (22), 68 (64), 66 (26), 64 (17),
63 (50), 62 (36), 61 (61), 60 (21), 54 (15), 52 (42), 51
(38). HRMS (ESI): m/z calcd for C4H8NCl2+H: 140.0034;
found: 140.0029. IR (NaCl): 1673 (C]N) cmꢁ1
.
4.3.7. N-(2,2-Dichloro-1-butylidene)allylamine (2be).
Yield: 420 mg (47%, 5 mmol), light-yellow liquid. 1H
NMR (250 MHz, CDCl3): d¼1.23 (t, J¼7.2 Hz, 3H, CH3),
2.46 (q, J¼7.2 Hz, 2H, CH3CH2CCl2), 4.14–4.17 (m, 2H,
CH2–CH]CH2), 5.11–5.22 (m, 2H, CH2–CH]CH2),
5.90–6.05 (m, 1H, CH2–CH]CH2), 7.78 (s, 1H, HC]N).
13C NMR (62.90 MHz, CDCl3): d¼9.5 (CH3), 37.0
(CH2CCl2), 61.3 (CH2CH]CH2), 90.0 (CCl2), 116.9
(CH2–CH]CH2), 134.4 (CH2CH]CH2), 161.1 (C]N).
MS (EI, 70 eV): m/z (%)¼184 (0.21) [M+5]+, 182 (1.5)
[M+3]+, 180 (2) [M+H+], 146 (8), 144 (24), 116 (19), 113
(18), 111 (28), 108 (13), 102 (10), 83 (47), 77 (23), 75
(47), 68 (100), 54 (9), 53 (26), 52 (10), 51 (21). HRMS
(ESI): m/z calcd for C7H12NCl2+H: 180.0347; found:
180.0355. IR (ATR): 1665 (C]N), 1456, 1428 (C]C)
168.0347; found: 168.0340. IR (NaCl): 1664 (C]N) cmꢁ1
.
4.3.3. N-(2,2-Dichloro-1-propylidene)propylamine (2ad).
Yield: 5.55 g (66%), yellow liquid. H NMR (250 MHz,
1
CDCl3): d¼0.91 (t, J¼7.4 Hz, 3H, CH2CH3), 1.66 (sextet,
J¼7.2 Hz, 2H, NCH2CH2CH3), 2.28 (s, 3H, CH3CCl2),
3.47 (td, J¼6.8, 1.0 Hz, 2H, NCH2), 7.77 (t, J¼1.2 Hz,
1H, HC]N). 13C NMR (62.90 MHz, CDCl3): d¼11.6
(CH2CH3), 23.4 (NCH2CH2CH3), 32.6 (CH3CCl2), 61.1
(NCH2), 84.6 (CCl2), 160.1 (C]N). MS (EI, 70 eV): m/z
(%)¼172 (1) [M+5]+, 170 (3) [M+3]+, 168 (4) [M+H+],
140 (12), 138 (19), 134 (21), 132 (47), 109 (12), 104 (18),
103 (10), 102 (41), 99 (12), 97 (22), 92 (20), 90 (49), 75
(33), 70 (100), 68 (37), 67 (15), 63 (26), 62 (13), 61 (33),
54 (36), 52 (16), 51 (20). HRMS (ESI): m/z calcd for
C6H12NCl2+H: 168.0347; found: 168.0345. IR (NaCl):
cmꢁ1
.
4.3.8. N-(2,2-Dichloro-1-butylidene)ethylamine (2bf).
Yield: 807 mg (96%, 5 mmol), light-yellow liquid. 1H
NMR (250 MHz, CDCl3): d¼1.22 (t, J¼7.2 Hz, 3H,
CH3CH2CCl2), 1.24 (t, J¼7.3 Hz, 3H, NCH2CH3), 2.44
(q, J¼7.2 Hz, 2H, CH2CCl2), 3.55 (qd, J¼7.3, 1.3 Hz,
2H, NCH2CH3), 7.76 (t, J¼1.3 Hz, 1H, HC]N). 13C
NMR (62.90 MHz, CDCl3): d¼9.5 (CH3CH2CCl2), 15.6
(NCH2CH3), 37.1 (CH2CCl2), 54.0 (NCH2), 87.7 (CCl2),
159.6 (C]N). MS (EI, 70 eV): m/z (%)¼170 (0.2)
[M+5]+, 168 (0.3) [M+3]+, 166 (0.04) [M+H+], 134 (6),
132 (17), 104 (7), 77 (6), 75 (19), 71 (17), 68 (7), 61 (7),
58 (10), 56 (100), 54 (6), 53 (12), 51 (15). HRMS (ESI):
m/z calcd for C6H12NCl2+H: 168.0347; found: 168.0340.
1669 (C]N) cmꢁ1
.
4.3.4. N-(2,2-Dichloro-1-propylidene)allylamine (2ae).
Yield: 6.95 g (84%), light-yellow liquid. 1H NMR
(250 MHz, CDCl3): d¼2.29 (s, 3H, CH3), 4.13–4.17 (m,
2H, NCH2), 5.15–5.23 (m, 2H, CH2CH]CH2), 5.89–6.05
(m, 1H, CH2CH]CH2), 7.80 (t, J¼1.3 Hz, 1H, HC]N).
13C NMR (62.90 MHz, CDCl3): d¼32.5 (CH3), 60.9
(CH2CH]CH2), 84.4 (CCl2), 116.9 (CH2CH]CH2),
134.2 (CH2CH]CH2), 161.0 (C]N). MS (EI, 70 eV):
m/z (%)¼170 (1) [M+5]+, 168 (8) [M+3]+, 166 (12)
[M+H+], 132 (31), 130 (46), 104 (13), 102 (34), 101 (18),
99 (43), 97 (49), 94 (37), 77 (15), 76 (13), 75 (41), 68
(100), 66 (13), 65 (16), 64 (14), 63 (29), 62 (28), 61 (49),
54 (33), 53 (11), 52 (28), 51 (30). HRMS (ESI): m/z calcd
for C6H10NCl2+H: 166.0190; found: 166.0197. IR (ATR):
IR (ATR): 1664 (C]N) cmꢁ1
.
4.4. Synthesis of the potassium trifluoroborates
These compounds were prepared analogously to published
methods.13 Since no spectra have been reported for these
compounds, they are given here.
1668 (C]N), 1438, 1380 (C]C) cmꢁ1
.
4.3.5. N-(2,2-Dichloro-1-propylidene)ethylamine (2af).
Yield: 4.31 g (56%), colorless liquid; bp¼36 ꢀC/20 Torr.
1H NMR (250 MHz, CDCl3): d¼1.24 (t, J¼7.3 Hz, 3H,
NCH2CH3), 2.27 (s, 3H, CH3CCl2), 3.55 (q, J¼7.3 Hz,
2H, NCH2), 7.78 (t, J¼1.3 Hz, 1H, HC]N). 13C NMR
(62.90 MHz, CDCl3): d¼15.5 (NCH2CH3), 32.6 (CH3CCl2),
53.7 (NCH2), 84.7 (CCl2), 159.6 (C]N). MS (EI, 70 eV):
m/z (%)¼158 (2) [M+5]+, 156 (16) [M+3]+, 154 (23)
[M+H+], 120 (42), 118 (50), 102 (36), 99 (31), 97 (40), 90
(48), 75 (33), 63 (36), 62 (31), 61 (36), 56 (100), 54 (38),
52 (31), 51 (35). HRMS (ESI): m/z calcd for C5H10NCl2+H:
4.4.1. Potassium 2,5-dimethoxyphenyltrifluoroborate.
Yield: 2.68 g (89%, 11 mmol), white solid; mp >260 ꢀC.
1H NMR (250 MHz, DMSO): d¼3.55 and 3.61 (2ꢂs,
2ꢂ3H, 2ꢂMe), 6.50–6.60 (m, 2H, CHmeta+para), 6.85 (d,
J¼2.7 Hz, 1H, CHortho). 13C NMR (62.90 MHz, DMSO):
d¼55.3 and 56.1 (2ꢂMe), 111.0 and 111.4 (Carom.meta
+
Carom.para), 119.4 (q, J¼3.2 Hz, CHarom.ortho), 153.0 (Carom.quat.
OMemeta), 157.1 (q, J¼0.7 Hz, Carom.quat.OMeortho), Carom.quat.
B was not visible. IR (ATR): 1490, 1468, 1399 (C]C) cmꢁ1
.
4.4.2. Potassium (E)-2-(4-chlorophenyl)vinyltrifluorobo-
rate (4c). Yield: 440 mg (66%, 2.7 mmol), white solid; mp
>260 ꢀC. 1H NMR (250 MHz, DMSO): d¼6.19 (dq,
J¼14.8, 3.3 Hz, 1H, CH]CHB), 6.44 (d, J¼18.3 Hz, 1H,
CH]CHB), 7.27 (d, J¼8.6 Hz, 2H, (CH)2Carom.quat.
CH]CH), 7.33 (d, J¼8.6 Hz, 2H, ClCarom.quat.(CH)2). 13C
NMR (62.90 MHz, DMSO): d¼126.9 ((CH)2Carom.quat.CH),
128.1 (ClCarom.quat.(CH)2), 129.9 (Carom.quat.CH), 131.6 (q,
J¼4.4 Hz, CH]CHB), 139.1 (Carom.quat.Cl), CH]CHB
was not visible. 11B NMR (160.5 MHz, DMSO, B(OMe)3
154.0190; found: 154.0201. IR (NaCl): 1668 (C]N) cmꢁ1
.
4.3.6. N-(2,2-Dichloro-1-propylidene)methylamine (2ag).
Yield: 5.15 g (74%), yellow liquid. H NMR (250 MHz,
1
CDCl3): d¼2.26 (s, 3H, NCH3), 3.40 (s, 3H, CH3CCl2),
7.78 (t, J¼1.5 Hz, 1H, HC]N). 13C NMR (62.90 MHz,
CDCl3): d¼32.5 (NCH3), 45.7 (CH3CCl2), 84.4 (CCl2),
161.5 (C]N). MS (EI, 70 eV): m/z (%)¼144 (1) [M+5]+,
142 (7) [M+3]+, 140 (14) [M+H+], 124 (3), 106 (73), 104

S. Stas, K. A. Tehrani / Tetrahedron 63 (2007) 8921–8931
8927
external standard): d¼2.4 (s). 19F NMR (235.3 MHz,
DMSO): d¼ꢁ138.4 (s). IR (ATR): 1624, 1589, 1564,
(CHNH), 92.9 (CCl2), 126.7 (CH]CHPh), 127.1
(CH]CHCarom.quat.), 127.6 (HCarom.para(styryl)), 128.1
(HCarom.para (benzyl)), 127.2 and 128.3 (HCarom.ortho+meta
(styryl)), 128.5 and 128.7 (HCarom.ortho+meta(benzyl)), 129.1
(CH2Carom.quat.), 135.6 (CH]CHPh). MS (EI, 70 eV): m/z
(%)¼323 (trace) [M+4]+, 321 (trace) [M+2]+, 319 (0.02)
[M+], 249 (15), 247 (55), 223 (100), 158 (14), 156 (39),
130 (22), 128 (37), 115 (32), 91 (77), 77 (20), 65 (33).
HRMS (ESI): m/z calcd for C18H20NCl2+H: 320.0973;
found: 320.0965. IR (ATR): 3335 (NH), 1494, 1449
1488, 1402 (C]C) cmꢁ1
.
4.4.3. Potassium (Z)-propenyltrifluoroborate (4e). Yield:
1
206 mg (24%, 5.8 mmol), white solid; mp >260 ꢀC. H
NMR (250 MHz, DMSO): d¼1.60 (d, J¼6.5 Hz, 3H,
CH3), 5.15 (dq, J¼3.6, 1.7 Hz, 1H, CH3CH), 5.21 (dq,
J¼3.7, 1.7 Hz, 1H, CHB). 13C NMR (62.90 MHz,
DMSO): d¼17.0 (CH3), 129.0 (q, J¼4.1 Hz, CH3CH),
CHB was not visible. 11B NMR (160.5 MHz, DMSO,
B(OMe)3 external standard): d¼2.4 (q, J¼175.5 Hz). 19F
(235.3 MHz, DMSO): d¼ꢁ132.6 (q, J¼59.6 Hz). IR
(C]C), 1373 (HC]CH) cmꢁ1
.
4.5.2. N-(4,4-Dichloro-1-phenylpent-1-yne-3-yl)benzyl-
amine (5ga). Yield: 129 mg (81%), yellow oil. H NMR
(ATR): 1633, 1404 (HC]CH) cmꢁ1
.
1
(250 MHz, CDCl3): d¼1.95 (s, 1H, NH), 2.27 (s, 3H,
CH3), 3.88 (s, 1H, CHNH), 4.00 and 4.21 (2ꢂd,
J¼13.3 Hz, 2H, CH2), 7.55–7.24 (m, 10H, 2ꢂPh). 13C
NMR (62.90 MHz, CDCl3 internal standard, assignment
by HMQC, HMBC and COSY): d¼34.8 (CH3), 52.0
(NHCH2), 63.4 (CHNH), 86.2 (C^CPh), 86.7 (C^CPh),
91.5 (CCl2), 122.9 (C^CCarom.quat.), 128.8 and 128.9
(2ꢂHCarom.meta), 127.7 and 129.0 (2ꢂHCarom.para), 128.7
and 132.3 (2ꢂHCarom.ortho), 139.5 (CH2Carom.quat.). MS
(EI, 70 eV): m/z (%)¼322 (0.03) [M+5]+, 320 (0.08)
[M+3]+, 318 (0.10) [M+H+], 220 (100), 204 (10), 193
(14), 178 (15), 142 (25), 141 (12), 139 (25), 129 (26), 128
(16), 115 (56), 113 (14), 102 (46), 99 (11), 97 (14), 91
(89), 89 (32), 78 (27), 77 (13), 76 (10), 74 (10), 65 (50),
63 (26), 61 (10), 51 (19). HRMS (ESI): m/z calcd for
C18H18NCl2+H: 318.0816; found: 318.0826. IR (ATR):
4.4.4. Potassium (3-methoxyphenyl)ethynyltrifluorobo-
1
rate (4h). Yield 32%, colorless crystals; mp >250 ꢀC. H
NMR (250 MHz, DMSO-d6): d 3.72 (s, 3H, CH3), 6.7–6.9
(m, 3H, Ar), 7.1–7.3 (m, 1H, Ar). 13C NMR (62.90 MHz,
DMSO): d 60.2 (d, J¼0.6 Hz, CH3), 118.4 (CAr), 121.1 (d,
J¼0.9 Hz, CAr), 128.6 (d, J¼0.8 Hz, CAr), 131.8 (d,
J¼0.7 Hz, CAr–C^C), 134.6 (CAr), 164.2 (CAr–OCH3). IR
(ATR): 2184 (C^C) cmꢁ1
.
4.4.5. Potassium (4-ethylphenyl)ethynyltrifluoroborate
1
(4i). Yield 60%, colorless crystals; mp >250 ꢀC. H NMR
(250 MHz, DMSO): d 1.09 (t, J¼7.6 Hz, 3H, CH3), 2.51
(q, J¼7.6 Hz, 2H, CH2), 7.05 (pseudo d, J¼8.2 Hz, 2H,
Ar), 7.14 (pseudo d, J¼8.2 Hz, 2H, Ar). 13C NMR
(62.9 MHz, DMSO): d 15.3 (CH3), 27.9 (CH2), 122.7
(CAr–C^C), 127.6, 130.9, 142.3 (CAr–Et). IR (ATR):
1489, 1455, 1443 (C]C) cmꢁ1
.
2181 (C^C) cmꢁ1
.
4.5.3. N-(4,4-Dichloro-1-phenylpent-1-ene-3-yl)-tert-bu-
tylamine (5ab). Yield: 92 mg (64%), yellow oil; bp 29 ꢀC/
1.9 Torr. 1H NMR (250 MHz, CDCl3): d¼1.14 (s, 9H,
C(CH3)3), 2.19 (s, 3H, CH3CCl2), 3.63 (d, J¼8.1 Hz, 1H,
CHNH), 6.21 (dd, J¼16.0, 8.1 Hz, 1H, CH]CHPh), 6.55
(d, J¼16.0 Hz, 1H, CH]CHPh), 7.23–7.43 (m, 5H, Ph).
13C NMR (62.90 MHz, CDCl3): d¼30.5 (C(CH3)3), 35.1
(CH3CCl2), 51.4 (C(CH3)3), 67.3 (CHNH), 94.6 (CCl2),
127.8 (HCarom.para), 126.5 and 128.6 (HCarom.ortho+meta),
130.1 (CH]CHPh), 133.8 (CH]CHPh), 136.7 (Carom.quat.).
MS (EI, 70 eV): m/z (%)¼289 (trace) [M+4]+, 287 [M+2]+,
285 (0.01) [M+], 274 (0.13), 272 (1), 270 (2), 188 (85), 177
(26), 158 (15), 143 (13), 142 (27), 141 (26), 133 (11), 132
(100), 130 (21), 128 (16), 115 (55), 91 (13), 77 (13), 57
(32). HRMS (ESI): m/z calcd for C15H21NCl2+H:
286.1129; found: 286.1063. IR (ATR): 1494, 1448 (C]C),
4.5. Synthesis of the b,b-dichloroamines 5; general
procedure
To a stirred solution of a,a-dichloroaldimine 2 (1 equiv) in
CH2Cl2 (8 mL) was added the potassium trifluoroborate 4
(1 equiv) in one portion, followed by BF3$Et2O (1 equiv).
The reaction mixture was stirred for 18 h at room tempera-
ture and poured into aqueous NaOH (0.5 M). After isolation
of the organic layer, the aqueous phase was washed with
CH2Cl2 (4ꢂ15 mL). The organic fractions were dried
(MgSO4) and concentrated under reduced pressure.
The reactions with trifluoroborate 4a were carried out in
CH2Cl2/HFIP (9:1). Unless otherwise stated, the yields
described below for the a-alkenyl-b,b-dichloroamines are
from the reactions with HFIP as co-solvent and the yields
for the a-alkynyl-b,b-dichloroamines are from the reactions
without HFIP.
1365 (HC]CH) cmꢁ1
.
4.5.4. N-(4,4-Dichloro-1-phenylpent-1-ene-3-yl)isopro-
pylamine (5ac). Yield: 84 mg (62%), yellow oil. H NMR
1
Unless otherwise stated, all these reactions were performed
on a 0.5 mmol scale.
(250 MHz, CDCl3): d¼1.06 and 1.09 (2ꢂd, J¼6.2 Hz, 6H,
CH(CH3)2), 2.18 (s, 3H, CH3CCl2), 2.89 (septet,
J¼6.2 Hz, 1H, CH(CH3)2), 3.49 (d, J¼8.4 Hz, 1H,
CHNH), 6.14 (dd, J¼15.9, 8.4 Hz, 1H, CH]CHPh), 6.55
(d, J¼15.9 Hz, 1H, CH]CHPh), 7.22–7.44 (m, 5H,
Ph). 13C NMR (62.90 MHz, CDCl3): d¼22.1 and
24.2 (CH(CH3)2), 35.0 (CH3CCl2), 45.8 (CH(CH3)2),
70.2 (CHNH), 93.4 (CCl2), 126.8 (CH]CHPh), 127.9
(HCarom.para), 126.6 and 128.6 (HCarom.ortho+meta), 134.2
(CH]CHCarom.quat.), 136.4 (Carom.quat.). MS (EI, 70 eV):
m/z (%)¼275 (trace) [M+4]+, 273 (trace) [M+2]+, 271
4.5.1. N-(4,4-Dichloro-1-phenylpent-1-ene-3-yl)benzyl-
amine (5aa). Yield: 108 mg (67%), yellow oil. H NMR
1
(250 MHz, CDCl3): d¼2.18 (s, 3H, CH3), 3.43 (d,
J¼8.6 Hz, 1H, CHNH), 3.75 and 4.02 (2ꢂd, J¼13.6 Hz,
2H, CH2), 6.16 (dd, J¼15.9, 8.6 Hz, 1H, CH]CHPh),
6.52 (d, J¼15.9 Hz, 1H, CH]CHPh), 7.23–7.45 (m, 10H,
2ꢂPh). 13C NMR (62.90 MHz, CDCl3, assignment by
HMQC and HMBC): d¼34.9 (CH3), 50.8 (CH2), 71.2

8928
S. Stas, K. A. Tehrani / Tetrahedron 63 (2007) 8921–8931
(0.01) [M+], 238 (0.2), 236 (1), 177 (18), 175 (100), 158 (18),
143 (23), 142 (29), 141 (36), 132 (58), 130 (38), 128 (42),
117 (15), 116 (16), 115 (56), 91 (26), 77 (26). HRMS
(ESI): m/z calcd for C14H19NCl2+H: 272.0973; found:
272.0974. IR (NaCl): 3324 (NH), 1495, 1448 (C]C),
C14H17NCl2+H: 270.0816; found: 270.0696. IR (ATR):
1489, 1458, 1443 (C]C) cmꢁ1
.
4.5.8. N-(4,4-Dichloro-1-phenylpent-1-ene-3-yl)allyl-
amine (5ae). Yield: 99 mg (73%), yellow oil. H NMR
1
1339 (HC]CH) cmꢁ1
.
(250 MHz, CDCl3): d¼2.19 (s, 3H, CH3), 3.20 (ddt,
J¼14.2, 6.8, 1.2 Hz, 1H, (H)CHCH]CH2), 3.43 (ddt,
J¼14.2, 5.1, 1.6 Hz, 1H, (H)CHCH]CH2), 3.50 (d, J¼
8.6 Hz, 1H, CHNH), 5.11–5.26 (m, 2H, CH2CH]CH2),
5.81–5.97 (m, 1H, CH2CH]CH2), 6.10 (dd, J¼15.9,
8.6 Hz, 1H, CH]CHPh), 6.56 (d, J¼15.9 Hz, 1H,
CH]CHPh), 7.24–7.50 (m, 5H, Ph). 13C NMR
(62.90 MHz, CDCl3): d¼34.9 (CH3), 49.6 (CH2CH]CH2),
71.5 (CHNH), 93.0 (CCl2), 116.6 (CH2CH]CH2),
125.9 (CH]CHPh), 128.1 (HCarom.para), 126.6 and 128.7
(HCarom.ortho+meta), 135.4 (CH]CHPh), 136.2 (Carom.quat.),
136.5 (CH2CH]CH2). MS (EI, 70 eV): m/z (%)¼273
(0.02) [M+4]+, 271 (0.02) [M+2]+, 269 (0.02) [M+], 172
(100), 156 (13), 144 (16), 143 (15), 141 (29), 130 (67),
128 (52), 117 (13), 116 (12), 115 (79), 103 (18), 102 (17),
101 (11), 99 (36), 97 (57), 94 (13), 91 (36), 89 (15), 80 (12),
78 (10), 77 (43), 65 (11), 63 (31), 61 (34), 54 (26), 51 (24).
HRMS (ESI): m/z calcd for C14H17NCl2+H: 270.0816;
found: 270.0706. IR (ATR): 3322 (NH), 1494, 1448
4.5.5. N-(4,4-Dichloro-1-phenylpent-1-yne-3-yl)isopro-
pylamine (5gc). Yield: 97 mg (72%), yellow oil. H NMR
1
(250 MHz, CDCl3): d¼1.09 and 1.18 (2ꢂd, J¼6.2 Hz, 6H,
CH(CH3)2), 2.28 (s, 3H, CH3CCl2), 3.20 (septet,
J¼6.2 Hz, 1H, CH(CH3)2), 3.94 (s, 1H, CCl2CH), 7.24–
7.35 (m, 3H, CHarom.meta+CHarom.para), 7.41–7.51 (m, 2H,
CHarom.ortho). 13C NMR (62.90 MHz, CDCl3): d¼22.0 and
24.0 (CH(CH3)2), 34.3 (CH3CCl2), 47.2 (CH(CH3)2), 62.0
(CCl2CH), 85.4 (C^CPh), 86.8 (C^CPh), 91.4 (CCl2),
122.6 (Carom.quat.), 128.4 (HCarom.para), 128.3 (HCarom.meta),
131.8 (HCarom.ortho). MS (EI, 70 eV): m/z (%)¼274 (0.03)
[M+5]+, 272 (0.23) [M+3]+, 270 (0.66) [M+H+], 177 (23),
176 (30), 172 (100), 158 (12), 156 (33), 142 (32), 141
(14), 139 (36), 132 (13), 130 (70), 129 (31), 128 (21), 126
(13), 115 (59), 113 (20), 103 (80), 99 (16), 97 (20), 77
(49), 74 (13), 63 (27), 61 (13). HRMS (ESI): m/z calcd for
C14H17NCl2+H: 270.0816; found: 270.0686. IR (ATR):
1489, 1442 (C]C) cmꢁ1
.
(C]C aromate), 1376 (HC]CH and CH]CH2) cmꢁ1
.
4.5.6. N-(4,4-Dichloro-1-phenylpent-1-ene-3-yl)propyl-
amine (5ad). Yield: 101 mg (74%), yellow oil. H NMR
4.5.9. N-(4,4-Dichloro-1-phenylpent-1-yne-3-yl)allyl-
amine (5ge). Yield: 111 mg (83%), yellow oil. H NMR
1
1
(250 MHz, CDCl3): d¼0.93 (t, J¼7.4 Hz, 3H, CH2CH3),
1.52 (sextet, J¼7.2 Hz, 2H, CH2CH2CH3), 2.19 (s, 3H,
CH3CCl2), 2.47–2.57 (m, 1H, (H)CHCH2CH3), 2.66–2.76
(m, 1H, (H)CHCH2CH3), 3.44 (d, J¼8.5 Hz, 1H, CHNH),
6.12 (dd, J¼15.9, 8.5 Hz, 1H, CH]CHPh), 6.58 (d,
J¼15.9 Hz, 1H, CH]CHPh), 7.23–7.47 (m, 5H, Ph). 13C
NMR (62.90 MHz, CDCl3): d¼11.7 (CH2CH3), 23.1
(CH2CH3), 34.8 (CH3CCl2), 49.4 (NHCH2), 72.8 (CHNH),
93.1 (CCl2), 126.5 (CH]CHPh), 128.0 (HCarom.para),
126.6 and 128.7 (HCarom.ortho+meta), 134.9 (CH]CHPh),
136.3 (Carom.quat.). MS (EI, 70 eV): m/z (%)¼276 (0.01)
[M+5]+, 274 (0.01) [M+3]+, 272 (0.06) [M+H+], 200 (12),
177 (15), 175 (100), 144 (14), 143 (22), 142 (30), 141
(34), 132 (33), 130 (26), 128 (34), 127 (12), 117 (20), 116
(13), 115 (53), 103 (13), 99 (10), 97 (12), 91 (37), 77 (24),
68 (11), 63 (10), 56 (11), 51 (11). HRMS (ESI): m/z calcd
for C14H19NCl2+H: 272.0973; found: 272.0864. IR (ATR):
(250 MHz, CDCl3): d¼2.29 (s, 3H, CH3CCl2), 3.44 (ddt,
J¼14.0, 6.7, 1.2 Hz, 1H, (H)CHCH]CH2), 3.65 (ddt,
J¼14.0, 5.3, 1.5 Hz, 1H, (H)CHCH]CH2), 3.95 (s, 1H,
CHNH), 5.14–5.35 (m, 2H, CH2CH]CH2), 5.85–5.99 (m,
1H, CH2CH]CH2), 7.25–7.31 (m, 3H, CHarom.meta+para),
7.42–7.51 (m, 2H, CHarom.ortho). 13C NMR (62.90 MHz,
CDCl3): d¼34.3 (CH3CCl2), 50.4 (CH2CH]CH2),
63.1 (CHNH), 85.9 (C^CPh), 86.1 (C^CPh), 91.1
(CCl2), 117.2 (CH2CH]CH2), 122.4 (Carom.quat.), 128.3
(HCarom.meta), 128.6 (HCarom.para), 131.8 (HCarom.ortho),
135.9 (CH2CH]CH2). MS (EI, 70 eV): m/z (%)¼272
(0.01) [M+5]+, 270 (0.03) [M+3]+, 268 (0.04) [M+H+],
172 (31), 170 (98), 141 (41), 139 (24), 130 (13), 128
(100), 116 (52), 115 (24), 113 (14), 104 (19), 103 (22), 99
(13), 97 (16), 91 (16), 78 (17), 77 (12), 65 (13), 63 (18),
61 (12), 51 (12). HRMS (ESI): m/z calcd for C14H15NCl2+H:
268.0660; found: 268.0587. IR (ATR): 1489, 1443 (C]C),
3309 (NH), 1494, 1448 (C]C), 1377 (HC]CH) cmꢁ1
.
1375, 1290 (CH]CH2) cmꢁ1
.
4.5.7. N-(4,4-Dichloro-1-phenylpent-1-yne-3-yl)propyl-
amine (5gd). Yield: 105 mg (78%), yellow oil. H NMR
4.5.10. N-(4,4-Dichloro-1-phenylpent-1-ene-3-yl)ethyl-
amine (5af). Yield: 88 mg (68%), yellow oil. 1H NMR
(250 MHz, CDCl3): d¼1.14 (t, J¼7.1 Hz, 3H, CH2CH3),
2.19 (s, 3H, CH3CCl2), 2.60 and 2.80 (2ꢂdq, J¼11.5,
7.2 Hz, 2H, CH2CH3), 3.46 (d, J¼8.9 Hz, 1H, CHNH),
6.12 (dd, J¼15.9, 8.5 Hz, 1H, CH]CHPh), 6.58 (d,
J¼15.9 Hz, 1H, CH]CHPh), 7.25–7.46 (m, 5H, Ph).
13C NMR (62.90 MHz, CDCl3, assignment by HMQC
and HMBC): d¼15.2 (CH2CH3), 34.8 (CH3CCl2),
41.8 (CH2CH3), 72.8 (CHNH), 93.0 (CCl2), 126.5 (CH]
CHPh), 126.6 (HCarom.meta), 128.0 (HCarom.para), 128.7
(HCarom.ortho), 134.9 (CH]CHPh), 136.3 (Carom.quat.). MS
(EI, 70 eV): m/z (%)¼261 (0.03) [M++4], 259 (0.05) [M++2],
257 (0.03) [M+], 224 (0.22), 222 (2), 187 (15), 162 (38),
161 (100), 144 (16), 141 (18), 130 (23), 117 (18), 115
(59), 105 (20), 91 (31), 82 (17), 77 (20). HRMS (ESI): m/z
1
(250 MHz, CDCl3): d¼0.97 (t, J¼7.3 Hz, 3H, CH2CH3),
1.52 (sextet, J¼7.3 Hz, 2H, CH2CH3), 2.29 (3H, s,
CH3CCl2), 2.67–2.77 (m, 1H, (H)CHCH2CH3), 2.93–3.07
(m, 1H, (H)CHCH2CH3), 3.91 (s, 1H, CHNH), 7.24–7.33
(m, 3H, CHarom.meta+para), 7.42–7.51 (m, 2H, CHarom.ortho).
13C NMR (62.90 MHz, CDCl3): d¼11.7 (CH2CH3), 23.0
(CH2CH3), 34.2 (CH3CCl2), 50.1 (NHCH2), 64.2 (CCl2CH),
85.8 (C^CPh), 86.3 (C^CPh), 91.3 (CCl2), 122.5
(Carom.quat.), 128.3 (HCarom.meta), 128.5 (HCarom.para), 131.8
(HCarom.ortho). MS (EI, 70 eV): m/z (%)¼274 (0.01)
[M+5]+, 272 (0.07) [M+3]+, 270 (0.13) [M+H+], 177 (11),
176 (10), 172 (100), 141 (26), 139 (19), 130 (57), 129
(16), 116 (31), 115 (18), 113 (11), 103 (23), 102 (22), 97
(11), 77 (14), 63 (15). HRMS (ESI): m/z calcd for

S. Stas, K. A. Tehrani / Tetrahedron 63 (2007) 8921–8931
8929
calcd for C13H17NCl2+H: 258.0816; found: 258.0766. IR
(NaCl): 3323 (NH), 1494, 1448 (C]C) cmꢁ1
(CCl2CH), 59.9 (CH2OMe), 63.8 (OMe), 81.6 and 83.5
(C^C), 91.1 (CCl2). MS (EI, 70 eV): m/z (%)¼242 (0.4)
[M+5]+, 240 (2.7) [M+3]+, 238 (4) [M++1], 210 (16), 208
(22), 202 (20), 140 (100), 111 (32), 110 (32), 109 (34),
108 (61), 97 (38), 96 (37), 94 (35), 93 (39), 82 (38), 81
(39), 80 (40), 79 (42), 77 (46), 71 (53), 68 (36), 65 (39),
55 (32), 53 (36), 51 (38). HRMS (ESI): m/z calcd for
C10H18NCl2O+H: 238.0765; found: 238.0758. IR (ATR):
.
4.5.11. N-(4,4-Dichloro-1-(3-methoxyphenyl)pent-1-yne-
3-yl)propylamine (5hd). Yield: 132 mg (88%), yellow oil.
1H NMR (250 MHz, CDCl3): d¼0.97 (t, J¼7.4 Hz, 3H,
NHCH2CH2CH3), 1.49–1.67 (m, 2H, NHCH2CH2CH3),
2.28 (s, 3H, CH3CCl2), 2.66–2.76 and 2.92–3.02 (2ꢂm,
2H, NHCH2CH2CH3), 3.79 (s, 3H, OMe), 3.90 (s, 1H,
CCl2CH), 6.87 (ddd, J¼8.3, 2.6, 1.0 Hz, 1H, CHarom.
Carom.quat.OMe), 6.98 (dd, J¼1.9, 1.9 Hz, 1H, Carom.quat.
CHarom.Carom.quat.), 7.06 (ddd, J¼7.6, 1.2, 1.2 Hz, 1H,
C^CCarom.quat.CHarom), 7.22 (dd, J¼7.9, 7.9 Hz, 1H,
Carom.quat.CHarom.CHarom.CHarom.Carom.quat.). 13C NMR
(62.90 MHz, CDCl3): d¼11.7 (NHCH2CH2CH3), 23.0
(NHCH2CH2CH3), 34.2 (CH3CCl2), 50.2 (NHCH2), 55.3
(OMe), 64.2 (CCl2CH), 85.8 (C^CCarom.quat.), 86.2
(C^CCarom.quat.), 91.3 (CCl2), 115.0 (Carom.quat.CHarom.
Carom.quat.), 116.7 (MeOCarom.quat.CHarom.), 123.5 (C^
CCarom.quat.), 124.3 (C^CCarom.quat.CHarom.), 129.4 (MeO-
Carom.quat.CHarom.CHarom.), 159.3 (Carom.quat.OMe). MS (EI,
70 eV): m/z (%)¼303 (0.2) [M+4]+, 301 (0.5) [M+2]+, 299
(0.3) [M+], 206 (27), 203 (100), 171 (22), 161 (20), 160
(43), 159 (21), 158 (22), 145 (30), 133 (22), 128 (32), 127
(27), 117 (25), 115 (32), 102 (29), 101 (29), 89 (22).
HRMS (ESI): m/z calcd for C15H20NOCl2+H: 300.0922;
found: 300.0856. IR (ATR): 3294 (NH), 1597, 1574, 1488,
3343 (NH) cmꢁ1
.
4.5.14. N-(4,4-Dichloro-1-phenylpent-1-ene-3-yl)-N-(di-
fluoroboryl)ethylamine (8). Because of the impurities pres-
ent in this labile reaction mixture only following signals
1
could be distinguished in the spectra. H NMR (250 MHz,
CDCl3): d¼1.31 (t, J¼7.2 Hz, 3H, CH2CH3), 2.20 (s, 3H,
CH3CCl2), 2.95 and 3.19 (2ꢂdq, J¼12.2, 7.2 Hz, 2H,
CH2CH3), 3.87 (d, J¼9.1 Hz, 1H, CHNH), 6.20 (dd,
J¼15.8, 9.1 Hz, 1H, CH]CHPh), 6.76 (d, J¼15.8 Hz, 1H,
CH]CHPh), 7.24–7.60 (m, 5H, Ph). 13C NMR
(62.90 MHz, CDCl3, assignment by HMQC): d¼13.2
(CH2CH3), 34.7 (CH3CCl2), 42.4 (CH2CH3), 72.6 (CHNH),
90.2 (CCl2), 121.7 (CH]CHPh), 127.0 (HCarom.meta),
128.6 (HCarom.para), 128.8 (HCarom.ortho), 138.6 (CH]
CHPh). Carom.quat. could not be unambiguously assigned
because of interfering signals. 11B NMR (160.5 MHz,
CDCl3, BF3$OEt2 external standard): d¼0.7 (s). 19F NMR
(235.3 MHz, CDCl3): d¼ꢁ131.9 (s).
1480, 1463, 1426 (C]C) cmꢁ1
.
4.5.15. N-(4,4-Dichloro-1-(4-methylphenyl)pent-1-ene-3-
yl)ethylamine (5bf). Yield: 63 mg (46%, without HFIP),
yellow oil. 1H NMR (250 MHz, CDCl3): d¼1.13 (t,
J¼7.1 Hz, 3H, CH2CH3), 2.17 (s, 3H, CH3CCl2), 2.34 (s,
3H, Carom.quat.–CH3), 2.59 and 2.80 (2ꢂdq, J¼11.5,
7.2 Hz, 2H, CH2CH3), 3.44 (d, J¼8.6 Hz, 1H, CHNH),
6.06 (dd, J¼15.9, 8.6 Hz, 1H, CH]CHC6H4), 6.54 (d,
J¼15.9 Hz, 1H, CH]CHC6H4), 7.14 and 7.32 (2ꢂd,
J¼8.1 Hz, 4H, C6H4). 13C NMR (62.90 MHz, CDCl3):
d¼15.2 (CH2CH3), 21.2 (Carom.quat.CH3), 34.9 (CH3CCl2),
41.8 (CH2CH3), 72.9 (CHNH), 93.1 (CCl2), 125.4
(CH]CHC6H4), 126.5 and 129.3 (HCarom.ortho+meta),
133.5 (Carom.quat.CH3), 134.8 (CH]CHC6H4), 137.9
(CH]CHCarom.quat.). MS (EI, 70 eV): m/z (%)¼275 (0.02)
[M+4]+, 273 (0.03) [M+2]+, 271 (0.05) [M+], 238 (0.2),
236 (1), 200 (16), 175 (100), 157 (11), 156 (11), 144 (17),
142 (16), 141 (18), 130 (12), 129 (24), 128 (20), 119 (37),
115 (28), 105 (13), 91 (18), 82 (26). HRMS (ESI): m/z calcd
for C14H19NCl2+H: 272.0973; found: 272.0980. IR (ATR):
4.5.12. N-(4,4-Dichloro-1-(4-ethylphenyl)pent-1-yne-3-
yl)propylamine (5id). Yield: 134 mg (90%), yellow oil.
1H NMR (250 MHz, CDCl3): d¼0.96 (t, J¼7.4 Hz, 3H,
NHCH2CH2CH3), 1.21 (t, J¼7.6 Hz, 3H, CH2CH3), 1.49–
1.65 (m, 2H, NHCH2CH2CH3), 2.28 (s, 3H, CH3CCl2),
2.63 (q, J¼7.6 Hz, 2H, CH2CH3), 2.66–2.76 and 2.92–3.02
(2ꢂm, 2H, NHCH2CH2CH3), 3.90 (s, 1H, CCl2CH), 7.13
(d, J¼8.2 Hz, 2H, CH3CH2Carom.quat.(CHarom.)2), 7.38 (d,
J¼8.2 Hz, 2H, C^CCarom.quat.(CHarom.)2). 13C NMR
(62.90 MHz, CDCl3): d¼11.7 (NHCH2CH2CH3), 15.4
(CH2CH3), 23.0 (NHCH2CH2CH3), 28.8 (CH2CH3), 34.2
(CH3CCl2), 50.2 (NHCH2), 64.3 (CCl2CH), 85.6 (C^
CCarom.quat.), 86.0 (C^CCarom.quat.), 91.4 (CCl2), 119.7
(C^CCarom.quat.), 127.9 (CH3CH2Carom.quat.(Carom.)2), 131.8
(C^CCarom.quat.(Carom.)2), 145.0 (Carom.quat.Et). MS (EI,
70 eV): m/z (%)¼301 (0.07) [M+4]+, 299 (0.15) [M+2]+,
297 (0.13) [M+], 239 (22), 201 (100), 189 (30), 159 (23),
158 (61), 156 (28), 154 (26), 153 (29), 152 (29), 143 (33),
142 (28), 141 (31), 139 (29), 131 (27), 129 (25), 128 (31),
127 (29), 116 (22), 115 (48), 103 (28), 97 (20), 93 (25), 91
(25), 77 (27), 63 (22). HRMS (ESI): m/z calcd for
C16H22NCl2+H: 298.1129; found: 298.1105. IR (ATR):
3317 (NH); 2360, 2335 (C^C); 1509 and 1457 (C]C)
3322 (NH), 1513, 1443 (C]C), 1377 (HC]CH) cmꢁ1
.
4.5.16. N-(4,4-Dichloro-1-(4-chlorophenyl)pent-1-ene-3-
yl)ethylamine (5cf). Yield: 24 mg (16%, without HFIP),
yellow oil. 1H NMR (250 MHz, CDCl3): d¼1.13 (t,
J¼7.1 Hz, 3H, CH2CH3), 2.18 (s, 3H, CH3CCl2), 2.59 and
2.79 (2ꢂdq, J¼11.6, 7.1 Hz, 2H, CH2CH3), 3.44 (d,
J¼8.5 Hz, 1H, CHNH), 6.10 (dd, J¼15.9, 8.5 Hz, 1H,
CH]CHC6H4), 6.53 (d, J¼15.9 Hz, 1H, CH]CHC6H4),
7.26–7.37 (m, 4H, C6H4). 13C NMR (62.90 MHz, CDCl3):
d¼15.2 (CH2CH3), 34.8 (CH3CCl2), 41.9 (CH2CH3), 72.7
(CHNH), 92.8 (CCl2), 124.9 (CH]CCarom.quat.), 127.2
(CH]CHC6H4), 127.8 and 128.9 (HCarom.ortho+meta),
133.6 (CH]CHC6H4), 134.7 (Carom.quat.–Cl). MS (EI,
70 eV): m/z (%)¼297 (trace) [M+6]+, 295 (0.01) [M+4]+,
293 (0.01) [M+2]+, 291 (0.01) [M+], 258 (0.46), 256 (1),
cmꢁ1
.
4.5.13. N-(5,5-Dichloro-1-methoxy-2-hexyne-4-yl)pro-
pylamine (5jd). Yield: 53 mg (44%), yellow oil. H NMR
1
(250 MHz, CDCl3): d¼0.95 (t, J¼7.4 Hz, 3H,
NHCH2CH2CH3), 1.46–1.62 (m, 2H, NHCH2CH2CH3),
2.23 (s, 3H, CH3CCl2), 2.59–2.69 and 2.86–2.96 (2ꢂm,
2H, NHCH2), 3.40 (s, 3H, OMe), 3.74 (t, J¼1.7 Hz, 1H,
CCl2CH), 4.18 (d, J¼1.7 Hz, 2H, CH2OMe). 13C NMR
(62.90 MHz, CDCl3): d¼11.7 (NHCH2CH2CH3), 23.0
(NHCH2CH2CH3), 34.1 (CH3CCl2), 50.1 (NHCH2), 57.6

8930
S. Stas, K. A. Tehrani / Tetrahedron 63 (2007) 8921–8931
220 (10), 196 (64), 194 (100), 164 (10), 149 (15), 141 (21),
139 (21), 130 (11), 125 (11), 115 (20), 82 (13). HRMS: m/z
calcd for C13H16NCl3+H: 292.0427; found: 292.0320. IR
(ATR): 3306 (NH), 1490, 1444 (C]C), 1378 (HC]CH)
3H, CCl2CH2CH3), 1.21 (t, J¼7.2 Hz, 3H, NHCH2CH3),
1.83 (s, 1H, NH), 2.34 (q, J¼7.2 Hz, 2H, NHCH2), 2.58
and 2.81 (2ꢂqd, J¼11.4, 7.1 Hz, 2H, CH2CCl2), 3.48 (d,
J¼8.6 Hz, 1H, CHNH), 6.15 (dd, J¼15.9, 8.6 Hz, 1H,
CH]CHPh), 6.55 (d, J¼15.9 Hz, 1H, CH]CHPh); 7.19–
7.50 (m, 5H, Ph). 13C NMR (62.90 MHz, CDCl3): d¼9.3
(CH3CH2CCl2), 15.2 (NHCH2CH3), 38.5 (CH3CH2CCl2),
41.6 (NHCH2CH3), 71.3 (CHNH), 99.0 (CCl2), 126.4
(CH]CHPh), 128.0 (HCarom.para), 126.6 and 128.7
(HCarom.ortho+meta), 134.5 (CH]CHPh), 136.3 (Carom.quat.).
MS (EI, 70 eV): m/z (%)¼275 (0.01) [M+4]+, 273 (0.03)
[M+2]+, 271 (0.02) [M+], 200 (7), 162 (23), 160 (100), 141
(7), 130 (10), 129 (8), 128 (11), 127 (7), 117 (9), 115 (34),
105 (15), 91 (17), 82(9), 77 (14), 75 (8). HRMS (ESI): m/zcalcd
for C14H19NCl2+H: 272.0973; found: 272.1038. IR (ATR):
cmꢁ1
.
4.5.17. (Z)-N-(5,5-Dichloro-2-hexene-4-yl)ethylamine
(5ef). Yield: 23 mg (17%, without HFIP, 0.7 mmol), yellow
oil. Rf¼0.22 (Et2O/pentane, 1:9). 1H NMR (250 MHz,
CDCl3): d¼1.12 (t, J¼7.1 Hz, 3H, CH2CH3), 1.73 (dd,
J¼6.8, 1.7 Hz, 3H, CH]CHCH3), 2.15 (s, 3H, CH3CCl2),
2.56 and 2.75 (2ꢂdq, J¼11.4, 7.2 Hz, 2H, CH2CH3), 3.72
(dd, J¼9.5, 0.7 Hz, 1H, CHNH), 5.35 (ddq, J¼11.1, 9.5,
1.7 Hz, 1H, CH]CHCH3), 5.85 (dq, J¼11.1, 6.8 Hz,
1H, CH]CHCH3). 13C NMR (62.90 MHz, CDCl3): d¼
13.9 (CH2CH3), 15.3 (CH2CH3), 34.4 (CH]CHCH3),
41.7 (CH3CCl2), 65.7 (CHNH), 93.7 (CCl2), 128.1
(CH]CHCH3), 129.7 (CH]CHCH3). MS (EI, 70 eV):
m/z (%)¼200 (0.01) [M+5]+, 198 (0.16) [M+3]+, 196 (0.26)
[M+H+], 162 (1), 160 (4), 125 (2), 124 (16), 99 (28), 98
(100), 96 (18), 82 (13), 81 (21), 79 (31), 77 (19), 70 (37),
69 (18), 68 (24), 61 (11), 56 (26), 55 (15), 53 (22). HRMS
(ESI): (m/z) calcd for C8H15N37Cl35Cl: 198.0630; found:
3321 (NH), 1494, 1449 (C]C), 1379 (HC]CH) cmꢁ1
.
4.5.21. N-(4,4-Dichloro-1-phenylhex-1-ene-3-yl)allyl-
amine (11ae). Yield: 71 mg (50%, under reflux), yellow
oil. 1H NMR (250 MHz, CDCl3): d¼1.21 (t, J¼7.2 Hz,
3H, CH3), 1.66 (s, 1H, NH), 2.35 (q, J¼7.2 Hz, 2H,
CH2CCl2), 3.20 (dd, J¼14.1, 6.9 Hz, 1H, (H)CHCH]CH2),
3.43 (dd, J¼14.1, 5.0 Hz, 1H, (H)CHCH]CH2), 3.53 (d,
J¼8.7 Hz, 1H, CHNH), 5.11–5.25 (m, 2H, CH2CH]CH2),
5.81–5.97 (m, 1H, CH2CH]CH2), 6.14 (dd, J¼15.9,
8.7 Hz, 1H, CH]CHPh), 6.54 (d, J¼15.9 Hz, 1H,
CH]CHPh), 7.25–7.45 (m, 5H, Ph). 13C NMR
(62.90 MHz, CDCl3): d¼9.3 (CH3), 38.5 (CH3CH2), 49.5
(CH2CH]CH2), 70.1 (CHNH), 99.0 (CCl2), 116.6
(CH2CH]CH2), 125.9 (CH]CHPh), 128.0 (HCarom.para),
126.6 and 128.7 (HCarom.ortho+meta), 134.9 (CH]CHPh),
136.3 (Carom.quat.), 136.6 (CH2CH]CH2). MS (EI, 70 eV):
m/z (%)¼287 (0.03) [M+4]+, 285 (0.06) [M+2]+, 283
(0.04) [M+], 212 (12), 172 (100), 170 (17), 157 (13), 156
(12), 144 (12), 141 (19), 131 (29), 130 (29), 129 (29),
127 (21), 118 (24), 117 (16), 115 (52), 105 (12), 103
(16), 102 (15), 94 (14), 91 (51), 77 (38), 75 (20), 65
(12), 54 (12), 51 (18). HRMS (ESI): (m/z) calcd for
C15H19N37Cl35Cl: 286.0943; found: 286.0989. IR (ATR):
3332 (NH), 1494, 1448 (C]C), 1335, 1292 (HC]CH
198.0712. IR (ATR): 3335 (NH), 1445 (HC]CH) cmꢁ1
.
4.5.18. N-(4,4-Dichloro-1-phenylpent-1-yne-3-yl)ethyl-
amine (5gf). Yield: 102 mg (80%), yellow oil. H NMR
1
(250 MHz, CDCl3): d¼1.19 (t, J¼7.1 Hz, 3H, CH2CH3),
2.29 (s, 3H, CH3CCl2), 2.85 and 3.02 (2ꢂdq, J¼11.4,
7.1 Hz, 2H, CH2CH3), 3.93 (s, 1H, CHNH), 7.23–7.33 (m,
3H, CHarom.meta+para), 7.45–7.48 (m, 2H, CHarom.ortho). 13C
NMR (62.90 MHz, CDCl3, assignment by HMQC,
HMBC, and COSY): d¼15.5 (CH2CH3), 34.7 (CH3CCl2),
43.0 (CH2CH3), 64.5 (CHNH), 86.3 and 86.6 (C^C),
91.6 (CCl2), 122.9 (Carom.quat.), 128.7 (HCarom.meta), 128.9
(HCarom.para), 132.2 (HCarom.ortho). MS (EI, 70 eV): m/z
(%)¼260 (trace) [M+5]+, 258 (0.06) [M+3]+, 256 (0.21)
[M+H+], 175 (10), 158 (100), 141 (29), 139 (25), 130 (43),
128 (54), 115 (59), 113 (17), 103 (69), 99 (13), 97 (15), 91
(12), 89 (10), 77 (40), 75 (11), 74 (13), 63 (26), 61 (13),
56 (13), 51 (19). HRMS (ESI): m/z calcd for C13H15NCl2+H:
256.0660; found: 256.0538. IR (ATR): 1374, 1291 (C]C
and CH]CH2) cmꢁ1
.
aromate) cmꢁ1
.
4.5.22. N-(4,4-Dichloro-1-phenyl-5-methylhex-1-ene-3-
yl)allylamine (12ae). Yield: 41 mg (28%, pressure tube),
1
4.5.19. N-(4,4-Dichloro-1-phenylpent-1-ene-3-yl)methyl-
amine (5ag). Yield: 84 mg (69%), yellow oil. H NMR
yellow oil. H NMR (250 MHz, CDCl3): d¼1.16 and 1.37
1
(2ꢂd, J¼6.4 Hz, 2ꢂ3H, CH(CH3)2), 1.64 (s, 1H, NH),
2.66 (septet, J¼6.4 Hz, 1H, CH(CH3)2), 3.18 (dd, J¼13.9,
7.0 Hz, 1H, (H)CHCH]CH2), 3.42 (dd, J¼13.9, 5.1 Hz,
1H, (H)CHCH]CH2), 3.59 (d, J¼8.7 Hz, 1H, CHNH),
5.11–5.24 (m, 2H, CH2CH]CH2), 5.77–5.97 (m, 1H,
CH2CH]CH2), 6.16 (dd, J¼15.9, 8.7 Hz, 1H, CH]CHPh),
6.51 (d, J¼15.9 Hz, 1H, CH]CHPh), 7.24–7.45 (m, 5H,
Ph). 13C NMR (62.90 MHz, CDCl3): d¼18.1 (CH(CH3)2),
39.9 (CH(CH3)2), 49.3 (CH2CH]CH2), 68.1 (CHNH),
104.0 (CCl2), 116.7 (CH2CH]CH2), 125.8 (CH]CHPh),
128.0 (HCarom.para), 126.6 and 128.6 (HCarom.ortho+meta),
(250 MHz, CDCl3): d¼2.26 (s, 3H, NHCH3), 2.47 (s, 3H,
s, CH3CCl2), 3.34 (d, J¼8.6 Hz, 1H, CHNH), 6.09 (dd,
J¼15.9, 8.6 Hz, 1H, CH]CHPh), 6.61 (d, J¼15.9 Hz, 1H,
CH]CHPh), 7.22–7.47 (m, 5H, Ph). 13C NMR
(62.90 MHz, CDCl3): d¼34.4 (NHCH3), 34.9 (CH3CCl2),
75.0 (CHNH), 92.7 (CCl2), 125.6 (CH]CHPh), 128.1
(HCarom.para), 126.6 and 128.7 (HCarom.ortho+meta), 135.7
(CH]CHPh), 136.1 (Carom.quat.). MS (EI, 70 eV): m/z
(%)¼247 (0.02) [M+4]+, 245 (0.03) [M+2]+, 243 (0.02)
[M+], 172 (16), 148 (32), 146 (100), 145 (14), 141 (12),
131 (11), 130 (12), 128 (19), 117 (12), 115 (58), 91 (57),
77 (16), 68 (15), 51 (12). IR (ATR): 1494, 1448 (aromate),
134.5
(CH]CHPh),
136.3
(Carom.quat.),
136.6
(CH2CH]CH2). MS (EI, 70 eV): m/z (%)¼301 (trace)
[M+4]+, 299 (trace) [M+2]+, 297 (trace) [M+], 172 (100),
144 (14), 131 (21), 130 (23), 129 (20), 127 (19), 118 (19),
117 (15), 115 (53), 106 (11), 104 (12), 91 (51), 89 (12), 77
(27), 52 (20). HRMS (ESI): m/z calcd for C16H21NCl2+H:
298.1129; found: 298.0971. IR (ATR): 3318 (NH), 1495,
1376 (HC]CH) cmꢁ1
.
4.5.20. N-(4,4-Dichloro-1-phenylhex-1-ene-3-yl)ethyl-
amine (11af). Yield: 45 mg (33%, under reflux), yellow
oil. 1H NMR (250 MHz, CDCl3): d¼1.13 (t, J¼7.1 Hz,

S. Stas, K. A. Tehrani / Tetrahedron 63 (2007) 8921–8931
8931
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