Synthesis of cis-vinyltrimethylstannanes and cis-vinylpinacolboronates in a two-step highly regio and stereoselective process

Article abstract of DOI:10.1016/j.tet.2009.06.092

A highly efficient two-step regio and stereoselective method for the synthesis of both cis-vinyltrimethylstannanes and cis-vinylpinacolboronates is described. This method takes advantage of the known lithium/tellurium exchange pathway providing a versatil

Full text of DOI:10.1016/j.tet.2009.06.092

Tetrahedron 65 (2009) 8297–8305
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Synthesis of cis-vinyltrimethylstannanes and cis-vinylpinacolboronates
in a two-step highly regio and stereoselective process
*
Paul Malek Mirzayans, Rebecca H. Pouwer, Craig M. Williams , Paul V. Bernhardt
School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, 4072, Queensland, Australia
a r t i c l e i n f o
a b s t r a c t
Article history:
A highly efficient two-step regio and stereoselective method for the synthesis of both cis-vinyl-
trimethylstannanes and cis-vinylpinacolboronates is described. This method takes advantage of the known
lithium/tellurium exchange pathway providing a versatile alternative to known literature methods. The
methodology presented demonstrates compatibility, for example, with substrates bearing oxygen func-
tionality in comparison to previously reported methods of cis-selective hydrostannylation (i.e., ZrCl4).
Ó 2009 Elsevier Ltd. All rights reserved.
Received 11 March 2009
Received in revised form 2 June 2009
Accepted 19 June 2009
Available online 30 June 2009
1. Introduction
oxygen functionality in the synthesis of cis-vinylstannanes. Un-
fortunately, most of these methods suffer from limitations, e.g., high
The ability to synthesize conjugated systems bearing a variety of
functionality in a highly stereo-selective fashion is of central impor-
tance to synthetic organic chemistry. An excellent illustration of the
need to drive the development of such methodology can be found in
cost,9 substrate dependence in order to exhibit high (Z)-stereo-
selectivity,11,12 and loss of stereochemistry in isolated cases.7a In the
case of cis-vinylboronates, a limited number of synthetic methods
are available which have seen varying degrees of utilization. For ex-
ample, 1) hydrogenation,13 hydroboration14 or hydrozirconation15 of
1-alkynylboranes; 2) hydroboration16 of acetylenes and 1-alkynyl-
bromides17; and 3) Peterson type olefination of aldehydes.18,19
Furthermore, in the case of di- and tri-stannylation and boration, the
high control over stereochemistry is often lost.7c,20
Considering that the hydrotelluration of alkynes occurs in
a highly selective anti fashion to give cis-vinyltellurides that are not
susceptible to isomerisation,21 and also undergo transmetalation to
give cis-vinyl metallated species (i.e., lithium, copper, zinc, mag-
nesium, aluminium, calcium, and sodium) with retention of con-
figuration,22 we wondered whether this pre-existing methodology
could be translated into a new synthetic method for cis-vinyl-
stannanes and cis-vinylboronates. A vital pre-requisite of any new
methodolgy in this area, in addition to being practical, reliable and
stereoselective, would be accommodation of oxygen functionality.
Results of these endeavours are now reported herein.23
the relative under-use of the 6p-electrocyclisation of 1,3-(Z)-5-hex-
atrienes in strategic synthesis.1,2 Though not the sole factor, synthetic
difficulties in obtaining the requisite 1,3-(Z)-5-hexatrienes in reliable
yield and with high stereo-control have certainly limited the utilityof
such a reaction. To date, cis-vinylstannane and cis-vinylboronate re-
agents have played a major role in the construction of Z-conjugated
systems via transition metal catalyzed cross coupling reactions, i.e.,
the Stille3 and Suzuki4 reactions, respectively.5 Unfortunately,
methods to access cis-vinylstannanes and cis-vinylboronates are not
numerous and frequently have problems associated with poor ster-
eoselectivity and functional group tolerance. Over the decades cis-
vinylstannanes have been most commonly synthesized by radical,6
Lewis acid,7 and transition metal8 mediated hydrostannylation of
alkynes, hydrozirconation9 of stannyl alkynes, and by the trans-
metallation of vinyl metallic substrates.10 The use of the Lewis acid
catalyst ZrCl4 in the hydrostannylation of alkynes has found consid-
erable popularity,7b mainly due to the reaction proceeding in an en-
tirely cis-selective fashion. Compatibility of ZrCl4 with oxygen
containing functionality, however, is poor (i.e., Lewis acid co-
ordination), althoughthiscanberemediedwithintroductionofbulky
substituents on oxygen (i.e., TBDMS).7b This solution, however, has
not proven to be a general method in order to circumvent the prob-
lem.5 To date, only a few methods have been reported to tolerate
2. Results and discussion
A variety of alkynes (i.e., 1) (Table 1, 25–34) were treated with
dibutyl ditelluride 2 and sodium borohydride under standard con-
ditions21,22 to give cis-vinyltellurides (i.e., 3) in 58–94% yield (Table 1,
35–43) (Scheme 1). For all conjugated alkynes, the cis-vinyltellurides
were obtained with excellent regio- and stereo-selectivity. Isolated
terminal alkyne 34 (Table 1, Entry 10), however, suffered loss of
regioselectivity yielding 1,2- and 2,2-disubstituted vinylic tellurides
44 and 45, in favour of the 1,2-disubstituted vinylic telluride 44, as
* Corresponding author.
E-mail address: c.williams3@uq.edu.au (C.M. Williams).
0040-4020/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2009.06.092

8298
P.M. Mirzayans et al. / Tetrahedron 65 (2009) 8297–8305
previously documented for isolated alkynes.21,24,25 Unfortunately, in
ourcase, aninseparablemixturewasobtained. Efficientmethodology
to circumvent this problem, however, has been reported to regiose-
lectively give the 1,2-disubstituted cis-vinylic tellurides by hydro-
boration or hydrometallation of 1-alkynyltellurides.26
The cis-vinyltellurides 3 were facilely transmetallated with
n-butyllithium in anhydrous tetrahydrofuran (THF) to the corre-
sponding vinyl lithium intermediate 4, and subsequently quenched
with trimethyltin chloride to afford the cis-vinyl stannanes (i.e., 5)
in 40–68% yield without any detectable amount of trans-vinyl
stannanes (Table 1, 46–54) (Scheme 1) (See Fig. 1A for the X-ray
crystal structure of compound 52, which has crystallographic in-
version symmetry). Purification of the cis-vinylstannanes posed
a challenge as dibutyltelluride 7 was very difficult to remove by
distillation or by column chromatography when certain non-polar
and/or low molecular weight cis-vinyltrimethylstannanes 5 were
Table 1
cis-Vinylbutyltellurides, cis-vinyltrimethylstannanes and cis-vinylpinacolboronates
Entry
1
Acetylene
R–Te–Bu
Yield (%)
RSnMe3
Yield (%)
46
RB (pin)
Yield (%)
i
i
O Pr
i
O Pr
O Pr
67
d
d
SnMe3
TeBu
25
35
46
OMe
OMe
OMe
OMe
OMe
OMe
OMe
OMe
2
71
68
65
B
O
O
55
TeBu
SnMe3
26
36
47
i
PrO
OMe
i
i
PrO
OMe
i
PrO
OMe
PrO
OMe
3
4
84
61
60
50
54
65
B
O
O
O
SnMe3
56
TeBu
27
37
48
B
O
57
SnMe3
TeBu
28
38
49
5
6
78
94
68
61
72
70
B
O
O
SnMe3
58
TeBu
TeBu
29
39
50
CF3
CF3
CF3
CF3
B
O
SnMe3
59
O
30
40
51
O
B
O
7
80
40
22
SnMe3
Me3Sn
TeBu
TeBu
BuTe
B
O
O
60
31
41
O
52
O
O
O
O
O
O
O
8
9
82
58
64
50
72
75
O
B
O
61
SnMe3
32
42
53
B
O
62
TeBu
SnMe3
54
O
33
43
OBn
TeBu
OBn
44
10
42
d
d
d
d
34
BuTe
OBn
45

P.M. Mirzayans et al. / Tetrahedron 65 (2009) 8297–8305
SnMe3
8299
NaBH4
EtOH
R
R
SnMe3
R
R
TeBu
MeI
+
Bu-Te-Te-Bu
R
H
H
+ Bu2Te
7
+ Bu2TeMeI
8
5
5
1
2
3
Scheme 2.
nBuLi
Li
by Brown29 and Stefani30 et al., however, for comparison when THF
was used inthecaseof60, the sameresultwasobtained. Owingtothe
higher polarity of the cis-vinylboranes, column chromatography was
sufficient for removal of the dibutyl telluride 7. Methyl iodide was
used, in this case, in order to scavenge for isopropoxide. [See Figure 1
(B–D) for X-ray crystal structure analysis of compounds 55, 59 and
60]. Interestingly, in some cases, trace amounts of cis-vinyltellurides
3 were recovered, regardless of conditions. This proved to be most
significant for the synthesis of cis-vinylpinacolboronate 56, from
which 25% of the cis-vinyltelluride 37 was recovered.
ClSnMe3
THF
R
R
R
R
SnMe3
+ Bu2Te
+
7
6
5
4
O
iPrO
B
O
O
B
O
+
Diethyl ether
Scheme 1.
6
9
Recently, a mechanistic study of the synthesis of potassium
trans-vinyltrifluoroborate salts, from cis-vinyltellurides via cis-
vinylboronates, has been reported by Stefani et al.30 In view of the
historically characteristic cis-selectivity of the tellurium–lithium
exchange, a free radical pathway has been proposed to account for
the trans-selectivity of this system (Scheme 3). It was suggested
that the loss of stereochemistry was caused by a n-butyl radical 11,
generated from the homolytic cleavage of dibutyl telluride 7, caused
by lithium species present in the reaction medium. Attack of the
anionic complex 10 by 11, generates boronate 12 and a vinyl radical
13, isomerisation of which affords radical 14 leading to the trans-
selectivity observed.
In the view of our results, we were led to consider an ionic mecha-
nism to account for the retention of cis-selectivity in our system. We
postulated that substitution of butyl lithium for hexyl lithium, in the
tellurium–lithium exchange reaction, would generate a butyl-hexyl-
telluride 18, which in turn could give a butyl 11 or hexyl 24 radical in
a free radical approach. Byanalogy to Scheme 3 (n-BuBF3Ksalt16)these
being produced. An efficient method was devised which capitalized
on the known reactivity of dibutyl telluride 7 with methyl iodide to
give methyl di-n-butyltelluronium iodide
8 under catalysed
(AgNO3, AgBF4)27 and non-catalysed conditions.28 When excess
methyl iodide (6 equiv) was added to the reaction mixture after
trimethyltin chloride, it selectively reacted with the dibutyl tellu-
ride 7 affording telluronium salt 8, which could be readly removed
by trituration, followed by column chromatography (Scheme 2).
Initial transmetallation investigations involving tributyltin chloride
were shown to proceed smoothly to afford the tributylvinyl-
stannane derivatives, however, purification by distillation proved
difficult so the study focused on trimethylstannanes.
Treatment of the cis-vinyltellurides 3 with n-butyllithium, fol-
lowed by iso-propoxypinacolboronate afforded the desired cis-
vinylboronates in 22–75% yield, again without any detectable
amount of the trans-isomer (Table 1, compounds 55–62) (Scheme 1).
Reactions were performed in diethyl ether based on results obtained
Figure 1. ORTEP views of crystallographically characterized compounds 52 (A), 55 (B, one of the two independent molecules shown), 59 (C) and 60 (D), (30% probability ellipsoids).
For the structures of 59 and 60 which exhibiting disorder in the boronic ester and/or –CF3 groups, a single conformation is shown (see Electronic Supplementary data for diagrams
showing all contributors to disorder).

8300
P.M. Mirzayans et al. / Tetrahedron 65 (2009) 8297–8305
R
R
BuLi
n-Bu2Te
+
Et2O, -78 °C
TeBu
Li
3
4
7
B(OiPr)3
-20 °C
R
n-Bu
11
n-BuTe
+
B(OiPr)3
10
- n-BuB(OiPr)3
12
R
B(OiPr 3
n-BuTe
)
R
R
BF3K
+
KHF2
16
BF3K
13
14
15
Scheme 3.
radical species would give rise to a mixture of n-butyl and n-hexyl-
pinacolboronates 22 and 23 respectively (Scheme 4).
with small amounts of the corresponding alkene, starting material 37,
and hexane. Interestingly, trace amounts of dihexyltelluride and Z-
b-
However, when carrying out the reaction using hexyl lithium and
Z-b-(butyltelluro)-2-isopropoxy-3-methoxystyrene (37) under stan-
(hexyltelluro)-2-isopropoxy-3-methoxystyrene were also observed.
It should be noted that in addition to the different boronate used in
our system, boronates were added at ꢀ78 ꢁC as compared to ꢀ20 ꢁC
in the synthesis of potassium trans-vinyltrifluoroborate salts30
(Scheme 4). Although radicals cannot be ruled out, our results suggest
that such a pathway is not in effect under our reaction conditions,
hence, the preserved cis-selectivity in our system.
dard conditions, vinylboronate 56 and butyl-hexyl-telluride 18 were
observedbyGC–MStobethemajorproducts.Asexpected, ratherthan
a mixture of 22, 23 and 21 only a small amount of n-hex-
ylpinacolboronate 23, believed to be formed by the direct addition of
hexyl lithium to iso-propoxypinacolboronate, was observed along
O
O
nHexLi
nBu-Te-nHex
+
Et2O, -78 °C
O
O
18
TeBu
Li
37
17
O
-78 °Cto r.t.
B
O
O
nBu
nHexTe
O
O
O
-78 °C to r.t.
11
+
O
nButTe
nHex
- (OiPr)Bpin-nHex
- (OiPr)Bpin-nBu
Bpin(OiPr)
24
20
19
O
O
O
B
O
B
O
O
nBu
nHex
B
O
O
22
23
21
Scheme 4.

P.M. Mirzayans et al. / Tetrahedron 65 (2009) 8297–8305
8301
The bis-systems (i.e., 52 and 60), derived from 1,4-diethynyl-
benzene 31, were of particular interest for application to the con-
struction of conjugated polyenes via tandem bis-Stille or -Suzuki
reactions. Distannane 52 was isolated in moderate yield with
complete retention of stereochemical integrity. [see X-ray crystal
structure analysis (Fig. 1A)] Excellent stereo-control was again
obtained in the case of the bis-boronate 60 [see X-ray crystal
structure analysis (Fig. 1D)], but the yield was much lower and
could not be improved by standard variations in conditions.
Compound 55 crystallized with two independent molecules,
with no significant differences in the unit cell (Fig. 1B). The struc-
tures of compounds 59 and 60, however, were plagued by disorder
of the boronic ester groups. As shown in ESI Fig. S1, the 5-mem-
bered rings were disordered between three different puckered
conformations. In addition, the trifluoromethyl group in 59 was
disordered between two rotamers. The lack of H-bond donors and
the presence of the bulky methyl groups attached to the five-
membered rings enables the boronic ester groups to adopt a num-
ber of conformations without disturbing the overall packing within
the structure. The disorder lowered the precision of the structures
of compounds 59 and 60 as a consequence. Compound 60 (like 52)
also has crystallographic inversion symmetry.
Crystallographic data for structures 52, 55, 59 and 60 have been
deposited with the Cambridge Crystallographic Data Centre (CCDC
708676–708679) and may be obtained free of charge via http://
www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ,
UK; fax: þ44 1223 336 033, or e-mail: deposit@ccdc.cam.ac.uk.
3.2. Dibutyl ditelluride (2)
To a suspension of tellurium powder (3 g, 23.5 mmol, 200 mesh)
in anhydrous tetrahydrofuran (30 mL) at 0 ꢁC under an argon at-
mosphere was added n-butyllithium (15.9 mL, 1.48 M in hexanes,
23.5 mmol) drop-wise. The reaction was stirred for 35 min at 0 ꢁC
and an additional 15 min at rt after which time the mixture was
poured into an Erlenmeyer flask containing water (60 mL). After
stirring for 20 min under air the organic phase was separated and
the aqueous phase was extracted with ethyl acetate. The combined
organic phase was washed with saturated ammonium chloride
solution, brine, dried over magnesium sulphate, and filtered
through a plug of Celite. The solvent was removed in vacuo to yield
the title compound (3.96 g, 91%) as a red oil. 1H NMR (300 MHz)
d
ppm 0.91 (t, J¼7.3 Hz, 6H), 1.40 (mc, 4H), 1.63–1.75 (m, 4H), 3.09
In conclusion, a new versatile method for the synthesis of cis-
vinyltrimethylstannanes and cis-vinylpinacolboronates in a two-step,
highly regio- and stereoselective manner has been disclosed, which
buildsonthewell knowntellurium–lithium metalexchange protocol.
In the case of cis-vinyltrimethylstannanes, this method offers ad-
vantages over other popular methods when oxygen functionality is
required. cis-Vinyl tellurides offer increasing potential as synthetic
reagents,31 and further work in this area is currently underway.
(mc, 4H). 1H NMR and all other spectroscopic data were identical to
that previously reported.22b
3.3. General procedure for the preparation of
cis-vinyltellurides
The procedure described for the preparation of Z-b-(butyltelluro)-
4-trifluoromethylstyrene (40) is representative. Dibutylditelluride
(540 mg, 1.46 mmol) and 1-ethynyl-4-(trifluoromethyl)benzene (30)
(0.454 mL, 2.78 mmol) were suspended in anhydrous ethanol (8 mL)
under an argon atmosphere. Sodium borohydride (110 mg, 2.92 mmol)
was added portion-wise and the solution became yellow in colour. The
reaction was then heated to reflux, and further portions of sodium
borohydride were added to keep the mixture yellow in colour. After 3 h,
the reaction was quenched by the addition of water (3 mL) and 10%
sodium hydroxide solution (3 mL). The mixture was extracted with
petroleum ether and the combined organic phase was washed with
brine and dried over magnesium sulfate. The solvent was removed in
vacuo and the residue was purified by silica gel column chromatogra-
phy (petroleum ether) to yield the title compound (932 mg, 94%) as
3. Experimental section
3.1. General experimental
1H and 13C NMR spectra were recorded on Bruker AV400
(400.13 MHz; 100.62 MHz), AV300 (300.13 MHz; 75.47 MHz) and
DRX500 (500.13 MHz; 125.76 MHz) instruments in deuterio-
chloroform (CDCl3). Coupling constants are given in Hz and
chemical shifts are expressed as
d values in ppm. Hydrogen–tin
couplings are reported when possible and are in accordance with
what has been previously reported for similar compounds.32 High
resolution electron impact ionization (HREIMS) accurate mass
measurements were recorded on a Finnigan MAT 900XL-TRAP (EI
70 eV) using perfluorokerosene-H as reference calibrant. High
resolution electrospray ionisation (HRESIMS) accurate mass mea-
surements were recorded in positive mode on a Bruker MicrOTOF-
Q (quadrupoledTime of Flight) instrument with a Bruker ESI
source using sodium formate as a reference calibrant. IR spectra
were measured on a Perkin–Elmer FT-IR spectrometer (Spectrum
2000) with a Smiths detection (DuraSamplerIR II). Microanalyses
were performed by the University of Queensland Microanalytical
Service. Column chromatography was undertaken on silica gel
(Flash Silica gel 230–400 mesh) or active neutral aluminium oxide
(Brockman grade 1) with distilled solvents. All reagents and sol-
vents were distilled according to Perin and Armarego, ‘Purification
of laboratory chemicals’, 3rd ed. prior to use. Tetrahydrofuran was
freshly distilled from a sodium/benzophenone still. Melting points
were determined on a Stuart SMP11 Melting Point apparatus and
are uncorrected. Dibutyl ditelluride can be purchased from ACROS
chemical company, however, it was readily prepared, see below.
Vinyltellurides were placed under vacuum with gentle stirring
overnight prior to use. Toxicity and pharmacology information of
organotellurium compounds has been reported.33 Fine chemicals
were purchased from the Aldrich Chem. Co. hexyl lithium was
prepared according to literature procedure.34
a yellow oil. 1H NMR (400 MHz)
d
ppm 0.92 (t, J¼7.4 Hz, 3H), 1.40 (mc,
2H), 1.77–1.86 (m, 2H), 2.76 (mc, 2H), 7.19 (d, J¼10.9 Hz, 1H), 7.33–7.38
(m, 2H), 7.39 (d, J¼10.9 Hz, 1H), 7.59 (d, J¼8.2 Hz, 2H). 13C NMR
(100 MHz) 9.6, 13.4, 24.9, 33.9, 109.0, 124.2 (q, 1JCF¼271.9 Hz), 125.3 (q,
3JCF¼3.8 Hz), 127.7, 128.9 (q, 2JCF¼32.5 Hz), 135.5, 142.4. HRMS (EI) Cal-
culated for C13H15F3Te: Mþ 358.0183. Found: 358.0195. IR
2960, 2929, 2873, 1614, 1404, 1321, 1162, 1113, 1065, 847.
n )
(cmꢀ1
ꢂ
3.4. Z-b-(Butyltelluro)-4-isopropoxystyrene (35)
The title compound was prepared as indicated in the repre-
sentative procedure. The reaction was quenched after 20 h. Purifi-
cation by silica gel column chromatography (15:1, petroleum ether/
diethyl ether) yielded the title compound (35 mg, 67%) as a yellow
oil. 1H NMR (300 MHz)
d
ppm 0.91 (t, J¼7.3 Hz, 3H), 1.32 (d,
J¼6.1 Hz, 6H), 1.40 (mc, 2H), 1.74–1.86 (m, 2H), 2.71 (mc, 2H), 4.53
(sept., J¼6.1 Hz, 1H), 6.79 (d, J¼10.7 Hz, 1H), 6.82–6.90 (m, 2H),
7.14–7.22 (m, 2H), 7.30 (d, J¼10.7 Hz, 1H). 13C NMR (125 MHz) 8.9,
13.4, 22.1, 25.0, 30.9, 34.0, 69.9, 102.1, 115.6, 129.0, 131.5, 136.5, 157.1.
HRMS (EI) Calculated for C15H22OTe: Mþ 348.0727. Found:
ꢂ
348.0734. IR
1244, 1180, 1108, 953, 835.
n
(cmꢀ1) 2974, 2926, 2871, 1605, 1563, 1504, 1297,

8302
P.M. Mirzayans et al. / Tetrahedron 65 (2009) 8297–8305
3.5. Z-
b
-(Butyltelluro)-3,4-dimethoxystyrene (36)
n
(cmꢀ1) 3019, 2951, 2922, 2868, 2837, 1581, 1505, 1460, 1403, 1338,
1304, 1246, 1187, 1161, 827.
The title compound was prepared as indicated in the repre-
sentative procedure. The reaction was quenched after 18 h. Purifi-
cation by silica gel column chromatography (5:1, petroleum ether/
diethyl ether) yielded the title compound (543 mg, 71%) as a yellow
3.10. (Z)-[2-(1,4-Dioxaspiro[4,5]dec-7-en-8-yl)-
vinyl]butyltelluride (42)
oil. 1H NMR (300 MHz)
d
ppm 0.91 (t, J¼7.3 Hz, 3H), 1.40 (mc, 2H),
The title compound was prepared as indicated in the repre-
sentative procedure. The reaction was quenched after 20 h. Purifi-
cation by silica gel column chromatography (14:1, petroleum ether/
diethyl ether) yielded the title compound (3.0 g, 82%) as a red/
1.75–1.87 (m, 2H), 2.73 (mc, 2H), 3.87 (s, 3H), 3.89 (s, 3H), 6.79–6.88
(m, 3H), 6.83 (d, J¼10.6 Hz, 1H), 7.30 (d, J¼10.6 Hz, 1H). 13C NMR
(75 MHz) 9.0, 13.4, 25.0, 34.0, 55.9, 103.0, 110.4, 111.0, 120.6, 132.2,
136.5, 148.3, 148.8. HRMS (ESI) Calculated for C14H20O2TeNaþ:
yellow oil. 1H NMR (400 MHz)
d
ppm 0.90 (t, J¼7.4 Hz, 3H), 1.37 (mc,
373.0418. Found: 373.0418. IR
n
(cmꢀ1) 2855, 2927, 2834, 1593,
2H), 1.72–1.82 (m, 4H), 2.33–2.39 (m, 2H), 2.43 (mc, 2H), 2.63 (mc,
2H), 3.96–3.97 (m, 4H), 5.53 (mc, 1H), 6.52 (d, J¼10.7 Hz, 1H), 6.78
(d, J¼10.7 Hz, 1H). 13C NMR (100 MHz, CDCl3) 8.8, 13.4, 25.0, 26.7,
30.8, 33.9, 35.9, 64.4, 101.2, 107.7, 125.0, 136.8, 138.3. MS (EI): m/z
352 (21), 350 (19), 348 (12), 295 (27), 293 (25), 291 (16), 251 (14),
249 (13), 209 (39), 207 (37), 205 (21), 166 (11), 165 (100), 99 (15), 93
(16), 91 (14), 79 (40), 77 (18). HRMS (EI) Calculated for C14H22O2Te:
1509, 1460, 1257, 1235, 1169, 1134, 1024.
3.6. Z-b-(Butyltelluro)-2-isopropoxy-3-methoxystyrene (37)
The title compound was prepared as indicated in the represen-
tative procedure. The reaction was quenched after 5.5 h. Purification
by silica gel column chromatography (25:1, petroleum ether/diethyl
ether) yielded the title compound (360 mg, 84%) as a yellow oil. 1H
Mþꢂ 352.0681. Found: 352.0681. IR (cmꢀ1) 2955, 2925, 2873, 1629,
n
1566, 1460, 1446, 1429, 1367, 1321, 1248, 1109, 1058, 947, 867.
NMR (400 MHz)
d
ppm 0.90 (t, J¼7.4 Hz, 3H), 1.24 (d, J¼6.2 Hz, 6H),
3.11. Z-(2-Cyclohexenyl-1-ethenyl)butyltelluride36 (43)
1.38 (mc, 2H), 1.73–1.82 (m, 2H), 2.67 (mc, 2H), 3.82 (s, 3H), 4.34
(sept., J¼6.2 Hz, 1H), 6.83 (dd, J¼8.1, 1.5 Hz, 1H), 6.86–6.90 (m, 1H),
6.95 (d, J¼10.7 Hz, 1H), 7.02 (t, J¼7.9 Hz, 1H), 7.53 (d, J¼10.7 Hz, 1H).
13C NMR (100 MHz) 8.2,13.4, 22.5, 24.9, 34.0, 55.8, 75.6,106.2,111.9,
119.3, 123.2, 133.9, 134.5, 144.7, 153.1. HRMS (EI) Calculated for
The title compound was prepared as indicated in the repre-
sentative procedure. The reaction was quenched after 6 h. Purifi-
cation by silica gel column chromatography (petroleum ether)
yielded the title compound (282 mg, 58%) as a yellow/orange oil. 1H
C16H24O2Te: Mþ$ 378.0833. Found: 378.0838. IR
1588, 1569, 1471, 1449, 1378, 1276, 1256, 1213, 1106, 1067, 933, 779.
n
(cmꢀ1) 2960, 2927,
NMR (400 MHz)
d
ppm 0.90 (t, J¼7.3 Hz, 3H), 1.38 (mc, 2H), 1.53–
1.68 (m, 4H), 1.72–1.82 (m, 2H), 2.07–2.14 (m, 2H), 2.14–2.20 (m,
2H), 2.62 (mc, 2H), 5.63 (mc, 1H), 6.45 (d, J¼10.6 Hz, 1H), 6.73 (dd,
J¼10.6, 0.7 Hz, 1H). 13C NMR (75 MHz) 8.6, 13.4, 22.1, 22.5, 25.0,
3.7. Z-b
-(Butyltelluro)styrene35 (38)
25.5, 27.6, 34.0, 99.9, 128.2, 137.5, 139.6. IR
1435, 1324, 1247, 1165, 848.
n
(cmꢀ1) 2924, 1565,
The title compound was prepared as indicated in the repre-
sentative procedure. The reaction was quenched after 2.5 h. Puri-
fication by silica gel column chromatography (petroleum ether)
yielded the title compound (343 mg, 61%) as a yellow oil. 1H NMR
3.12. Z-b-(Butyltelluro)-5-benzyloxy-1-pentenyl (44)
and 2-butyltelluro-5-benzyloxy-1-pentenyl (45)
(400 MHz)
d
ppm 0.91 (t, J¼7.4 Hz, 3H), 1.40 (mc, 2H), 1.76–1.85 (m,
2H), 2.72 (mc, 2H), 6.98 (d, J¼10.8 Hz, 1H), 7.20–7.28 (m, 3H), 7.32–
The title compound was prepared as indicated in the repre-
sentative procedure. The reaction was quenched after 21 h. Purifi-
cation by silica gel column chromatography (20:1, petroleum ether/
7.37 (m, 2H), 7.37 (d, J¼10.8 Hz, 1H). 13C NMR (100 MHz) 9.0, 13.4,
25.0, 34.0, 105.3, 127.3, 127.6, 128.4, 136.9, 139.0. IR
n
(cmꢀ1) 2956,
2925, 2870, 1597, 1492, 1442, 1329, 1247, 1167, 769, 696.
diethyl ether) yielded an inseparable mixture of
tellurides in the ratio 1:1.6 (392 mg, 42%) as a yellow oil. 1H NMR
(400 MHz)
a and b-vinyl-
3.8. Z- -(Butyltelluro)-4-methylstyrene (39)
b
d
ppm 0.91 (t, J¼7.4 Hz, 6H), 1.38 (mc, 4H), 1.68–1.87 (m,
8H), 2.09–2.16 (m, 2H), 2.41 (br t, J¼7.5 Hz, 2H), 2.66 (mc, 2H), 2.73
(mc, 2H), 3.48 (t, J¼6.3 Hz, 2H), 3.48 (t, J¼6.5 Hz, 2H), 4.49 (s, 2H),
4.49 (s, 2H), 5.37 (t, J¼0.6 Hz, 1H), 5.88 (t, J¼1.5 Hz, 1H), 6.17 (dt,
J¼6.9, 9.3 Hz, 1H), 6.57 (dt, J¼1.2, 9.3 Hz, 1H), 7.24–7.30 (m, 5H),
7.31–7.36 (m, 5H). 13C NMR (100 MHz) 6.0, 6.4, 13.4, 24.9, 25.2, 28.8,
29.5, 32.3, 33.7, 34.2, 39.3, 69.1, 69.6, 72.9 (m), 103.2, 122.8, 126.6,
The title compound was prepared as indicated in the repre-
sentative procedure. The reaction was quenched after 5.5 h. Puri-
fication by silica gel column chromatography (petroleum ether)
yielded the title compound (638 mg, 78%) as a yellow oil. 1H NMR
(300 MHz)
d
ppm 0.91 (t, J¼7.3 Hz, 3H), 1.39 (mc, 2H), 1.73–1.87 (m,
127.5 (m), 127.6 (m), 128.3, 138.5, 138.6, 139.6. IR
2927, 2855, 1599, 1101, 733, 696, 617.
n
(cmꢀ1) 2956,
2H), 2.32 (s, 3H), 2.71 (mc, 2H), 6.90 (d, J¼10.7 Hz, 1H), 7.15 (s, 4H),
7.34 (d, J¼10.7 Hz, 1H). 13C NMR (75 MHz) 8.9, 13.4, 21.3, 25.0, 34.0,
104.0, 127.5, 129.0, 136.2, 136.8, 137.1. IR n
(cmꢀ1) 3019, 2956, 2924,
2869, 1587, 1507, 1458, 1330, 1181, 1167, 817.
3.13. Methyl di-n-butyltelluronium iodide (8)
3.9. 1,4-Bis[(Z)-2-(butyltelluro)vinyl]benzene (41)
Methyl di-n-butyltelluronium iodide was isolated as a white
amorphous solid, mp 93–95 ꢁC (lit. 94 ꢁC37). 1H NMR (400 MHz)
The title compound was prepared as indicated in the repre-
sentative procedure. The reaction was quenched after 4.5 h. Puri-
fication by silica gel column chromatography (250:1, petroleum
ether/diethyl ether) yielded the title compound (361 mg, 80%) as
d
ppm 0.97 (t, J¼7.3 Hz, 6H),1.47 (mc, 4H),1.74–1.87 (m, 4H), 2.32–2.41
(m, 3H), 3.05(mc, 4H).13CNMR(100 MHz)5.7,13.5,24.6,26.7, 27.9. IR
(cmꢀ1) 2958, 2930, 2869, 1460, 1380, 1178, 1091, 897, 843, 772, 700.
n
a yellow solid, mp 34–36 ꢁC. 1H NMR (500 MHz)
d
ppm 0.92 (t,
3.14. General procedure for the preparation
J¼7.4 Hz, 6H), 1.40 (mc, 4H), 1.77–1.85 (m, 4H), 2.73 (mc, 4H), 6.99
(d, J¼10.8 Hz, 2H), 7.26 (s, 4H), 7.35 (d, J¼10.8 Hz, 2H). 13C NMR
(125 MHz) 9.3, 13.4, 25.0, 34.0, 105.5, 127.6, 136.4, 137.8. HRMS (EI)
of cis-vinylstannanes
The procedure described for the preparation of Z-
stannyl)-3,4-dimethoxystyrene (47) is representative. To a solution of
Z- -(butyltelluro)-3,4-dimethoxystyrene (36) (136 mg, 0.391 mmol)
b-(trimethyl-
Calculated for C18H26Te2: Mþ 502.0153. Found: 502.0180. Anal.
ꢂ
Calcd for C18H26Te2: C, 43.45; H, 5.27. Found: C, 43.43; H, 5.13. IR
b

P.M. Mirzayans et al. / Tetrahedron 65 (2009) 8297–8305
8303
in anhydrous tetrahydrofuran (4 mL) at ꢀ78 ꢁC under an argon at-
mosphere was added n-butyllithium (0.319 mL, 1.35 M in hexanes,
0.430 mmol) drop-wise. The reaction was stirred for 10 min before
(petroleum ether) to yield the title compound (65 mg, 50%) as
a
colourless oil. 1H NMR (300 MHz)
d ppm 0.06 (s, 9H,
2
2JSnH¼53.0 Hz/55.4 Hz), 6.18 (d, J¼13.6 Hz, 1H, JSnH¼62.7 Hz/
65.4 Hz), 7.19–7.35 (m, 5H), 7.57 (d, J¼13.6 Hz, 1H). 13C NMR
(75 MHz) ꢀ8.1, 127.3 (m), 128.2, 133.8, 141.1, 147.3.
a
solution of trimethyltin chloride (0.496 mL, 1 M in THF,
0.496 mmol) was added drop-wise. The reaction was stirred for
a further 30 min at ꢀ78 ꢁC then allowed to warm to 0 ꢁC over 2 h.
After reaching 0 ꢁC the reaction mixture was shielded from light,
placed in anice bath, and MeI (0.146 mL, 2.35 mmol) wasadded drop-
wise after which time the ice bath was removed. After stirring for 4 h
at rt the solvent was removed in vacuo and the resulting crude oil was
triturated with petroleum ether/diethyl ether (4:1), the combined
organic phase was concentrated and purified on a plug of neutral
Al2O3 (10:1, petroleum ether/diethyl ether) to yield the title com-
3.18. Z-b-(Trimethylstannyl)-4-methylstyrene (50)
The title compound was prepared as indicated in the repre-
sentative procedure with the following exception. The resulting
crude oil was triturated with petroleum ether, purified on a plug of
neutral Al2O3 (petroleum ether) to yield the title compound
(119 mg, 68%) as a colourless oil. 1H NMR (400 MHz)
d
ppm 0.07 (s,
pound (87 mg, 68%) as a colourless oil.1H NMR (400 MHz)
d
ppm 0.10
9H, JSnH¼53.2 Hz/55.2 Hz), 2.32 (s, 3H), 6.11 (d, J¼13.6 Hz, 1H,
2
2
(s, 9H, JSnH¼52.7 Hz/55.1 Hz), 3.87 (s, 3H), 3.87 (s, 3H), 6.07 (d,
2JSnH¼63.1 Hz/65.4 Hz),40 7.10 (d, J¼8.1 Hz, 2H), 7.14 (d, J¼8.1 Hz,
J¼13.6 Hz, 1H, 2JSnH¼61.6 Hz/64.5 Hz),38 6.77–6.79 (m,1H), 6.80–6.82
2H), 7.52 (d, J¼13.6 Hz, 1H, JSnH¼144.5 Hz/151.0 Hz). 13C NMR
3
3
(m, 2H), 7.49 (d, J¼13.6 Hz, 1H, JSnH¼144.1 Hz/150.8 Hz). 13C NMR
(100 MHz) ꢀ8.1, 21.2, 127.2, 128.9, 132.5, 137.1, 138.2, 147.2. IR
n
1
(100 MHz) ꢀ8.1, ꢀ8.1 (d, JSnC¼338.8 Hz/354.7 Hz), 55.9 (m), 110.2,
(cmꢀ1) 2967, 2918, 1590, 1562, 1508, 1450, 1188, 1113, 821, 761, 733.
HRMS (EI) Calculated for C11H15118Sn: [MꢀMe]þ 265.0190. Found:
265.0196.
110.8, 120.1, 131.4, 134.0, 146.9, 148.6 (m). HRMS (ESI) Calculated for
C13H20O2SnNaþ: 351.0377. Found: 351.0377. IR
n
(cmꢀ1) 2961, 2835,
1600, 1572, 1508, 1461, 1259, 1237, 1130, 1027, 764.
3.19. Z-b-(Trimethylstannyl)-4-trifluoromethylstyrene (51)
3.15. Z- -(Trimethylstannyl)-4-isopropoxystyrene (46)
b
The title compound was prepared as indicated in the represen-
tative procedure with the following exception. The resulting crude oil
was triturated with petroleum ether. Purified on a plug of neutral
Al2O3 (petroleum ether) to yield the title compound (118 mg, 61%) as
The title compound was prepared as indicated in the repre-
sentative procedure with the following exception. The reaction
was allowed to reach rt over a period of 2 h, the solvent was
removed in vacuo and the crude mixture was purified on a short
plug of silica treated with TEA (petroleum ether, 1% TEA) to yield
a colourless oil. 1H NMR (400 MHz)
d
ppm 0.07 (s, 9H, 2JSnH¼53.1 Hz/
55.5 Hz), 6.34 (d, J¼13.8 Hz, 1H, 2JSnH¼58.2 Hz/60.9 Hz), 7.31–7.36 (m,
3
the title compound (43 mg, 46%) as a colourless oil. 1H NMR
2H), 7.53–7.58 (m, 2H), 7.56 (d, J¼13.4 Hz, 1H, JSnH¼137.2 Hz/
2
1
(400 MHz)
d
ppm 0.08 (s, 9H, JSnH¼52.7 Hz/55.2 Hz), 1.32 (d,
143.4 Hz). 13C NMR (100 MHz) ꢀ8.1, ꢀ8.1 (d, JSnC¼342.0 Hz/
J¼6.1 Hz, 6H), 4.53 (sept., J¼6.1 Hz, 1H), 6.04 (d, J¼13.6 Hz, 1H,
358.1 Hz), 124.2 (q, 1JCF¼271.9 Hz), 125.2 (q, 3JCF¼3.8 Hz), 127.5, 129.3
(q, 2JCF¼32.4 Hz),136.9,136.9 (d, 1JSnC¼394.7 Hz/413.3 Hz),144.6 (m),
2JSnH¼62.8 Hz/65.7 Hz), 6.79–6.84 (m, 2H), 7.13–7.18 (m, 2H), 7.49
(d, J¼13.6 Hz, 1H, JSnH¼145.0 Hz/151.8 Hz). 13C NMR (100 MHz)
145.8. IR n
(cmꢀ1) 2974, 1619, 1323, 1163, 1123, 1065, 856, 767. HRMS
3
ꢀ8.1, 22.0, 69.9, 115.6, 128.4, 131.2, 133.6, 146.7, 157.4. HRMS (EI)
(EI) Calculated for C11H12F3Sn: [MꢀMe]þ 265.0190. Found: 265.0196.
Calculated for C13H19OSn: [MꢀMe]þ 311.0452. Found: 311.0449.
IR
n
(cmꢀ1) 2976, 2918, 1606, 1504, 1295, 1243, 1119, 954, 841,
3.20. 1,4-Bis[(Z)-2-(trimethylstannyl)vinyl]benzene (52)
766.
The title compound was prepared as indicated in the repre-
sentative procedure with the following exception. The resulting
crude oil was triturated with petroleum ether, purified on a plug of
silica treated with TEA (petroleum ether, 1% TEA) to yield the title
3.16. Z-
styrene (48)
b-(Trimethylstannyl)-2-isopropoxy-3-methoxy-
The title compound was prepared as indicated in the repre-
compound (40 mg, 40%) as white crystals, mp 53–55 ꢁC. 1H NMR
2
sentative procedure with the following exception. The reaction
was allowed to reach rt over a period of 2 h, the solvent was re-
moved in vacuo and the crude mixture was purified on a short
plug of silica treated with TEA (25:1, petroleum ether/diethyl
(300 MHz)
d
ppm 0.09 (s, 18H, JSnH¼52.9 Hz/55.4 Hz), 6.18 (d,
2
J¼13.7 Hz, 2H, JSnH¼61.3 Hz/64.1 Hz), 7.20 (s, 4H), 7.54 (d,
J¼13.7 Hz, 2H, JSnH¼142.6 Hz/149.3 Hz). 13C NMR (75 MHz) ꢀ8.0,
3
127.2, 133.7, 140.2, 146.9. HRMS (EI) Calculated for C15H23118SnSn:
ether, 1% TEA) to yield the title compound (92 mg, 60%) as a col-
[MꢀMe]þ 440.9929.41 Found: 440.9827. IR
n
(cmꢀ1) 2969, 2912,
ourless oil. 1H NMR (500 MHz)
d
ppm 0.02 (s, 9H, JSnH¼52.9 Hz/
1577, 1501, 1400, 1336, 1185, 857, 760, 721.
2
55.1 Hz), 1.24 (d, J¼6.2 Hz, 6H), 3.81 (s, 3H), 4.40 (sept., J¼6.2 Hz,
2
1H), 6.18 (d, J¼13.6 Hz, 1H, JSnH¼67.9 Hz/71.0 Hz), 6.79–6.85 (m,
3.21. (Z)-[2-(1,4-Dioxaspiro[4,5]dec-7-en-8-yl)-
vinyl]trimethylstannane (53)
3
2H), 6.95 (t, J¼7.9 Hz, 1H), 7.68 (d, J¼13.6 Hz, 1H, JSnH¼145.0 Hz/
151.8 Hz). 13C NMR (125 MHz) ꢀ8.1, ꢀ8.1 (d, JSnC¼338.9 Hz/
1
354.4 Hz), 22.5, 55.8, 75.2, 111.9, 120.2, 123.2, 133.6, 136.5, 144.3,
144.9, 152.8. HRMS (ESI) Calculated for C15H24O2SnNaþ: 379.0696.
The title compound was prepared as indicated in the repre-
sentative procedure with the following exception. The reaction
was allowed to reach rt over a period of 2 h and quenched by the
addition of saturated aqueous NaHCO3. The organic phase was
diluted with Et2O separated and dried over MgSO4. The solvent
was removed in vacuo and the crude mixture was purified by
silica column chromatography, treated with TEA (20:1, petroleum
ether/diethyl ether, 1% TEA) to yield the title compound (120 mg,
Found: 379.0690 IR
1215, 1108, 1069, 769, 746.
n
(cmꢀ1) 2974, 1567, 1471, 1452, 1372, 1274,
3.17. Z-b
-(Trimethylstannyl)styrene39 (49)
The title compound was prepared as indicated in the repre-
sentative procedure with the following exception. After stirring for
4 h at rt the reaction was quenched by the addition of saturated
aqueous NaHCO3. The organic phase was diluted with Et2O sepa-
rated and dried over MgSO4. The solvent was removed in vacuo and
the crude mixture was purified on a plug of neutral Al2O3
64%) as a colourless oil. 1H NMR (400 MHz)
d ppm 0.14 (s, 9H,
2JSnH¼52.5 Hz/54.9 Hz), 1.77 (tt, J¼6.6, 0.8 Hz, 2H), 2.25–2.31 (m,
2H), 2.32–2.36 (m, 2H), 3.97 (s, 4H), 5.55 (mc, 1H), 5.78 (d,
2
J¼13.5 Hz, 1H, JSnH¼63.4 Hz/66.1 Hz), 6.93 (dd, J¼13.5, 0.8 Hz,
1H). 13C NMR (100 MHz) ꢀ7.5, 26.1, 30.9, 36.0, 64.4, 107.8, 124.2,

8304
P.M. Mirzayans et al. / Tetrahedron 65 (2009) 8297–8305
129.2, 139.0, 148.9. HRMS (EI) Calculated for C13H22O2Sn: Mþ
3.25. (Z)-2-(3-Methoxy-2-isopropoxystyryl)-4,4,5,5-
tetramethyl-1,3,2-dioxaborolane (56)
ꢂ
330.0636. Found: 330.0634. IR
n
(cmꢀ1) 2953, 2880, 1634, 1563,
1423, 1368, 1107, 1059, 1044, 871, 766, 719.
The title compound was prepared as indicated in the repre-
sentative procedure. Purification by silica gel column chromatog-
raphy (15:1, petroleum ether/diethyl ether) yielded the title
compound (46 mg, 54%) as a colourless oil. 1H NMR (500 MHz)
3.22. Z-(2-Cyclohexenyl-1-ethenyl)trimethylstannane (54)
The title compound was prepared as indicated in the repre-
sentative procedure with the following exception. The reaction
was allowed to reach rt over a period of 2 h and quenched by the
addition of saturated aqueous NaHCO3. The organic phase was
diluted with Et2O, separated, and dried over MgSO4. The solvent
was removed in vacuo and the crude mixture was purified by
silica column chromatography, treated with TEA (n-pentane, 1%
d
ppm 1.23 (s, 12H), 1.24 (d, J¼6.2 Hz, 6H), 3.81 (s, 3H), 4.36 (sept.,
J¼6.2 Hz, 1H), 5.59 (d, J¼14.9 Hz, 1H), 6.82 (dd, J¼8.1, 1.5 Hz, 1H),
6.92 (t, J¼8.0 Hz, 1H), 7.19 (dd, J¼7.7, 1.4 Hz, 1H), 7.44 (d, J¼14.9 Hz,
1H). 13C NMR (100 MHz) 22.5, 24.8, 55.8, 75.7, 83.2, 112.2, 121.7,
122.6, 134.0, 144.3, 145.3, 152.8. HRMS (ESI) Calculated for
C18H27BO4Naþ: 341.1895. Found: 341.1891. IR
2837, 1619, 1574, 1441, 1253, 1142, 785, 671.
n
(cmꢀ1) 2977, 2934,
TEA) to yield the title compound (60 mg, 50%) as a colourless oil.
2
1H NMR (400 MHz)
d
ppm 0.13 (s, 9H, JSnH¼52.4 Hz/54.9 Hz),
3.26. (Z)-4,4,5,5-Tetramethyl-2-styryl-1,3,2-
1.51–1.68 (m, 4H), 2.00–2.13 (m, 4H), 5.64–5.69 (m, 1H), 5.72 (d,
dioxaborolane (57)42
2
J¼13.4 Hz, 1H, JSnH¼66.9 Hz/69.7 Hz), 6.90 (dd, J¼13.4 Hz, 0.8 Hz,
1H). 13C NMR (100 MHz) ꢀ7.4, 22.2, 22.6, 25.6, 27.1, 127.2, 128.0,
139.7, 150.3. IR
764, 722.
n
(cmꢀ1) 2927, 1633, 1562, 1436, 1187, 1133, 920,
The title compound was prepared as indicated in the repre-
sentative procedure. Purification by silica gel column chromatog-
raphy (30:1, petroleum ether/diethyl ether) yielded the title
compound (153 mg, 65%) as a colourless oil. 1H NMR (500 MHz)
3.23. General procedure for the preparation of cis-
vinylboronates
d
ppm 1.27 (s, 12H), 5.57 (d, J¼14.9 Hz, 1H), 7.20 (d, J¼14.9 Hz, 1H),
7.22–7.31 (m, 3H), 7.50–7.53 (m, 2H). 13C NMR (125 MHz) 24.8, 83.5,
127.9, 128.0, 128.6, 138.5, 148.1. IR
(cmꢀ1) 3058, 3028, 2980, 2933,
n
The procedure described for the preparation of (Z)-2-[2-
(1,4-dioxaspiro[4.5]dec-7-en-8-yl)vinyl]-4,4,5,5-tetramethyl-1,3,2-
dioxaborolane (61) is representative. To a solution of (Z)-[2-(1,4-
dioxaspiro[4,5]dec-7-en-8-yl)-vinyl]butyltelluride (42) (107 mg,
0.306 mmol) in anhydrous diethyl ether (5 mL) at ꢀ78 ꢁC under an
argon atmosphere was added n-butyllithium (0.220 mL, 1.53 M in
hexanes, 0.336 mmol) drop-wise. The reaction was stirred for
15 min before a solution of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-
dioxaborolane (0.121 mL, 0.612 mmol) was added drop-wise. The
reaction was stirred for a further 30 min at ꢀ78 ꢁC then allowed to
warm to rt over 2 h. After reaching rt the reaction mixture was
shielded from light, placed in an ice bath, and MeI (1.83 mmol,
0.114 mL) was added drop-wise after which the ice bath was re-
moved. After stirring for 30 min at rt the reaction mixture was di-
luted with diethyl ether and filtered through a plug of cotton using
suction filtration. The solvent was removed in vacuo and the
resulting crude oil was purified by silica column chromatography
(5:1, petroleum ether/diethyl ether) to yield the title compound
1619, 1495, 1255, 1141, 742, 692, 672.
3.27. (Z)-4,4,5,5-Tetramethyl-2-(4-methylstyryl)-1,3,2-
dioxaborolane (58)
The title compound was prepared as indicated in the repre-
sentative procedure. Purification by silica gel column chromatog-
raphy (20:1, petroleum ether/diethyl ether) yielded the title
compound (100 mg, 72%) as a colourless oil. 1H NMR (500 MHz)
d
ppm 1.28 (s, 12H), 2.32 (s, 3H), 5.50 (d, J¼14.9 Hz, 1H),43 7.09 (d,
J¼7.9 Hz, 2H), 7.16 (d, J¼14.9 Hz,1H), 7.43 (d, J¼8.1 Hz, 2H). 13C NMR
(125 MHz) 21.3, 24.8, 83.4, 128.6 (m), 135.6, 137.9, 148.2. IR n )
(cmꢀ1
2979, 2928, 2869, 1618, 1513, 1371, 1254, 1142, 836, 671. HRMS (ESI)
Calculated for C15H21BO2Naþ: 267.1533. Found: 267.1531.
3.28. (Z)-4,4,5,5-Tetramethyl-2-(4-(trifluoromethyl)styryl)-
1,3,2-dioxaborolane (59)
(64 mg, 72%) as a colourless oil. 1H NMR (300 MHz)
d ppm 1.26 (s,
12H), 1.78 (tt, J¼6.6, 0.8 Hz, 2H), 2.33–2.39 (m, 2H), 2.47–2.55 (m,
2H), 3.96 (s, 4H), 5.22 (dd, J¼14.9, 0.5 Hz, 1H), 5.71 (mc, 1H), 6.65 (d,
J¼15.1 Hz, 1H). 13C NMR (75 MHz) 24.8, 25.2, 30.9, 36.2, 64.4, 83.4,
107.8, 128.6, 137.4, 148.5. HRMS (ESI) Calculated for C16H25BO4Naþ:
The title compound was prepared as indicated in the represen-
tative procedure. Purification by silica gel column chromatography
(20:1, petroleum ether/diethyl ether) yielded the title compound
(167 mg, 70%) as white crystals, mp 58–60 ꢁC. 1H NMR (400 MHz)
315.1738. Found: 315.1745. IR n
(cmꢀ1) 2979, 2930, 2885,1634,1600,
d
ppm 1.27 (s, 12H), 5.71 (d, J¼14.9 Hz, 1H), 7.20 (d, J¼14.9 Hz, 1H),
7.52–7.56 (m, 2H), 7.60–7.64 (m, 2H). 13C NMR (100 MHz) 24.8, 83.7,
1255, 1142, 1111, 1059, 1045, 871, 692, 671.
1
3
124.2 (q, JCF¼272.2 Hz), 124.8 (q, JCF¼3.7 Hz), 128.8, 129.7 (q,
2JCF¼32.4 Hz), 141.8, 146.6. Anal. Calcd for C15H18F3BO2: C, 60.43; H,
3.24. (Z)-2-(3,4-Dimethoxystyryl)-4,4,5,5-tetramethyl-1,3,2-
dioxaborolane (55)
6.09. Found: C, 60.56; H, 6.25. IR
n
(cmꢀ1) 3051, 2986, 2933, 2871,
1616, 1574, 1319, 1260, 1163, 1136, 1110, 1065, 845, 670.
The title compound was prepared as indicated in the repre-
sentative procedure. Purification by silica gel column chroma-
tography (5:1, petroleum ether/diethyl ether) yielded the title
compound (72 mg, 65%) as white crystals, mp 49–51 ꢁC. 1H NMR
3.29. 1,4-Bis[(Z)-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-
2-yl)vinyl]benzene (60)
(400 MHz)
d
ppm 1.28 (s, 12H), 3.87 (s, 3H), 3.91 (s, 3H), 5.43 (d,
The title compound was prepared as indicated in the represen-
tative procedure. Purification by silica gel column chromatography
(15:1, petroleum ether/diethyl ether) yielded the title compound
(10 mg, 22%) as white needles, mp 122–126 ꢁC. 1H NMR (400 MHz)
J¼15.1 Hz, 1H), 6.78 (d, J¼8.3 Hz, 1H), 6.97–7.02 (m, 1H), 7.11 (d,
J¼15.1 Hz, 1H), 7.71 (d, J¼2.0 Hz, 1H). 13C NMR (100 MHz) 24.9,
55.8, 83.4, 110.3, 111.4, 123.3, 131.5, 148.5, 149.1, 149.2. HRMS (ESI)
Calculated for C16H23BO4Naþ: 313.1582. Found: 313.1572. Anal.
Calcd for C16H23BO4: C, 66.23; H, 7.99. Found: C, 66.20; H, 8.08. IR
d
ppm 1.28 (s, 24H), 5.56 (d, J¼14.9 Hz, 2H), 7.16 (d, J¼14.9 Hz, 2H),
7.50 (s, 4H). 13C NMR (100 MHz) 24.8, 83.5, 128.4, 138.1, 147.8. Anal.
Calcd for C22H32B2O4: C, 69.15; H, 8.44. Found: C, 68.89; H, 8.63. IR
n
(cmꢀ1) 3131, 3096, 2976, 2933, 2836, 1614, 1598, 1244, 1136,
1025, 876, 822, 673.
n
(cmꢀ1) 3093, 2980, 2934, 1613, 1513, 1446, 1248, 1136, 848, 670.

P.M. Mirzayans et al. / Tetrahedron 65 (2009) 8297–8305
8305
16. (a) Tucker, C. E.; Davidson, J.; Knochel, P. J. Org. Chem. 1992, 57, 3482; (b) Oh-
mura, T.; Yamamoto, Y.; Miyaura, N. J. Am. Chem. Soc. 2000, 122, 4990; (c) Hoshi,
M.; Shirakawa, K.; Okimoto, M. Tetrahedron Lett. 2007, 48, 8475; (d) Khramov,
D. M.; Rosen, E. L.; Er, J. A. V.; Vu, P. D.; Lynch, V. M.; Bielawski, C. W. Tetrahedron
2008, 64, 6853.
17. (a) Campbell, J. B., Jr.; Molander, G. A. J. Organomet. Chem. 1978, 156, 71; (b) Ne-
gishi, E.-i.; Williams, R. M.; Lew, G.; Yoshida, T. J. Organomet. Chem. 1975, 92, C4.
18. Matteson, D. S.; Majumdar, D. Organometallics 1983, 2, 230.
19. Kabalka, G. W.; Akula, M. R.; Zhang, J. Nucl. Med. Biol. 2003, 30, 369.
20. Lee, T.; Baik, C.; Jung, I.; Song, K. H.; Kim, S.; Kim, D.; Kang, S. O.; Ko, J. Organo-
metallics 2004, 23, 4569.
21. Barross, S. M.; Dabdoub, M. J.; Dabdoub, V. M. B.; Comasseto, J. V. Organome-
tallics 1989, 8, 1661.
22. (a) Huang, X.; Liang, C.; Qing, X.; He, Q. J. Org. Chem. 2001, 66, 74 and references
therein; (b) Zeni, G.; Lu¨dtke, D. S.; Panatieri, R. B.; Braga, A. L. Chem. Rev. 2006,106,
1032; (c) Petragnani, N.; Stefani, H. A. Tellurium in Organic Chemistry, Second,
Updated and Enlarged Edition; ACADEMIC PRESS: Amsterdam, Netherlands, 2007.
3.30. (Z)-2-(1-Cyclohexenylvinyl)-4,4,5,5-tetramethyl-1,3,2-
dioxaborolane (62)
The title compound was prepared as indicated in the repre-
sentative procedure. Purification by silica gel column chromatog-
raphy (30:1, petroleum ether/diethyl ether) yielded the title
compound (118 mg, 75%) as a colourless oil. 1H NMR (400 MHz)
d
ppm 1.26 (s, 12H), 1.53–1.66 (m, 4H), 2.07–2.15 (m, 2H), 2.21–2.27
(m, 2H), 5.15 (d, J¼14.9 Hz, 1H), 5.81 (mc, 1H), 6.62 (d, J¼14.9 Hz,
1H). 13C NMR (100 MHz) 22.1, 22.4, 24.8, 26.0, 26.3, 83.3, 132.1,
138.0, 149.8. IR
1141, 847, 671.
n
(cmꢀ1) 2979, 2929, 2860, 2833, 1629, 1599, 1255,
23.
A
preliminary communication describing the synthesis of cis-vinyl-
Supplementary data
trimethylstannes has been reported, see: Mirzayans, P. M.; Pouwer, R. H.;
Williams, C. M. Org. Lett. 2008, 10, 3861.
24. Stefani, H. A.; Costa, I. M.; Zeni, G. Tetrahedron Lett. 1999, 40, 9215.
25. Vieira, M. L.; Zinn, F. K.; Comasseto, J. V. J. Braz. Chem. Soc. 2001, 12, 586.
26. Huang, X.; Liang, C.-G. Synth. Commun. 2000, 30, 1903 and references therein.
When employing these methods one should also consider Refs. 14, 9 and 15.
27. Lenarda˜o, E. J.; Mendes, S. R.; Ferreira, P. C.; Perin, G.; Silveira, C. C.; Jacob, R. G.
Tetrahedron Lett. 2006, 47, 7439.
Supplementary data associated with this article can be found in
the online version, at doi:10.1016/j.tet.2009.06.092.
References and notes
28. Balfe, M. P.; Chaplin, C. A.; Phillips, H. J. Chem. Soc., Chem. Commun. 1938, 341.
29. Brown, H. C.; Cole, T. E. Organometallics 1983, 2, 1316.
30. Stefani, H. A.; Guadagnin, R. C.; Keppler, A. F.; Botteselle, G. V.; Comasseto, J. V.;
Suganuma, C. A. Beilstein J. Org. Chem. 2008, 4, No. 9.
31. (a) Stefani, H. A.; Cella, R.; Do¨rr, F. A.; Pereira, C. M. P.; Zeni, G.; Gomes, M., Jr.
Tetrahedron Lett. 2005, 46, 563; (b) Cella, R.; Orfa˜o, A. T. G.; Stefani, H. A. Tetra-
hedron Lett. 2006, 47, 5075; (c) Cella, R.; Stefani, H. A. Tetrahedron 2006, 62, 5656;
(d) Singh, F. V.; Weber, M.; Guadagnin, R. C.; Stefani, H. A. Synlett 2008, 1889.
32. Delmas, M.; Maire, J. C.; Santamaria, J. J. Organometal. Chem. 1969, 16, 405 and
references therein.
33. Nogueira, C. W.; Zeni, G.; Rocha, J. B. T. Chem. Rev. 2004, 104, 6255.
34. Gilman, H.; Beel, J. A.; Brannen, C. G.; Bullock, M. W.; Dunn, G. E.; Miller, L. S.
J. Am. Chem. Soc. 1949, 71, 1499.
1. See: Yu, T.-Q.; Fu, Y.; Liu, L.; Guo, Q. X. J. Org. Chem. 2006, 71, 6157 and refer-
ences therein.
2. (a) Branda¨nge, S.; Leijonmarck, H. Chem. Commun. 2004, 292 and references
therein; (b) Pouwer, R. H.; Schill, H.; Williams, C. M.; Bernhardt, P. V. Eur. J. Org.
Chem. 2007, 4699.
3. Stille, J. K. Angew. Chem., Int. Ed. Engl. 1986, 25, 508.
4. Miyaura, N.; Suzuki, A. Chem. Rev. 1995, 95, 2457.
5. For
a good comparative demonstration of both protocols, see: Lo´pez, S.;
Montenegro, J.; Saa´, C. J. Org. Chem. 2007, 72, 9572 and references therein.
6. Smith, N. D.; Mancuso, J.; Lautens, M. Chem. Rev. 2000, 100, 3257.
7. (a) Gevorgyan, V.; Liu, J. X.; Yamamoto, Y. Chem. Commun. 1998, 1, 37; (b) Asao,
N.; Liu, J. X.; Sudoh, T.; Yamamoto, Y. J. Org. Chem. 1996, 61, 4568; (c) Rim, C.;
Son, D. Y. Org. Lett. 2003, 5, 3443.
8. Kikukawa, K.; Umekawa, H.; Wada, F.; Matsuda, T. Chem. Lett. 1988, 881.
9. (a) Bickley, J. F.; Roberts, S. M.; Santoro, M. G.; Snape, T. J. Tetrahedron 2004, 60,
2569; (b) Bialy, L.; Waldmann, H. Chem.dEur. J. 2004, 10, 2759; (c) Lipshutz, B.;
Keil, R.; Barton, J. Tetrahedron Lett. 1992, 33, 5861.
35. This compound has previously been characterized, see: (a) Ref. 21; (b) Tucci, F.
C.; Chieffi, A.; Comasseto, J. V.; Marino, J. P. J. Org. Chem. 1996, 61, 4975.
36. This compound has previously been characterized, see: Dabdoub, M. J.; Dab-
doub, V. B.; Guerrero, P. G., Jr. Tetrahedron 1997, 53, 4199.
37. Hellwinkel, D.; Fahrbach, G. Chem. Ber. 1968, 101, 574.
38. For E-b-(trimethylstannyl)-3,4-dimethoxystyrene the alkene hydrogens give
10. Cochran, J. C.; Philips, H. K.; Tom, S.; Hurd, A. R.; Bronk, B. S. Organometallics
1994, 13, 947.
11. Thiele, C. M.; Mitchell, T. N. Eur. J. Org. Chem. 2004, 337.
J¼19.3 Hz at 6.71 and 6.84 ppm respectively. See: Koen, M. J.; Morgan, J.;
Pinhey, J. T.; Sherry, C. J. J. Chem. Soc., Perkin Trans. 1 1997, 487.
39. This compound has previously been characterized, see: Ref. 10.
40. For E-b-(trimethylstannyl)-4-methylstyrene the alkene hydrogens give a sin-
12. Miura, K.; Wang, D.; Matsumoto, Y.; Hosomi, A. Org. Lett. 2005, 7, 503.
13. Srebnik, M.; Bhat, N. G.; Brown, H. C. Tetrahedron Lett. 1988, 29, 2635.
14. (a) Soderquist, J. A.; Rane, A. M.; Matos, K.; Ramos, J. Tetrahedron Lett. 1995, 36,
6847; (b) Molander, G. A.; Ellis, N. M. J. Org. Chem. 2008, 73, 6841.
15. (a) Deloux, L.; Srebnik, M. J. Org. Chem. 1994, 59, 6871; (b) Pereira, S.; Srebnik,
M. Organometallics 1995, 14, 3127; (c) Deloux, L.; Skrzypczak-Jankun, E.;
Cheesman, B. V.; Srebnik, M. J. Am. Chem. Soc. 1994, 116, 10302; (d) Deloux, L.;
Srebnik, M.; Sabat, M. J. Org. Chem. 1995, 60, 3276.
glet at 6.86 ppm 2H, see: Ref. 38.
41. Due to overlap of reference signal with [MꢀMe]þ.
42. This compound has previously been characterized, see: Ref. 14b.
43. For (E)-4,4,5,5-tetramethyl-2-(4-methylstyryl)-1,3,2-dioxaborolane the alkene hy-
drogens give J¼18.0 Hz at 6.10 and 7.36 ppm respectively. See: Itami, K.; Tonogaki,
K.; Nokami, T.; Ohashi, Y.; Yoshida, J. Angew. Chem., Int. Ed. 2006, 45, 2404.