Synthesis of 1-stannylated and 1-iodinated 1-chloroalkenes as versatile synthetic intermediates

Article abstract of DOI:10.1055/s-0030-1259057

An efficient and convenient synthesis of 1-stannylated and iodinated 1-chloroalkenes is described based on MoBI₃-catalyzed hydrostannations of 1-chloroalkynes, followed by a tin-iodine exchange. The 1-chloro-1-iodoalkenes are suitable substrates for further modification, for example, via cross-coupling reactions.

Full text of DOI:10.1055/s-0030-1259057

LETTER
3073
Synthesis of 1-Stannylated and 1-Iodinated 1-Chloroalkenes as Versatile
Synthetic Intermediates
S
ynthesis of 1-Stannylated a
m
nd 1-Iodinated 1-Ch
e
loroalkene
n
s
dra Pratap, Uli Kazmaier*
Institut für Organische Chemie, Universität des Saarlandes, 66123 Saarbrücken, Germany
Fax +49(681)3022409; E-mail: u.kazmaier@mx.uni-saarland.de
Received 7 October 2010
example, chloroiodoalkenes can be used for the stereo-
selective synthesis of highly functionalized alkenes.14 Un-
fortunately, procedures for the synthesis of these
interesting building blocks are rather limited. They can be
Abstract: An efficient and convenient synthesis of 1-stannylated
and iodinated 1-chloroalkenes is described based on MoBI3-cata-
lyzed hydrostannations of 1-chloroalkynes, followed by a tin–
iodine exchange. The 1-chloro-1-iodoalkenes are suitable sub-
strates for further modification, for example, via cross-coupling re- obtained by addition of hydrogen chloride to iodopropiol-
actions.
ic acid, providing the two stereoisomers in almost equal
amounts.15 In principle, hydrogen iodide can also be add-
Key words: chloroalkynes, cross-coupling, hydrostannation, mo-
lybdenum, vinyl halides
ed towards chloroalkynes, but these reactions usually end
up with diaddition products.16 Although the halogen ex-
change between dichlororvinylethyl sulfone and sodium
iodide also yields the desired product,17 in general vinyl-
chlorides are unsatisfactory substrates because of their re-
luctance towards exchange.18 Barluenga et al. described
the formation of chloroiodoalkenes by reaction of 1-chlo-
roalkynes with bis(pyridine)iodine(I) tetrafluoroborate.19
For synthetic chemists vinylstannanes are very attractive
synthetic building blocks, especially because they are eas-
ily accessible, for example, via hydrostannations of
alkynes. Generally, these hydrostannations can be per-
formed under radical or transition-metal-catalyzed condi-
tions.1 Most of these methods are suffering from
difficulties in controlling the regioselectivity of the tin hy-
dride addition to unsymmetrical alkynes, though transi-
tion-metal-catalyzed reactions provide clean cis addition,
based on the reaction mechanism.2 Hydrometallations of
terminal alkynes generally give rise to the terminal (E)-
vinylstannanes, also accessible via stannylcupration.3
Yamamoto et al. reported the synthesis of the correspond-
ing Z-isomers in the presence of Lewis acids,4 and
Williams et al. described a Z-selective hydrotelluration–
transmetallation approach.5 In addition, Hale et al.6 as
well as the group of Miura and Hosomi7 reported the re-
gioselective, radical hydrostannation of propargyl alcohol
derivatives. Our group has developed a new molybde-
num-based catalyst Mo(CO)3(CNt-Bu)3 (MoBI3), which
is especially suitable for highly regio- and stereoselective
hydrostannations of functionalized alkynes.8 Best results
are obtained with terminal, electron-poor alkynes, to
which the tin moiety is transferred towards the sterically
more hindered position, close to the electron-withdrawing
group.9 For example, propargyl acetate or carbonates give
excellent yields of the stannylated derivatives, which are
ideal substrates for further modifications, such as allylic
alkylations and Stille couplings (Scheme 1).10
Herein, we describe our investigations of Mo-catalyzed
regio- and stereoselective hydrostannations of 1-chloro-
alkynes 1, and the conversion of the chlorinated vinylstan-
nanes
2
obtained into the corresponding 1,1-
chloroiodoalkenes 4 (Table 1). The required chloro-
alkynes can easily be obtained from terminal alkynes via
deprotonation and halogenation with N-chlorosuccinim-
ide (NCS).20 Although in these substrates the triple bond
is not terminal, we hoped that the electron-withdrawing
effect of the halogen might cause a regioselective tin hy-
dride addition. And indeed, in the presence of 3 mol%
Mo(CO)3(CNt-Bu)3 (MoBl3) 1-chloropentyne (1a) was
hydrostannated regio- and stereoselectively towards chlo-
rostannane 2a. The crude product was carefully investi-
gated by NMR, and only one set of signals was observed
1
in the H, 13C, and 119Sn spectra. By far the best results
were obtained in the presence of a slight excess of
Bu3SnH (1.5 equiv)21 and with THF as solvent at 60 °C
(Table 1, entry 1). Hydroquinone was added to suppress
competitive radical hydrostannations. Interestingly, a CO
atmosphere had no influence on the outcome of the reac-
tion, as observed previously with terminal alkynes.22
Bu3SnH
Mo(CO)3(CNt-Bu)3
Vinyl iodides are also interesting synthetic precursors due
to their versatility in organic synthesis11 and photochem-
istry.12 The iodide can be transformed selectively in the
presence of other, less reactive, leaving groups.11a,13 For
Bu3Sn
89%
95% rs
OCOOEt
OCOOEt
THF, CO, 50 °C, 2 h
allylic alkylations
Stille couplings
SYNLETT 2010, No. 20, pp 3073–3077
Advanced online publication: 19.11.2010
x
x
.x
x
.2
0
1
0
Scheme 1 Molybdenum-catalyzed hydrostannations
DOI: 10.1055/s-0030-1259057; Art ID: G28310ST
© Georg Thieme Verlag Stuttgart · New York

3074
R. Pratap, U. Kazmaier
LETTER
Therefore, we investigated the hydrostannation of several
other chloroalkynes (entries 2–5) under these optimized
reaction conditions.23 While all alkyl-substituted alkynes
gave comparable results, the corresponding phenyl deri-
vate 1e provided a mixture of the two regioisomeric prod-
ucts 2e and 3e in a 7:3 ratio. In this case, the reaction does
not go to completion, even though the amount of catalyst
was increased to 5 mol%. But the different reaction be-
havior of the arylalkynes is not surprising and was previ-
ously also observed by various other investigators.2
R
n
R
Product
Yield (%)
4
5
5
Ph
92
90
85
6c
6d
6e
Ph
SiMe
Cl
n
6
Pd(PPh3)4 (5 mol%)
CuI (10 mol%)
piperidine (2 equiv)
benzene, 60 °C, 4 h
R
(2 equiv)
I
Table 1 Synthesis of Chlorinated Vinylstannanes and Vinyliodides
SnBu3 (1.2 equiv)
SnBu3
PdCl2(PPh3)2 (5 mol%)
DMF, 30 min, r.t.
Bu3Sn
Cl
Cl
Bu3SnH (1.5 equiv)
n
5
R
Cl
+
4
7d
67%
MoBI3 (3 mol%)
hydroquinone
THF, 60 °C, 24 h
R
Cl
R
Cl
1
2
3
Pd(PPh3)4 (5 mol%)
Na2CO3 (2 equiv)
DME, Δ, 24 h
PhB(OH)2
(1.2 equiv)
I2, CH2Cl2, 1 h
MoBI3: Mo(CO)3(CNt-Bu)3
I
I
+
R
Cl
R
Cl
4
5
+
Entry
Substrate
R
Product Yield
(%)
Product Yield
(%)
Cl
5
5
8d
45%
9d
16%
1
2
3
4
5
1a
1b
1c
1d
1e
n-Pr
2a
69
4a
77
Scheme 2 Cross-coupling reactions of chloroiodoalkenes
n-Bu
n-Pen
n-Hex
Ph
2b
75
4b
86
2c
76
4c
79
withdrawing substituents on both sides. Therefore, we ex-
pected, that the substrates should react under the usual
reaction conditions (what is not the case with alkylsubsti-
tuted propargyl alcohol derivatives), but that the regiose-
lectivity should be moderate based on the opposite
directing effects of the substituents. When we run the ex-
periments we expected to obtain two products as before,
but were surprised to find up to six compounds in the
crude reaction mixture (determined by NMR). In the case
of the THP-protected alkyne 1f the expected regioisomer-
ic products (E)-2f and (E)-3f were only the minor stereo-
isomers, while the Z-isomers (Z)-2f and (Z)-3f were the
major components in the product mixture. In addition, the
dehalogenated product 10f and the hydrostannation prod-
uct 11f thereof were obtained (entry 1).
2d
78
4d
85
2e/3e
42/19
4e/5e
48/21
The stannylated chlorostannanes obtained were subjected
to a subsequent tin–iodide exchange.24 This clean reaction
provided the requested mixed dihalogenated alkenes in
good yield and with retention of the olefin geometry. Be-
cause the stannylated phenylsubstituted alkenes were dif-
ficult to separate by chromatography, the regioisomeric
mixture was subjected to the halogen exchange. There-
fore, a mixture of the alkenes 4e and 5e was obtained.
With these chloroiodoalkenes in hand we carried out a
series of cross coupling reactions (Scheme 2). The
Sonogashira coupling of 4 with various alkynes yielded
enynes 6 in excellent yield and with complete retention of
olefin geometry25 and the Stille coupling of 4d with vinyl
tributyltin at room temperature provided the chlorinated
diene 7d in 67% yields.26 Interestingly, the Suzuki cou-
pling with phenylboronic acid gave rise to a mixture of
mono- and diarylated products.27
In the first instance we assumed that 10f might be formed
via reduction of the chloroalkyne 1f under the reaction
conditions, a process which might also explain the ‘less
than perfect yield’ with the other alkynes 1a–e, because
the nonchlorinated alkynes are volatile and do not under-
go hydrostannation. But during workup we made an inter-
esting observation: After column chromatography (E)-3f
had disappeared completely, while the product ratio of the
other components was nearly unchanged (entry 2). Only
the amount of 10f was significantly increased. Obviously,
this E-isomer is not very stable and undergoes elimination
towards 10 easily, at least in the presence of silica gel. To
prove this hypothesis, we added silica gel to the crude re-
action mixture and analyzed this after stirring for 24 hours
(entry 3). Again, the E-isomer was completely gone, and
To evaluate the scope and limitations of this protocol we
also investigated the hydrostannation of chlorinated prop-
argyl alcohol derivatives 1f and 1g (Table 2). Terminal
propargyl alcohols are excellent substrates for highly re-
gioselective hydrostannations, and the regioselectivity
correlates with the electron-withdrawing effect of the oxy
substituent. In our case, the alkynes have two electron-
Synlett 2010, No. 20, 3073–3077 © Thieme Stuttgart · New York

LETTER
Synthesis of 1-Stannylated and 1-Iodinated 1-Chloroalkenes
3075
Table 2 Hydrostannation of Chlorinated Propargylalcohol Derivatives
SnBu3
Cl
Cl
Bu3Sn
Bu3Sn
Cl
Bu3Sn
Bu3SnH (1.5 equiv)
Cl
+
+
+
Cl
+
+
SnBu3
MoBI3 (5 mol%)
hydroquinone
THF, 60 °C, 24 h
RO
OR
(E)-2f,g
OR
(Z)-2f,g
OR
(E)-3f,g
OR
(Z)-3f,g
OR
10f,g
OR
11f,g
1f,g
Entry
Substrate
R
Workup
Product ratio (%)
(E)-2
16
(Z)-2
(E)-3
(Z)-3
10
9
11
6
1
2
3
4
5
6
1f
THP
THP
THP
Me
crude product
after chromatography
49
46
49
35
45
44
9
11
13
14
–
1f
20
–
–
15
12
4
6
1f
stirring with SiO2 for 24 h
crude product
19
6
1g
1g
1g
35
17
–
9
Me
after chromatography
stirring with SiO2 for 24 h
47
–
1
7
Me
46
–
–
1
9
1857. (f) Baldwin, J. E.; Adlington, R. M.; Ramcharitar, S.
H. J. Chem. Soc., Chem. Commun. 1991, 940. (g) Davies,
A. G. In Comprehensive Organometallic Chemistry II, Vol.
2; Pergamon: Oxford, 1995, 217ff. (h) Davies, A. G.
Organotin Chemistry; VCH: Weinheim, 1997.
the product ratio was comparable to the result after flash
chromatography. As a second substrate we subjected the
corresponding methylether 1g towards the same protocol.
In this case, the elimination product 10g is volatile (bp
61 °C) and should disappear. Although traces of 10g
could be determined in the crude reaction mixture, after
SiO2 treatment the expected 1-chloro-1-stannylalkene 2g
was obtained as a 1:1 isomeric mixture, accompanied by
9% of the simple hydrostannation product 11g. Probably,
the instability of the 2-stannylated 1-chloralkenes 3 can
also explain the perfect regioselectivity observed in the
reactions of substrates 1a–d (Table 1).
(2) For reviews, see: (a) Smith, N. D.; Mancuso, J.; Lautens, M.
Chem. Rev. 2000, 100, 3257. (b) Trost, B. M.; Ball, Z. T.
Synthesis 2005, 853; and references cited therein.
(3) (a) Hibino, J.; Matsubara, S.; Morizawa, Y.; Oshima, K.
Tetrahedron Lett. 1984, 25, 2151. (b) Barbero, A.;
Cuadradro, P.; Fleming, I.; Gonzalez, A. M.; Pulido, F. J.
J. Chem. Soc., Chem. Commun. 1992, 351. (c) Reginato,
G.; Mordini, A.; Caracciolo, M. J. Org. Chem. 1997, 62,
6187.
(4) (a) Asao, N.; Liu, J. X.; Sudoh, T.; Yamamoto, Y. J. Chem.
Soc., Chem. Commun. 1995, 2405. (b) Asao, N.; Liu, J. X.;
Sudoh, T.; Yamamoto, Y. J. Org. Chem. 1996, 61, 4568.
(5) Mirzayans, P. M.; Pouwer, R. H.; Williams, C. M. Org. Lett.
2008, 10, 3861.
(6) (a) Dimopoulos, P.; Athlan, A.; Manaviazar, S.; George, J.;
Walters, M.; Lazarides, L.; Aliev, A. E.; Hale, K. J. Org.
Lett. 2005, 7, 5369. (b) Dimopoulos, P.; Athlan, A.;
Manaviazar, S.; Hale, K. J. Org. Lett. 2005, 7, 5373.
(c) Dimopoulos, P.; George, J.; Tocher, D. A.; Manaviazar,
S.; Hale, K. J. Org. Lett. 2005, 7, 5377.
In conclusion, we have shown that molybdenum-
catalyzed hydrostannations of 1-chloroalkynes give rise
to stannylated chloroalkenes, which undergo tin–iodide
exchange towards the corresponding chloroiodoalkenes,
suitable precursors for subsequent palladium-catalyzed
cross coupling reactions.
Best results were obtained with alkyl-substituted alkynes,
which form the E-configured 1-stannylated 1-chloro al-
kenes as a single regio- and stereoisomer. Further mecha-
nistic studies, as well as synthetic applications are
currently under investigation.
(7) Miura, K.; Wang, D.; Matsumoto, Y.; Hosomi, A. Org. Lett.
2005, 7, 503.
(8) (a) Kazmaier, U.; Schauß, D.; Pohlman, M. Org. Lett. 1999,
1, 1017. (b) Kazmaier, U.; Pohlman, M.; Schauß, D. Eur. J.
Org. Chem. 2000, 2761. (c) Kazmaier, U.; Schauß, D.;
Pohlman, M.; Raddatz, S. Synthesis 2000, 914. (d) Braune,
S.; Kazmaier, U. J. Organomet. Chem. 2002, 641, 26.
(9) (a) Braune, S.; Pohlman, M.; Kazmaier, U. J. Org. Chem.
2004, 69, 468. (b) Kazmaier, U.; Wesquet, A. Synlett 2005,
1271. (c) Wesquet, A. O.; Dörrenbächer, S.; Kazmaier, U.
Synlett 2006, 1105. (d) Kazmaier, U.; Dörrenbächer, S.;
Wesquet, A.; Lucas, S.; Kummeter, M. Synthesis 2007, 320.
(e) Jena, N.; Kazmaier, U. Eur. J. Org. Chem. 2008, 3852.
(10) (a) Kazmaier, U.; Schauß, D.; Raddatz, S.; Pohlman, M.
Chem. Eur. J. 2001, 7, 456. (b) Dörrenbächer, S.;
Kazmaier, U.; Ruf, S. Synlett 2006, 547. (c) Deska, J.;
Kazmaier, U. Angew. Chem. Int. Ed. 2007, 46, 4570; Angew.
Chem. 2007, 119, 4654. (d) Deska, J.; Kazmaier, U. Chem.
Eur. J. 2007, 13, 6204. (e) Bukovec, C.; Kazmaier, U. Org.
Lett. 2009, 11, 3518.
Acknowledgment
This work was supported by the Deutsche Forschungsgemeinschaft
and by the Fonds der Chemischen Industrie. Ramendra Pratap
thanks the Alexander von Humboldt Foundation for a postdoctoral
fellowship.
References and Notes
(1) (a) Leusink, A. J.; Budding, H. A.; Drenth, W. J.
Organomet. Chem. 1967, 9, 295. (b) Ichinose, Y.; Oda, H.;
Oshima, K.; Utimoto, K. Bull. Chem. Soc. Jpn. 1987, 60,
3468. (c) Nozaki, K.; Oshima, K.; Utimoto, K. J. Am. Chem.
Soc. 1987, 109, 2547. (d) Zhang, H. X.; Guibe, F.;
Balavoine, G. Tetrahedron Lett. 1988, 29, 619. (e) Zhang,
H. X.; Guibé, F.; Balavoine, G. J. Org. Chem. 1990, 55,
Synlett 2010, No. 20, 3073–3077 © Thieme Stuttgart · New York

3076
R. Pratap, U. Kazmaier
LETTER
(E)-Tributyl(1-chloro-3-methoxypropenyl)stannane
(11) See, for example: (a) Negishi, E. Organometallics in
Organic Synthesis; J. Wiley: New York, 1980, 30.
(b) Posner, G. H. An Introduction to Synthesis Using
Organocopper Reagents; R. E. Krieger: Malabor, 1988, 72.
(c) Hanack, M. Angew. Chem., Int. Ed Engl. 1978, 17, 333.
(d) Negishi, E.; Valente, L. F.; Kobayashi, M. J. Am. Chem.
Soc. 1980, 102, 3298. (e) Kropp, P. J. Acc. Chem. Res. 1984,
17, 131.
(12) Kropp, P. J.; McNeely, S. A.; Davis, R. D. J. Am. Chem. Soc.
1983, 105, 6907.
(13) (a) Negishi, E.; Okukado, N.; Lovich, L. F.; Luo, F. J. Org.
Chem. 1984, 49, 2629. (b) Tellier, F.; Sauvetre, R.;
Normant, J. Tetrahedron Lett. 1986, 27, 3147.
(14) Alami, M.; Crousse, B.; Linstrumelle, G. Tetrahedron Lett.
1995, 36, 3687.
(15) Andersson, K. Chem. Scr. 1972, 2, 117.
(16) Delavarenne, S. Y.; Viehe, H. G. In The Chemistry of
Acetylenes; Marcel Dekker: New York, 1969, Chap. 10, 699.
(17) Shainyan, B. A.; Mirskowa, A. N. Zh. Org. Khim. 1983, 19,
1146.
(18) Suzuki, H.; Aihara, M.; Yamamoto, H.; Tamamoto, Y.;
Ogawa, T. Synthesis 1988, 237.
[(E)-2g]
Colorless oil. 1H NMR (400 MHz, CDCl3): d = 0.92 (t,
J = 7.3 Hz, 9 H, CH3), 1.06–1.11 (m, 6 H, CH2), 1.31–1.40
(m, 6 H, CH2), 1.52–1.60 (m, 6 H, CH2), 3.38 (s, 3 H, OCH3),
4.23 (d, J = 5.3 Hz, JSn–H = 14.5 Hz, 2 H, CHCH2), 5.27 (t,
J = 5.3 Hz, JSn–H = 31.1 Hz, 1 H, CH) ppm. 13C NMR (100
MHz, CDCl3): d = 10.4, 13.6, 27.2, 28.7, 58.1, 69.4, 138.6,
142.2 ppm. 119Sn NMR (150 MHz, CDCl3): d = –28.3 ppm.
HRMS: m/z calcd for C12H24OClSn [M – C4H9]+: 339.0533;
found: 339.0525.
(Z)-Tributyl(1-chloro-3-methoxypropenyl)stannane
[(Z)-2g]
Colorless oil. 1H NMR (400 MHz, CDCl3): d = 0.93 (t,
J = 7.1 Hz, 9 H, CH3), 1.06–1.11 (m, 6 H, CH2), 1.31–1.40
(m, 6 H, CH2), 1.52–1.60 (m, 6 H, CH2), 3.34 (s, 3 H, OCH3),
3.87 (d, J = 6.5 Hz, JSn–H = 14.5 Hz, 2 H, CHCH2), 6.64 (t,
J = 6.5 Hz, JSn–H = 75.3 Hz, 1 H, CH) ppm. 13C NMR (100
MHz, CDCl3): d = 11.6 (JSn–C = 348.0 Hz), 13.6, 27.2
(JSn–C = 60.8 Hz), 28.7 (JSn–C = 19.8 Hz), 57.9, 71.6
(JSn–C = 14.7 Hz), 139.7, 142.1 ppm. 119Sn NMR (150 MHz,
CDCl3): d = –32.21 ppm. HRMS: m/z calcd for
(19) Barleunga, J.; Rodríguez, M. A.; Campos, P. J. Tetrahedron
C12H24OClSn [M – C4H9]+: 339.0533; found: 339.0525.
(E)-Tributyl(1-methoxymethylvinyl)stannane (11g)
Colorless oil. 1H NMR (400 MHz, CDCl3): d = 0.89–0.95
(m, 15 H, CH2 and CH3), 1.31–1.36 (m, 6 H, CH2), 1.48–
1.56 (m, 6 H, CH2), 3.32 (s, 3 H, OCH3), 4.05 (d, J = 1.5 Hz,
JSn–H = 34.6 Hz, 2 H, CH2), 5.28 (dt, J = 2.7, 1.7 Hz,
JSn–H = 62.2 Hz, 1 H, CH), 5.88 (dt, J = 2.7, 1.7 Hz,
JSn–H = 131.0 Hz, 1 H, CH) ppm. 13C NMR (100 MHz,
CDCl3): d = 9.5, 13.7, 27.3, 29.1, 57.7, 79.7, 124.6, 153.0
ppm. 119Sn NMR (150 MHz, CDCl3): d = –45.4 ppm.
HRMS: m/z calcd for C12H25OSn [M – C4H9]+ 305.0922;
found: 305.0920.
Lett. 1990, 31, 2751.
(20) Murray, R. E. Synth. Commun. 1980, 10, 345.
(21) The slight excess of Bu3SnH was used to allow complete
conversion, because during transition-metal-catalyzed
hydrostannations in general a certain amount of the tin
hydride decomposes towards Bu3SnSnBu3.
(22) (a) Wesquet, A. O.; Kazmaier, U. Adv. Synth. Catal. 2009,
1395. (b) Lin, H.; Kazmaier, U. Eur. J. Org. Chem. 2009,
1221.
(23) General Procedure for MoBI3-Catalyzed
Hydrostannations
In an oven-dried Schlenk tube the corresponding
chloroalkyne (1 mmol) and Mo(CO)3(CNt-Bu)3 (MoBI3,
12.9 mg, 30 mmol) were dissolved together with hydro-
quinone (10 mg, 91 mmol) in dry THF (2 mL) under argon.
The solution was heated to 60 °C for 10 min before Bu3SnH
(435 mg, 1.5 mmol) was added. The reaction mixture was
stirred for 16–24 h. After completion, the reaction mixture
was cooled to r.t., and the solvent was evaporated in vacuo.
The crude product was purified by flash chromatography on
silica gel (neutralized with Et3N) using pentane or hexane as
an eluent.
(24) Representative Procedure for the Synthesis of 1-Chloro-
1-iodoalkenes
A solution of iodine (280 mg, 1.1 mmol) in CH2Cl2 (8.0 mL)
was added dropwise (up to 1 h) to the solution of tributyl(1-
chlorohex-1-enyl)stannane (2b, 408 mg, 1 mmol) in CH2Cl2
(7.0 mL) at 0 °C. After addition of the iodine solution the
cooling bath was removed, and the reaction mixture was
stirred at r.t. for 1 h, before the reaction mixture was stirred
with sat. KF solution (15 mL) for 2 h. The organic layer was
separated, and the aqueous layer was extracted with CH2Cl2
(10 mL). The combined organic layers were dried over
Na2SO4. After evaporation of the solvent, the crude product
was purified by flash chromatography using hexane as
eluent to yield 1-chloro-1-iodo-1-hexene (4b) as colorless
oil.
Tributyl(1-chloro-1-pentenyl)stannane (2a)
Colorless oil. 1H NMR (400 MHz, CDCl3): d = 0.92 (t,
J = 7.0 Hz, 12 H, CH3), 1.01–1.05 (m, 6 H, CH2), 1.28–1.37
(m, 8 H, CH2), 1.52–1.58 (m, 6 H, CH2), 2.30 (dt, J = 6.9 Hz,
JSn–H = 14.2 Hz, 2 H, CHCH2), 5.79 (t, J = 6.9 Hz, JSn–H
32.4 Hz, 1 H, CH) ppm. 13C NMR (100 MHz, CDCl3):
d = 10.3 (JSn–C = 342.6 Hz), 13.6, 13.7, 21.8, 27.2 (JSn–C
60.2 Hz), 28.7 (JSn–C = 22.7 Hz), 30.8, 136.8, 142.0 ppm.
119Sn NMR (150 MHz, CDCl3): d = –31.9 ppm. HRMS:
m/z calcd for C13H26ClSn [M – C4H9]+: 337.0740; found:
337.0729.
=
1-Chloro-1-iodo-1-hexene (4b)
1H NMR (400 MHz, CDCl3): d = 0.93 (t, J = 7.8 Hz, 3 H,
CH3), 1.34–1.42 (m, 4 H, CH2), 2.18 (q, J = 7.5 Hz, 2 H,
CH2), 6.45 (t, J = 7.5 Hz, 1 H, CH) ppm. 13C NMR (100
MHz, CDCl3): d = 13.8, 22.1, 30.0, 31.4, 66.3, 144.4 ppm.
HRMS (CI): m/z calcd for C6H10ClI [M]+: 243.9516; found:
243.9556.
=
Tributyl(1-chloro-1-octenyl)stannane (2d)
(25) Representative Procedure for Sonogashira Couplings
In an oven-dried Schlenk tube CuI (17.0 mg, 10 mol%) was
added to a solution of Pd(PPh3)4 (44.0 mg, 5 mol%) in
benzene (2 mL) under Ar. To this mixture 1-chloro-1-iodo-
1-heptene (4c, 223 mg, 0.87 mmol) and piperidine (178 mL,
1.74 mmol) were added before it was warmed up to 60 °C.
Phenyl acetylene was added dropwise (over 1 h), and the
reaction mixture was heated at this temperature for addi-
tional 4 h. After the reaction was complete (TLC), the
mixture was cooled to r.t. and diluted with Et2O (20 mL).
The organic layer was washed with sat. NH4Cl solution and
Colorless oil. 1H NMR (400 MHz, CDCl3): d = 0.92 (t,
J = 7.2 Hz, 12 H, CH3), 1.01–1.05 (m, 6 H, CH2), 1.31–1.38
(m, 14 H, CH2), 1.50–1.56 (m, 6 H, CH2), 2.32 (dt, J = 6.9
Hz, JSn–H = 14.5 Hz, 2 H, CHCH2), 5.80 (t, J = 6.4 Hz,
JSn–H = 32.1 Hz, 1 H, CH) ppm. 13C NMR (100 MHz,
CDCl3): d = 10.3 (JSn–C = 341.8 Hz), 13.6, 14.1, 22.6, 27.2,
(JSn–C = 57.2 Hz), 28.6, 28.8, 28.9, 31.7, 136.6, 142.3 ppm.
119Sn NMR (150 MHz, CDCl3): d = –32.0 ppm. HRMS:
m/z calcd for C16H32ClSn [M – C4H9]+: 365.1053; found:
365.1033.
Synlett 2010, No. 20, 3073–3077 © Thieme Stuttgart · New York

LETTER
Synthesis of 1-Stannylated and 1-Iodinated 1-Chloroalkenes
3077
H2O (20 mL each). The organic layer was separated, dried
EtOH (0.2 mL) was added to a Schlenk tube containing a
solution of Pd(PPh3)4 (11.5 mg, 5 mol%) and 1-chloro-1-
iodo-1-octene (4d, 54.0 mg, 0.2 mmol) in DME (1.0 mL)
under argon. A solution of Na2CO3 (64 mg, 0.6 mmol) in
degassed H2O (0.5 mL) was added to the reaction mixture,
and the mixture was heated under reflux for 24 h. The
reaction mixture was then cooled to r.t., diluted with H2O (10
mL) and Et2O (10 mL). The layers were separated, and the
aqueous layer was extracted with Et2O (10 mL). The
combined organic layers were washed with H2O and dried
over anhyd Na2SO4, filtered, and concentrated under
reduced pressure. The crude product obtained was purified
by flash chromatography on silica gel using hexanes to yield
19.0 mg (45%) of monoarylated product 8d and 9.6 mg
(16%) of diarylated product 9d.
over Na2SO4 and evaporated to dryness. The crude product
obtained was purified by flash chromatography using
hexane as eluent.
(Z)-1-Phenyl-3-chloro-3-nonen-1-yne (6c)
1H NMR (400 MHz, CDCl3): d = 0.93 (t, J = 7.3 Hz, 3 H,
CH3), 1.34–1.39 (m, 4 H, CH2), 1.47–1.51 (m, 2 H, CH2),
2.33 (q, J = 7.5 Hz, 2 H, CH2), 6.22 (t, J = 7.5 Hz, 1 H, CH),
7.33–7.37 (m, 3 H, ArH), 7.47–7.50 (m, 2 H, ArH) ppm.
13C NMR (100 MHz, CDCl3): d = 13.9, 22.4, 27.8, 29.3,
31.4, 86.5, 88.2, 113.7, 122.2, 128.3, 128.8, 131.7, 137.9
ppm. 119Sn NMR (150 MHz, CDCl3): d = –28.96 ppm.
HRMS: m/z calcd for C15H17 [M – Cl]+: 197.1325; found:
197.1296.
(26) Representative Procedure for Stille Couplings
In an oven-dried Schlenk tube PdCl2(PhCN)2 (3.8 mg, 5
mol%) was dissolved in DMF (2.0 mL) under Ar. To this
solution 1-chloro-1-iodo-1-octene (4d, 54.0 mg, 0.2 mmol)
was added, followed by the dropwise addition of vinyl
tributyltin (70 mL, 0.22 mmol) at r.t. After 30 min the
reaction was complete (TLC), and the reaction mixture was
diluted with Et2O, washed with sat. NH4Cl solution and H2O.
The organic layer was separated and dried over Na2SO4 and
the crude product obtained after evaporation of the solvent
was purified by silica gel column chromatography using
hexane as eluent.
(Z)-1-Chloro-1-phenyl-1-octene (8d)
1H NMR (400 MHz, CDCl3): d = 0.92 (t, J = 7.0 Hz, 3 H,
CH3), 1.29–1.42 (m, 6 H, CH2), 1.50–1.56 (m, 2 H, CH2),
2.41 (q, J = 7.1 Hz, 2 H, CH2), 6.16 (t, J = 6.6 Hz, 1 H, CH),
7.31–7.38 (m, 3 H, ArH), 7.57–7.60 (m, 2 H, ArH) ppm. 13
C
NMR (100 MHz, CDCl3): d = 14.0, 22.6, 28.5, 29.0, 29.6,
31.7, 126.3, 128.1, 128.2, 128.8, 132.6, 138.4 ppm. HRMS:
m/z calcd for C14H19 [M – Cl]+: 187.1481; found: 187.1482.
1,1-Diphenyl-1-octene (9d)
1H NMR (400 MHz, CDCl3): d = 0.89 (t, J = 6.8 Hz, 3 H,
CH3), 1.23–1.44 (m, 6 H, CH2), 1.46–1.48 (m, 2 H, CH2),
2.14 (q, J = 7.3 Hz, 2 H, CH2), 6.11 (t, J = 7.5 Hz, 1 H, CH),
7.19–7.41 (m, 6 H, ArH), 7.45–7.49 (m, 2 H, ArH), 7.61–
7.64 (m, 2 H, ArH) ppm. 13C NMR (100 MHz, CDCl3):
d = 14.0, 22.6, 28.9, 29.7, 29.9, 31.7, 126.7, 126.8, 127.2,
127.3, 128.0, 128.1, 128.8, 129.9, 130.4, 140.3, 141.2,
141.4, 142.9 ppm. HRMS: m/z calcd for C20H24 [M]+:
264.1873; found: 264.1843.
(Z)-3-Chloro-1,3-decadiene (7d)28
1H NMR (400 MHz, CDCl3): d = 0.91 (t, J = 6.3 Hz, 3 H,
CH3), 1.29–1.37 (m, 6 H, CH2), 1.40–1.46 (m, 2 H, CH2),
2.33 (q, J = 7.3 Hz, 2 H, CH2), 5.16 (d, J = 11.8 Hz, 1 H,
CH), 5.57 (d, J = 15.8 Hz, 1 H, CH), 5.79 (t, J = 7.3 Hz, 1 H,
CH), 6.39 (dd, J = 11.8, 15.8 Hz, 1 H, CH) ppm. 13C NMR
(100 MHz, CDCl3): d = 14.0, 22.6, 28.4, 28.8, 28.9, 31.6,
115.0, 131.9, 132.4, 134.6 ppm.
(28) Mitani, M.; Kobayashi, Y.; Koyama, K. J. Chem. Soc.,
Perkin Trans. 1 1995, 653.
(27) Representative Procedure for Suzuki Couplings
A solution of phenylboronic acid (26.4 mg, 0.22 mmol) in
Synlett 2010, No. 20, 3073–3077 © Thieme Stuttgart · New York

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