Regioselective 1,4-silylcupration of 1,3-dienes - Characterization and electrophilic trapping of the intermediate σ-allyl)copper complex

Article abstract of DOI:10.1002/1099-0690(200211)2002:21<3527::AID-EJOC3527>3.0.CO;2-H

Silylcupration reactions of 1,3-dienes with a cyanocuprate reagent PhMe₂SiCuCNLi produce a (4-silyl-2-alken-1-yl)-copper complex, which was trapped by electrophiles. The use of allylic phosphates as electrophiles resulted in highly regioselecti

Full text of DOI:10.1002/1099-0690(200211)2002:21<3527::AID-EJOC3527>3.0.CO;2-H

FULL PAPER
Regioselective 1,4-Silylcupration of 1,3-Dienes ؊ Characterization and
Electrophilic Trapping of the Intermediate (σ-Allyl)copper Complex
Vilnis Liepins[a] and Jan-E. Bäckvall*[a]
Keywords: Copper / Dienes / Allylic compounds
Silylcupration reactions of 1,3-dienes with a cyanocuprate re-
agent PhMe2SiCuCNLi produce (4-silyl-2-alken-1-yl)-
regioselective 1,2-addition. The intermediate (4-silyl-2-
alken-1-yl)copper complexes were characterized by NMR
spectroscopy. The mechanism of the silylcupration reaction
of 1,3-dienes and subsequent electrophilic trapping is discus-
sed.
a
copper complex, which was trapped by electrophiles. The
use of allylic phosphates as electrophiles resulted in highly
regioselective reactions with overall 1,4-addition of the silyl
and allyl moieties across the diene. Water (H3O+) or acetyl
chloride as the electrophile afforded a mixture of 1,2- and
1,4-addition products, whereas carbon dioxide gave a highly
( Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany,
2002)
Introduction
Results and Discussion
Most of the silylcupration reactions previously studied
were carried out with the silylcuprate reagent
(PhMe2Si)2CuLi·LiCN (1) or more bulky silylcuprate
reagents.[2d] Recently, the cyanocuprate reagent PhMe2-
SiCuCNLi[13] (2) was used by Pulido[14] and ourselves[3] in
allene silylcupration reactions. We also employed this re-
agent in the silylcupration reaction of styrenes[11] and
acetylenes.[4] The advantage of the silylcopper reagent
PhMe2SiCuCNLi over the disilyl cuprate reagent
(PhMe2Si)2CuLi·LiCN is that all the silyl species in the re-
agent are used in the reaction. With the latter reagent only
one of the two silyl groups is transferred and the remaining
silylcopper reagent leads to side products upon reaction
with the electrophile employed. These side-products are
formed in equimolar amounts with the desired product, and
are difficult to separate from it. Therefore we focussed on
the use of the monosilylcopper reagent PhMe2SiCuCNLi in
the silylcupration reaction of 1,3-dienes.
The silylcupration reaction of acetylenes and allenes has
been studied by Fleming and co-workers,[1,2] and by our-
selves.[3,4] However, literature data on silyl-metallations of
alkenes are scarce. Silylcupration of a double bond in oxab-
icyclic compounds has been reported.[5] Silylmanganation
of acetylenes and 1,3-dienes,[6] silyltitanation[7] of 1,3-di-
enes, and catalytic silicon-silicon bond addition across
double bonds,[8] triple bonds[9] and 1,3-dienes[10] involving
silylpalladation have also been reported. Recently, we re-
ported on a silylcupration reaction of styrene[11] and a tan-
dem silylcupration-electrophilic trapping reaction of 1,3-di-
enes.[12] To the best of our knowledge, there are no other
publications in the literature on silylcupration of dienes. At
the time of our preliminary communication it was not clear
whether the regioisomers arise from a mixture of isomeric
(σ-allyl)copper complexes (1,2- and 1,4-isomers) or from
one (σ-allyl)copper complex (1,2- or 1,4-isomer) via SE2
and SE2Ј cleavage reactions. We have now characterized the
(σ-allyl)copper intermediate and found it to be only one
regioisomer, namely a [(Z)-4-silyl-2-alken-1-yl]copper com-
plex obtained from an overall 1,4-silylcupration across the
1,3-diene system. The mechanism and silylcupration of 1,3-
dienes and subsequent electrophilic trapping is discussed.
The silylcupration of 1,3-dienes with
2 proceeded
smoothly at temperatures ranging from Ϫ78 °C to 0 °C.
The organocopper intermediates thus obtained were effici-
ently trapped by different electrophiles, including allylic
phosphates,[15] which are viable and readily accessible allylic
substrates for metal-catalyzed reactions.[3,11,12,15a,16] Previ-
ously we successfully used allylic phosphates as reactive al-
lylic electrophiles in the silylcupration reaction of allenes,[3]
styrenes,[11] and acetylenes.[4]
[a]
Department of Organic Chemistry, Arrhenius Laboratory,
Stockholm University,
10691 Stockholm, Sweden
Fax: (internat.) ϩ 46-8/154-908
The regioselectivity of the trapping reaction of the copper
intermediate obtained from the silylcupration of the diene
depends strongly on the electrophile. With carbon dioxide
E-mail: jeb@organ.su.se
Supporting information for this article is available on the
WWW under http://www.eurjoc.org or from the author.
Eur. J. Org. Chem. 2002, 3527Ϫ3535  2002 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim 1434Ϫ193X/02/1121Ϫ3527 $ 20.00ϩ.50/0
3527

V. Liepins, J.-E. Bäckvall
FULL PAPER
as electrophile, the 1,2-addition product was formed exclus- Mechanism, Scope and Limitations
ively (Scheme 1, Table 1).
The regioselectivity of the tandem silylcupration-elec-
trophilic trapping reaction is interesting from both a syn-
thetic and a mechanistic point of view. A priori a mixture
of 1,2- and 1,4-silylcopper intermediates, 33 and 34 respect-
ively, can form in the silylcupration step of the diene
(Scheme 4, see Table 2). The electrophilic cleavage may oc-
cur in an SE2 and/or SE2Ј fashion depending on the elec-
trophile.
Scheme 1
In order to obtain information concerning the ratio of (σ-
allyl)copper intermediates 33 and 34 formed in the reaction,
attempts to characterize the silylcupration adduct were
made. Silylcupration of 1,3-butadiene by PhMe2SiCuCNLi
Table 1. Silylcupration of 1,3-dienes followed by reaction with CO2
as electrophile
1
in [D8]THF was monitored by H NMR spectroscopy at 0
°C. After 10 min, complete conversion into the silylcupr-
ation adduct had occurred and only the 1,4-addition prod-
uct 34a was observed, as indicated by the appearance of
two new doublets for CH2Cu (J ϭ 9.3 Hz) and CH2Si (J ϭ
7.7 Hz) at δ ϭ 0.83 ppm and 1.56 ppm, respectively. The
corresponding reactions of isoprene (4) and 2,3-dimethyl-
1,3-butadiene (5) with PhMe2SiCuCNLi in [D8]THF
showed that only 1,4-silylcupration to give 34b and 34c, re-
spectively, had occurred also for these dienes according to
1H NMR spectroscopy. From the NMR spectra we con-
clude that there is only 1,4-addition and the 1,2-adduct was
not observed.
The spectra of the silylcupration products 34a, 34b, and
34c from dienes 3, 4, and 5, respectively, did not change
when left at 0 °C for 30 min, indicating either that the 1,4-
adduct is the thermodynamically stable (σ-allyl)copper spe-
[a]
Isolated yields.
With water (H3Oϩ) and acetyl chloride as electrophiles, cies or that there is no equilibrium between the 1,4- and 1,2-
mixtures of 1,2- and 1,4-addition products were obtained adduct. In the case of 1,3-butadiene NOESY experiments
(Scheme 2, Table 2). The ratio of 1,2- and 1,4-addition indicate that the 1,4-silylcupration adduct 34a is of Z-ste-
products was found to be independent of the reaction tem- reochemistry, and this stereochemical assignment was sup-
perature. Thus, silylcupration of isoprene at temperatures ported by a JH,H coupling of 10 Hz between the olefin pro-
ranging from Ϫ78 °C to 0 °C followed by quenching with tons.
a proton source afforded an 85:15 mixture of the 1,2- and
1,4-addition products in all cases (Table 2, entries 2Ϫ4).
It has been recently proposed that silylcupration of styr-
enes and acetylenes proceeds via a mechanism involving nu-
However, with allylic phosphates, allylic phosphinates or cleophilic attack by the silylcopper reagent 2 at the terminal
MeI as quenching electrophiles only the 1,4-adducts were carbon of the double and triple bonds respectively.[4,11]
A
formed (Scheme 3, Table 3), except for two cases where a similar mechanism has been proposed for the carbocupr-
mixture of 1,2- and 1,4-adducts was obtained (Table 3, ent- ation of acetylenes.[20] With an analogous mechanism for
ries 5, 7). Unfortunately, allylic phosphates from 3,3-disub- 1,3-dienes, attack by copper at the terminal carbon of the
stituted allylic alcohols were unstable and decomposed diene would give intermediate 35, with the indicated cis
upon purification.[17] Therefore, allylic phosphinates[18] configuration. It is known that crotyl anions are more
were used as a more stable, but still highly reactive,[19] al- stable in the cis form than in the trans form.[21,22] Reductive
ternative. Allylic phosphinate 19 was prepared from 3,3-di- elimination and trapping of the anion by copper() would
methyl allyl alcohol, and proved to be sufficiently reactive give 34a and this mechanism explains the Z-stereochem-
to give the desired 1,5-diene product (Table 3, entry 8).
istry (Scheme 5).
Scheme 2
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Eur. J. Org. Chem. 2002, 3527Ϫ3535

Regioselective 1,4-Silylcupration of 1,3-Dienes
FULL PAPER
Table 2. Silylcupration of 1,3-dienes followed by reaction with H3Oϩ or AcCl as electrophile
[a]
[b]
With water as electrophile a saturated aqueous NH4Cl solution was used. Isolated yields.
Scheme 5
Scheme 3
Scheme 4
Eur. J. Org. Chem. 2002, 3527Ϫ3535
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V. Liepins, J.-E. Bäckvall
FULL PAPER
Table 3. Selective 1,4-Silylcupration-electrophilic trapping reaction of 1,3-dienes
[a]
Isolated yields.
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Eur. J. Org. Chem. 2002, 3527Ϫ3535

Regioselective 1,4-Silylcupration of 1,3-Dienes
FULL PAPER
The selectivity of the electrophilic trapping step is very
When mixtures of 1,2- and 1,4-products are obtained,
dependent on the electrophile employed, and the elec- both mechanisms (oxidative addition/reductive elimination
trophilic cleavage can occur in either an SE2 or an SE2Ј and SE2Ј electrophilic cleavage) are likely to operate. Altern-
manner (Scheme 6).
atively the 1,4-product may be formed via a classical SE2
cleavage and this is a likely pathway for the protonolysis
(three-center mechanism).
In two particular cases the reaction of the silylcuprated
diene with allylic phosphates gave a mixture of 1,4- and 1,2-
addition products. Allylic phosphates can react in the α-
or γ-position. The regioselectivity for the 1,4-γ- and 1,2-α-
product is surprisingly high; no 1,4-α- or 1,2-γ-product was
observed. Thus, as can be seen from Table 3 (entries 5 and
7) the 1,4-product is a result of a selective γ-substitution
reaction of the allylic phosphate, whereas the 1,2-product
gives only the α-substituted allylic chain. It is proposed that
the initial product of these reactions, similar to all other
reactions involving allylic phosphates as electrophiles, is the
CuIII intermediate 37 formed by γ-selective oxidative addi-
tion.[28] In this case the formation of 1,2-α-product via a
cyclic transition state (3,3Ј-coupling) would compete with
the normal reductive elimination (1,1Ј-coupling) due to
steric hindrance in the latter pathway (Scheme 9).
Scheme 6. Electrophilic trapping step of the copper intermediate
Carbon dioxide reacts exclusively via an SE2Ј pathway,
whereas allylic phosphates give mainly SE2 reaction prod-
ucts. A similar selectivity was observed by Normant in the
electrophilic trapping of an allylcopper intermediate re-
sulting from addition of tBuCu to 1,3-butadiene.[23] How-
ever, no mechanistic discussion or explanation was given.
We believe that the reaction leading to the 1,4-product is
not a normal SE2 cleavage but that it occurs in two steps:
first the allylic phosphate oxidatively adds to copper in in-
termediate 34 to give a copper() intermediate[20] (36).
Subsequent reductive elimination then gives the observed
product (Scheme 7). The same two-step mechanism via ox-
idative addition would also apply to allylic phosphinates
and MeI. We have recently obtained experimental evidence
that the reaction between allylic esters and diallyl cuprates
Another explanation for the formation of the 1,2-α-prod-
uct would be the [3,3]-sigmatropic rearrangement of the ini-
tially formed 1,4-γ-product. However, when compound 24a
(1,4-γ-product) was heated for one hour at 280 °C, no re-
arranged product was detected and only starting material
could be recovered. A control experiment was carried out
to see whether copper can catalyze this Cope rearrangement
under the reaction conditions. Thus, compound 24a was ad-
ded to a silylcupration-electrophilic trapping reaction mix-
ture, but no rearranged product 24b could be detected. A
[3,3]-sigmatropic rearrangement of an initially formed 1,4-
γ-product to the 1,2-α-product can therefore be ruled out.
proceeds via CuIII [24]
.
In the case of selective γ-cleavage by CO2 the mechanism
most likely involves a classical SE2Ј electrophilic cleavage
(Scheme 8). Many allylmetal species, such as allylbor-
anes,[25] allyltin[26] and allylsilanes,[27] are known to react
with electrophiles in an SE2Ј manner.
As can be seen from the data above, only 1,3-dienes with
unsubstituted terminal carbons are used, as, unfortunately,
Scheme 7. Allylic substitution mechanism
Scheme 8. A plausible mechanism of a γ-selective electrophilic trapping by CO2
Eur. J. Org. Chem. 2002, 3527Ϫ3535
3531

V. Liepins, J.-E. Bäckvall
FULL PAPER
Scheme 9
able even by HPLC. The stereochemistry of the products was con-
firmed by NOE or NOESY experiments.
cyclic and terminally substituted 1,3-dienes are not reactive
enough in this reaction. A similar observation has been re-
ported in the carbocupration reaction of 1,3-dienes.[23]
Thus, under standard silylcupration reaction conditions
used for silylcupration of dienes 3, 4, 5 and 6 neither 1,3-
pentadiene nor 1,3-cyclohexadiene gave any reaction prod-
uct. The diene was left intact under these conditions. Upon
addition of electron-releasing ligands such as PPh3 or
PnBu3 to the reaction mixture, however, small amounts of
the desired products could be isolated. Unfortunately, the
yields of these reactions could not be brought up to useful
levels. In the case of 1,3-cyclohexadiene we isolated 6% of
the product, whereas 1,3-pentadiene gave 34% isolated yield
of the addition-protonolysis product.
Unless otherwise noted, all materials were obtained from commer-
cial suppliers and used without further purification. Allylic phos-
phates,[15] phosphinates[18] and PhMe2SiLi[13a] were prepared ac-
cording to published procedures. Elemental analysis was performed
by Analytische Laboratorien, Lindlar, Germany. Tetrahydrofuran
(THF) and diethyl ether (Et2O) were freshly distilled from sodium
benzophenone ketyl under an argon atmosphere prior to use. All
reactions were performed under an argon atmosphere using flame-
dried glassware.
General Procedure for Silylcupration of 1,3-Dienes Followed by Elec-
trophilic Trapping with Water or Acetyl Chloride: PhMe2SiLi
(0.7 mmol, ഠ1  solution in THF) was added to a stirred suspen-
sion of CuCN (0.7 mmol, 1 equiv.) in dry THF (0.7 mL) at 0 °C
and stirred at this temperature for 20 min. The mixture was then
cooled to the temperature indicated in Table 1 and the diene
(1.05 mmol, 1.5 equiv.) was added dropwise (butadiene was added
from a cylinder in excess). After stirring for 0.5 h at this temper-
ature the reaction mixture was quenched with saturated aqueous
NH4Cl (4 mL) and the aqueous phase was extracted with pentane
(5 ϫ 3 mL). If acetyl chloride was used as electrophile, 1.5 equiv.
of it was added dropwise to the reaction mixture (instead of NH4Cl
aq.) and the reaction mixture was stirred at the same temperature
for 1 h followed by quenching with saturated aqueous NH4Cl (4
mL) and extraction as indicated before. Evaporation of the solvent
and subsequent column chromatography on silica with pentane
(pentane/diethyl ether in the case of acetates) as eluent afforded the
products indicated in Table 1 as colorless oils.
Conclusion
An efficient 1,4-silylcupration reaction of terminal 1,3-
dienes followed by electrophilic trapping with various elec-
trophiles has been developed. This method provides an easy
access to substituted 1,5-diene systems containing the silyl
group, which are useful intermediates in organic synthesis.
Mechanistic studies indicate a highly selective 1,4-silylcupr-
ation step leading to (σ-allyl)copper complexes which were
characterized by NMR spectroscopy. Different electrophiles
used in the trapping reaction of the copper intermediate can
give different regiochemistry, i.e. SE2 or SE2Ј substitution
products. This method broadens the scope of the silylcupr-
ation reaction and gives an insight into the mechanism of
the reaction.
General Procedure for Silylcupration of 1,3-Dienes Followed by Elec-
trophilic Trapping with Carbon Dioxide: PhMe2SiLi (1.0 mmol, ഠ1
 solution in THF) was added to a stirred suspension of CuCN
(1.0 mmol, 1 equiv.) in dry THF (1 mL) at 0 °C. After stirring at
this temperature for 20 min the mixture was cooled to Ϫ30 °C and
the diene (1.5 mmol, 1.5 equiv.) was added dropwise (butadiene was
added from a cylinder in excess). The reaction mixture was stirred
for 0.5 h at this temperature, and then CO2 gas was passed through
the reaction mixture for about 10 min. The reaction mixture was
quenched with 4 mL of aqueous 1  HCl solution followed by
extraction with diethyl ether. After evaporation of the solvent, col-
umn chromatography on silica with pentane/ethyl acetate as eluent
afforded the products indicated in Table 2 as colorless oils.
Experimental Section
General: 1H NMR (400 or 300 MHz) and 13C NMR (100 or
75 MHz) spectra were recorded on Varian Mercury spectrometers
using the residual solvent peak in CDCl3 (δ ϭ 7.26 ppm for 1H
1
and δ ϭ 77.17 ppm for 13C) or in [D8]THF (δ ϭ 3.58 ppm for H)
as internal standard; chemical shifts are reported in ppm. Millipore
˚
Matrex 60 A (35Ϫ70 µm) silica gel was used for flash chromato-
graphy. TLC analysis was performed on Merck 60 F254 precoated
plates. Some isomeric products were separated using AgNO3/silica
gel column chromatography technique,[29] since they were insepar-
General Procedure for Silylcupration of 1,3-Dienes Followed by Elec-
trophilic Trapping with Allylic Phosphates, Phosphinates or MeI:
PhMe2SiLi (0.7 mmol, ഠ1  solution in THF) was added to a
3532
Eur. J. Org. Chem. 2002, 3527Ϫ3535

Regioselective 1,4-Silylcupration of 1,3-Dienes
FULL PAPER
stirred suspension of CuCN (0.7 mmol, 1 equiv.) in dry THF (0.7
mL) at 0 °C. After stirring at this temperature for 20 min the reac-
tion mixture was cooled to Ϫ40 °C and the diene (1.05 mmol, 1.5
(m, 1 H), 4.75 (s, 1 H), 4.69 (s, 1 H), 2.03 (m, 6 H), 1.68 (s, 3 H),
1.59 (s, 3 H), 0.89 (ddd, J ϭ 8.1, 5.0, 4.0 Hz, 2 H), 0.28 (s, 6 H)
ppm. 13C NMR (CDCl3 100 MHz): δ ϭ 152.3, 139.4, 133.7, 131.7,
equiv.) was added dropwise (butadiene was added from a cylinder 129.0, 127.9, 124.4, 107.8, 36.0, 30.4, 26.6, 25.8, 17.8, 14.0, Ϫ3.0
in excess). The reaction mixture was stirred for 0.5 h at this temper-
ature and then the temperature was lowered to Ϫ78 °C and allylic
phosphate or allylic phosphinate (1.2 equiv.) in 0.6 mL THF was
added slowly over 30 min with a syringe pump. After the reaction
mixture had been stirred for 1 h at Ϫ78 °C, 4 mL of saturated
aqueous NH4Cl was added and the aqueous phase was extracted
with pentane (5 ϫ 3 mL).
ppm.
[(2E)-3,7-Dimethyl-2,6-octadienyl]dimethyl(phenyl)silane (12b): Al-
though this compound is known, only the 13C NMR spectrum has
been reported,[35] therefore we give the H NMR spectrum of this
1
compound here. Mol. wt. ϭ 272.50; yield ϭ 78 mg, 41% (mixture
of 12a and 12b). H NMR (CDCl3 400 MHz): δ ϭ 7.51 (m, 2 H),
7.35 (m, 3 H), 5.17 (tq, J ϭ 8.5, 1.2 Hz, 1 H), 5.09 (tt, J ϭ 6.7,
1.3 Hz, 1 H), 2.02 (m, 4 H), 1.68 (s, 3 H), 1.64 (d, J ϭ 8.5 Hz, 2
H), 1.60 (s, 3 H), 1.49 (s, 3 H), 0.26 (s, 6 H) ppm.
1
When MeI was used in the electrophilic trapping step, 3 equiv. of it
was added to the silylcupration mixture at Ϫ40 °C, and the reaction
mixture was stirred at this temperature for 1 h. The workup proced-
ure was identical to that described above. Evaporation of the solv-
ent and subsequent column chromatography on silica with pentane
as eluent afforded the products indicated in Table 3 as colorless oils.
(2Z)-2,6-Heptadienyldimethyl(phenyl)silane [(Z)-20]: Mol. wt. ϭ
230.42; yield ϭ 116 mg, 72% (mixture of (Z)-20 and (E)-20). 1H
NMR (CDCl3 400 MHz): δ ϭ 7.56 (m, 2 H), 7.39 (m, 3 H), 5.83
(m, 1 H), 5.45 (m, 1 H), 5.32 (m, 1 H), 5.03 (ddt, J ϭ 17.1, 2.1,
0.9 Hz, 1 H), 4.98 (ddt, J ϭ 10.1, 2.1, 1.0 Hz, 1 H), 2.07 (m, 4 H),
1.76 (dd, J ϭ 8.5, 1.3 Hz, 2 H), 0.33 (s, 6 H) ppm. 13C NMR
(CDCl3 100 MHz): δ ϭ 138.9, 133.8, 129.23, 129.15, 129.11, 128.0,
127.7, 114.7, 34.0, 26.8, 17.9, Ϫ3.01 ppm.
The identity of some products was proven by comparison with pub-
lished spectroscopic data: 8a,[30] 8b,[31] 9a,[32] 9b,[33] 10a[2c], 11a[33]
11b[2c], 27.[34]
,
2-[(Dimethylphenylsilyl)methyl]-3-butenoic Acid (7a): Mol. wt. ϭ
1
234.37; yield ϭ 192 mg, 82%. H NMR (300 MHz): δ ϭ 9.44 (br. (2E)-2,6-Heptadienyldimethyl(phenyl)silane [(E)-20]: Mol. wt. ϭ
s, 1 H), 7.51 (m, 2 H), 7.36 (m, 3 H), 5.81 (ddd, J ϭ 17.0, 10.0, 230.42; yield ϭ 116 mg, 72% [mixture of (Z)-20 and (E)-20]. 1H
8.5 Hz, 1 H), 5.12 (dt, J ϭ 17.0, 1.2 Hz, 1 H), 5.10 (dt, J ϭ 10.0, NMR (CDCl3 400 MHz): δ ϭ 7.56 (m, 2 H), 7.39 (m, 3 H), 5.83
1.2 Hz, 1 H), 3.11 (app. q, J ϭ 8.5 Hz, 1 H), 1.36 (dd, J ϭ 14.8,
7.1 Hz, 1 H), 1.12 (dd, J ϭ 14.8, 8.5 Hz, 1 H), 0.33 (s, 3 H), 0.32
(m, 1 H), 5.45 (m, 1 H), 5.32 (m, 1 H), 5.03 (ddt, J ϭ 17.1, 2.1,
0.9 Hz, 1 H), 4.98 (ddt, J ϭ 10.1, 2.1, 1.0 Hz, 1 H), 2.11 (m, 4 H),
(s, 3 H) ppm. 13C NMR (75.4 MHz): δ ϭ 181.4, 138.4, 137.6, 133.8, 1.70 (dq, J ϭ 7.7, 0.9 Hz, 2 H), 0.31 (s, 6 H) ppm. 13C NMR
129.3, 128.0, 117.0, 46.0, 19.1, Ϫ2.2, Ϫ2.5 ppm. MS (EI): m/z
(%) ϭ 219 (30), 175 (78), 137 (73), 135 (100), 113 (28), 97 (35), 127.7, 114.7, 34.4, 32.5, 21.9, Ϫ3.14 ppm. C15H22Si [mixture of (Z)-
75 (29). 20 and (E)-20]: calcd. C 78.19, H 9.62; found C 77.92, H 9.46.
(CDCl3 100 MHz): δ ϭ 139.1, 133.9, 129.2, 129.15, 129.11, 127.9,
2-[(Dimethylphenylsilyl)methyl]-3-methyl-3-butenoic Acid (7b): Mol. Dimethyl[(2Z)-3-methyl-2,6-heptadienyl]phenylsilane (21): Mol.
1
wt. ϭ 248.39; yield ϭ 189 mg, 76%. 1H NMR (300 MHz): δ ϭ
10.16 (br. s, 1 H), 7.51 (m, 2 H), 7.36 (m, 3 H), 4.91 (m, 1 H), 4.89
wt. ϭ 244.45; yield ϭ 123 mg, 72%. H NMR (CDCl3 400 MHz):
δ ϭ 7.54 (m, 2 H), 7.38 (m, 3 H), 5.82 (m, 1 H), 5.21 (app. t, J ϭ
(quintet, J ϭ 1.5 Hz, 1 H), 3.15 (app. t, J ϭ 7.5 Hz, 1 H), 1.74 (dd, 8.3 Hz, 1 H), 5.02 (dq, J ϭ 17.1, 1.5 Hz, 1 H), 4.95 (ddt, J ϭ 10.2,
J ϭ 1.5, 1.0 Hz, 3 H), 1.41 (dd, J ϭ 14.9, 8.2 Hz, 1 H), 1.12 (dd, 2.1, 1.0 Hz, 1 H), 2.06 (m, 4 H), 1.71 (app. q, J ϭ 1.2 Hz, 3 H),
J ϭ 14.9, 7.2 Hz, 1 H), 0.32 (s, 6 H) ppm. 13C NMR (75.4 MHz): 1.68 (dq, J ϭ 8.3, 1.1 Hz, 2 H), 0.30 (s, 6 H) ppm. 13C NMR
δ ϭ 180.8, 144.0, 138.4, 133.8, 129.2, 127.9, 114.2, 48.8, 19.8, 17.1, (CDCl3 100 MHz): δ ϭ 139.3, 139.1, 133.7, 133.1, 129.0, 127.8,
Ϫ2.66, Ϫ2.71 ppm. MS (EI): m/z (%) ϭ 189 (45), 157 (29), 137
120.2, 114.3, 32.2, 31.1, 23.5, 17.6, Ϫ3.0 ppm. C16H24Si: calcd. C
(36), 135 (100), 111 (34), 75 (28), 73 (52).
78.62, H 9.90; found C 78.46, H 9.83.
2-[(Dimethylphenylsilyl)methyl]-2,3-dimethyl-3-butenoic Acid (7c):
Mol. wt. ϭ 262.42; yield ϭ 192 mg, 73%. 1H NMR (300 MHz):
δ ϭ 11.13 (br. s, 1 H), 7.53 (m, 2 H), 7.35 (m, 3 H), 4.98 (m, 1 H),
[(2Z)-3,6-Dimethyl-2,6-heptadienyl]dimethyl(phenyl)silane
(22):
Mol. wt. ϭ 258.47; yield ϭ 128 mg, 71%. 1H NMR (CDCl3
400 MHz): δ ϭ 7.54 (m, 2 H), 7.38 (m, 3 H), 5.20 (t, J ϭ 8.5 Hz,
4.92 (dt, J ϭ 2.5, 1.3 Hz, 1 H), 1.77 (d, J ϭ 1.4 Hz, 3 H), 1.55 (d, 1 H), 4.71 (s, 1 H), 4.69 (s, 1 H), 2.10 (m, 2 H), 2.00 (m, 2 H), 1.75
J ϭ 14.6 Hz, 1 H), 1.35 (d, J ϭ 14.6 Hz, 1 H), 1.32 (s, 3 H), 0.36 (s, 3 H), 1.72 (m, 3 H), 1.68 (d, J ϭ 8.5 Hz, 2 H), 0.31 (s, 6 H)
(s, 3 H), 0.34 (s, 3 H) ppm. 13C NMR (75.4 MHz): δ ϭ 183.3, ppm. 13C NMR (CDCl3 75.4 MHz): δ ϭ 146.4, 139.3, 133.8, 133.6,
148.1, 139.8, 133.7, 129.0, 127.9, 111.7, 50.1, 25.1, 24.1, 20.2, Ϫ1.3, 129.0, 127.8, 120.0, 109.6, 36.0, 30.2, 23.5, 22.7, 17.6, Ϫ3.0 ppm.
Ϫ1.4 ppm. MS (EI): m/z (%) ϭ 203 (19), 171 (27), 137 (23), 135 C17H26Si: calcd. C 79.00, H 10.14; found C 79.02, H 10.05.
(100), 125 (57), 75 (24), 73 (18).
Dimethyl[(2Z,6E)-3-methyl-2,6-octadienyl]phenylsilane
[(E)-23]:
(Z)-6-(Dimethylphenylsilyl)-4-methyl-4-hexen-2-one (10b): Mol.
wt. ϭ 246.42; yield ϭ 129 mg, 75% (mixture of 10a and 10b). H
Mol. wt. ϭ 258.47; yield ϭ 123 mg, 68% [mixture of (Z)-23 and
(E)-23]. H NMR (CDCl3 400 MHz): δ ϭ 7.56 (m, 2 H), 7.39 (m,
1
1
NMR (CDCl3 300 MHz): δ ϭ 7.51 (m, 2 H), 7.37 (m, 3 H), 5.41
3 H), 5.45 (m, 2 H), 5.21 (m, 1 H), 2.05 (m, 2 H), 2.01 (s, 3 H),
(tq, J ϭ 8.3, 1.1 Hz, 1 H), 2.97 (s, 2 H), 2.05 (s, 3 H), 1.71 (q, J ϭ 1.75Ϫ1.63 (m, 7 H), 0.299 (s, 6 H) ppm. 13C NMR (CDCl3
1.1 Hz, 3 H), 1.66 (d, J ϭ 8.3 Hz, 2 H), 0.29 (s, 6 H) ppm. 13C 100 MHz): δ ϭ 139.42, 133.74, 131.56, 130.64, 129.02, 127.84,
NMR (CDCl3 75 MHz): δ ϭ 207.3, 138.7, 133.7, 129.2, 127.9, 124.77, 119.97, 31.81, 31.01, 23.53, 18.08, 17.50, Ϫ3.02.
126.9, 124.3, 47.2, 29.2, 24.2, 18.3, Ϫ3.1 ppm. MS (EI): m/z (%) ϭ
Dimethyl[(2Z,6Z)-3-methyl-2,6-octadienyl]phenylsilane
[(Z)-23]:
231 (8), 153 (7), 137 (23), 136 (14), 135 (100), 107 (7), 75 (46).
Mol. wt. ϭ 258.47; yield ϭ 123 mg, 68% [mixture of (Z)-23 and
1
Dimethyl(7-methyl-3-methylene-6-octenyl)phenylsilane (12a): Mol.
wt. ϭ 272.50; yield ϭ 78 mg, 41% (mixture of 12a and 12b). 1H
NMR (CDCl3 400 MHz): δ ϭ 7.51 (m, 2 H), 7.35 (m, 3 H), 5.10
(E)-23]. H NMR (CDCl3 400 MHz): δ ϭ 7.56 (m, 2 H), 7.39 (m,
3 H), 5.45 (m, 2 H), 5.21 (m, 1 H), 2.05 (m, 2 H), 2.01 (s, 3 H),
1.75Ϫ1.63 (m, 7 H), 0.302 (s, 6 H) ppm. 13C NMR (CDCl3
Eur. J. Org. Chem. 2002, 3527Ϫ3535
3533

V. Liepins, J.-E. Bäckvall
100 MHz): δ ϭ 139.42, 133.49, 131.56, 130.64, 129.02, 127.84, 128.8, 127.8, 125.9, 111.0, 43.7, 40.2, 20.3, 18.2, 18.1, Ϫ1.9, Ϫ2.6
FULL PAPER
123.94, 120.11, 31.51, 25.35, 23.46, 17.56, 12.90, Ϫ3.02 ppm.
C17H26Si [mixture of (E)-23 and (Z)-23]: calcd. C 79.00, H 10.14;
found C 78.91, H 9.99.
ppm.
Dimethyl[(Z)-3-methyl-2-pentenyl]phenylsilane (28): Mol. wt. ϭ
218.41; yield ϭ 105 mg, 69%. 1H NMR (CDCl3 400 MHz): δ ϭ
7.52 (m, 2 H), 7.35 (m, 3 H), 5.12 (tq, J ϭ 8.3, 1.2 Hz, 1 H), 1.97
(q, J ϭ 7.5 Hz, 2 H), 1.70 (app. q, J ϭ 1.2 Hz, 3 H), 1.67 (dq, J ϭ
8.3, 1.2 Hz, 2 H), 0.92 (t, J ϭ 7.5 Hz, 3 H), 0.29 (s, 6 H) ppm. 13C
NMR (CDCl3 100 MHz): δ ϭ 139.5, 135.4, 133.8, 129.0, 127.8,
118.9, 24.5, 23.0, 17.4, 12.5, Ϫ3.1 ppm. C14H22Si: calcd. C 76.99,
H 10.15; found C 76.60, H 9.99.
Dimethyl[(2Z)-3-methyl-5-propyl-2,6-heptadienyl]phenylsilane (24a):
Mol. wt. ϭ 286.53; yield ϭ 142 mg, 71% (mixture of 24a and 24b).
1H NMR (CDCl3 400 MHz): δ ϭ 7.52 (m, 2 H), 7.36 (m, 3 H),
5.54 (m, 1 H), 5.21 (t, J ϭ 8.1 Hz, 1 H), 4.92 (ddd, J ϭ 17.0, 2.0,
0.8 Hz, 1 H), 4.91 (dd, J ϭ 10.3, 2.0 Hz, 1 H), 2.15 (m, 1 H), 1.98
(dd, J ϭ 13.5, 6.7 Hz, 1 H), 1.92 (dd, J ϭ 13.5, 8.2 Hz, 1 H), 1.66
(s, 3 H), 1.64 (d, J ϭ 8.1 Hz, 2 H), 1.24 (m, 4 H), 0.87 (t, J ϭ
7.0 Hz, 3 H), 0.27 (s, 6 H) ppm. 13C NMR (CDCl3 100 MHz): δ ϭ
143.4, 139.5, 133.8, 132.4, 129.0, 127.8, 121.0, 113.7, 42.2, 37.5,
36.8, 24.0, 20.5, 17.6, 14.3, Ϫ3.0 ppm. C19H30Si (mixture of 24a
and 24b): calcd. C 79.65, H 10.55; found C 79.46, H 10.36.
(5Z)-5,6,8-Trimethyl-8-phenyl-1,5-nonadiene [(Z)-29]: Mol. wt. ϭ
258.47; yield ϭ 103 mg, 57% [mixture of (Z)-29 and (E)-29]. 1H
NMR (CDCl3 300 MHz): δ ϭ 7.52 (m, 2 H), 7.35 (m, 3 H), 5.79
(ddt, J ϭ 17.0, 10.3, 6.3 Hz, 1 H), 4.97 (dq, J ϭ 17.0, 1.6 Hz, 1 H),
4.91 (ddt, J ϭ 10.3, 2.1, 1.1 Hz, 1 H), 2.00 (m, 4 H), 1.78 (s, 2 H),
1.62 (s, 3 H), 1.56 (s, 3 H), 0.29 (s, 6 H) ppm. 13C NMR (CDCl3
75 MHz): δ ϭ 140.0, 139.3, 133.7, 129.0, 127.8, 125.29, 125.26,
114.1, 34.3, 32.4, 24.7, 21.5, 18.1, Ϫ2.1 ppm. MS (EI): m/z (%) ϭ
217 (21), 181 (5), 161 (11), 137 (6), 136 (15), 135 (100), 107 (4).
[(E)-2-Isopropenyl-4-octenyl]dimethyl(phenyl)silane (24b): Mol.
1
wt. ϭ 286.53; yield ϭ 142 mg, 71% (mixture of 24a and 24b). H
NMR (CDCl3 300 MHz): δ ϭ 7.50 (m, 2 H), 7.34 (m, 3 H), 5.32
(dt, J ϭ 15.4, 6.2 Hz, 1 H), 5.25 (dt, J ϭ 15.4, 6.5 Hz, 1 H), 4.65
(m, 2 H), 2.24 (m, 1 H), 2.00 (m, 2 H), 1.93 (app. q, J ϭ 7.1 Hz, 2
H), 1.57 (t, J ϭ 1.1 Hz, 3 H), 1.34 (sextet, J ϭ 7.3 Hz, 2 H), 0.92
(d, J ϭ 6.0 Hz, 1 H), 0.90 (d, J ϭ 8.6 Hz, 1 H), 0.87 (t, J ϭ 7.3 Hz,
3 H), 0.29 (s, 3 H), 0.27 (s, 3 H) ppm. 13C NMR (CDCl3 75 MHz):
δ ϭ 149.2, 140.1, 133.7, 133.5, 128.9, 128.8, 127.8, 111.0, 43.8, 40.3,
34.8, 22.9, 20.3, 18.3, 13.8, Ϫ1.9, Ϫ2.5 ppm.
(5E)-5,6,8-Trimethyl-8-phenyl-1,5-nonadiene [(E)-29]: Mol. wt. ϭ
258.47; yield ϭ 103 mg, 57% [mixture of (Z)-29 and (E)-29]. 1H
NMR (CDCl3 300 MHz): δ ϭ 7.52 (m, 2 H), 7.35 (m, 3 H), 5.82
(m, 1 H), 5.02 (dm, J ϭ 17.1 Hz, 1 H), 4.94 (dm, J ϭ 10.1 Hz, 1
H), 2.09 (m, 4 H), 1.76 (s, 2 H), 1.56 (m, 3 H), 1.51 (m, 3 H), 0.30
(s, 6 H) ppm. 13C NMR (CDCl3 75 MHz): δ ϭ 140.0, 139.3, 133.7,
129.0, 127.8, 125.7, 125.5, 114.3, 34.3, 32.9, 25.2, 20.9, 19.1, Ϫ2.1
ppm. MS (EI): m/z (%) ϭ 217 (19), 181 (4), 161 (10), 137 (7), 136
(13), 135 (100), 107 (4).
Dimethyl[(2Z,6E)-3-methyl-2,6-decadienyl]phenylsilane
[(E)-25]:
Mol. wt. ϭ 286.53; yield ϭ 106 mg, 53% [mixture of (Z)-25 and
1
(E)-25]. H NMR (CDCl3 400 MHz): δ ϭ 7.54 (m, 2 H), 7.37 (m,
3 H), 5.41 (m, 2 H), 5.18 (t, J ϭ 8.4 Hz, 1 H), 2.01 (m, 4 H), 1.97
(m, 2 H), 1.69 (s, 3 H), 1.66 (d, J ϭ 8.4 Hz, 2 H), 1.39 (q, J ϭ
7.2 Hz, 2 H), 0.91 (t, J ϭ 7.2 Hz, 3 H), 0.29 (s, 6 H) ppm. 13C
NMR (CDCl3 100 MHz): δ ϭ 139.44, 133.75, 133.53, 130.45,
130.32, 129.0, 127.84, 119.94, 34.86, 31.89, 31.05, 23.56, 22.86,
17.52, 13.83, Ϫ3.01 ppm.
{(2E)-3-[(3-Butenyl)]-7-methyl-2,6-octadienyl}dimethyl(phenyl)silane
(30): Mol. wt. ϭ 312.56; yield ϭ 116 mg, 53%. H NMR (CDCl3
1
400 MHz): δ ϭ 7.54 (m, 2 H), 7.37 (m, 3 H), 5.82 (m, 1 H), 5.21
(app. t, J ϭ 8.3 Hz, 1 H), 5.12 (t pent., J ϭ 6.8, 1.5 Hz, 1 H), 5.01
(ddt, J ϭ 17.0, 2.1, 1.5 Hz, 1 H), 4.95 (ddt, J ϭ 10.1, 2.1, 1.0 Hz,
1 H), 2.05 (m, 8 H), 1.71 (s, 3 H), 1.69 (d, J ϭ 8.3 Hz, 2 H), 1.63
(s, 3 H), 0.30 (s, 6 H) ppm. 13C NMR (CDCl3 100 MHz): δ ϭ
139.3, 139.1, 136.9, 133.8, 131.4, 129.0, 127.8, 124.8, 120.3, 114.3,
37.0, 32.4, 29.2, 27.2, 25.9, 17.9, 17.6, Ϫ3.1 ppm. C21H32Si: calcd.
C 80.70, H 10.32; found C 80.40, H 10.08.
Dimethyl[(2Z,6Z)-3-methyl-2,6-decadienyl]phenylsilane
[(Z)-25]:
Mol. wt. ϭ 286.53; yield ϭ 106 mg, 53% [mixture of (Z)-25 and
1
(E)-25]. H NMR (CDCl3 400 MHz): δ ϭ 7.51 (m, 2 H), 7.35 (m,
3 H), 5.35 (app. t., J ϭ 4.5 Hz, 2 H), 5.16 (t, J ϭ 8.5 Hz, 1 H),
2.01 (m, 6 H), 1.69 (s, 3 H), 1.65 (d, J ϭ 8.5 Hz, 2 H), 1.37 (q, J ϭ
7.6 Hz, 2 H), 0.90 (t, J ϭ 7.6 Hz, 3 H), 0.26 (s, 6 H) ppm. 13C
NMR (CDCl3 100 MHz): δ ϭ 139.40, 133.75, 133.52, 129.97,
129.86, 129.03, 127.83, 120.09, 31.82, 29.46, 25.74, 23.50, 23.05,
17.58, 13.97, Ϫ3.03 ppm.
Dimethyl{(2E)-7-methyl-3-[(E)-3-pentenyl]-2,6-octadienyl}phenyl-
silane [(E)-31]: Mol. wt. ϭ 326.59; yield ϭ 160 mg, 70% (mixture
1
of (Z)-31 and (E)-31). H NMR (CDCl3 400 MHz): δ ϭ 7.52 (m,
2 H), 7.35 (m, 3 H), 5.41 (m, 2 H), 5.17 (m, 1 H), 5.10 (m, 1 H),
2.02 (m, 6 H), 1.98 (s, 3 H), 1.70Ϫ1.56 (m, 10 H), 0.272 (s, 6 H)
ppm. 13C NMR (CDCl3 100 MHz): δ ϭ 139.42, 137.25, 133.77,
131.61, 131.33, 130.68, 129.03, 127.83, 124.77, 120.07, 37.09, 31.29,
29.89, 27.22, 25.90, 18.08, 17.87, 17.54, Ϫ3.11.
[(2Z)-3,5-Dimethyl-2,6-heptadienyl]dimethyl(phenyl)silane
(26a):
Mol. wt. ϭ 258.47; yield ϭ 100 mg, 55% (mixture of 26a and 26b).
1H NMR (CDCl3 400 MHz): δ ϭ 7.52 (m, 2 H), 7.36 (m, 3 H),
5.74 (ddd, J ϭ 17.3, 10.4, 7.0 Hz, 1 H), 5.22 (t, J ϭ 8.1 Hz, 1 H),
4.95 (dt, J ϭ 17.3, 1.6 Hz, 1 H), 4.88 (ddd, J ϭ 10.4, 1.7, 1.1 Hz,
1 H), 2.31 (m, 1 H), 1.94 (d, J ϭ 7.1 Hz, 1 H), 1.93 (d, J ϭ 7.8 Hz,
1 H), 1.66 (s, 3 H), 1.64 (d, J ϭ 8.9 Hz, 2 H), 0.93 (d, J ϭ 6.8 Hz,
3 H), 0.26 (s, 6 H) ppm. 13C NMR (CDCl3 100 MHz): δ ϭ 144.8,
139.4, 133.7, 132.3, 129.0, 127.8, 121.2, 112.1, 38.7, 35.9, 23.9, 19.6,
17.6, Ϫ3.01, Ϫ3.02 ppm.
Dimethyl{(2E)-7-methyl-3-[(Z)-3-pentenyl]-2,6-octadienyl}phenyl-
silane [(Z)-31]: Mol. wt. ϭ 326.59; yield ϭ 160 mg, 70% (mixture
1
of (Z)-31 and (E)-31). H NMR (CDCl3 400 MHz): δ ϭ 7.52 (m,
2 H), 7.35 (m, 3 H), 5.41 (m, 2 H), 5.17 (m, 1 H), 5.10 (m, 1 H),
2.02 (m, 6 H), 1.98 (s, 3 H), 1.70Ϫ1.56 (m, 10 H), 0.275 (s, 6 H)
ppm. 13C NMR (CDCl3 100 MHz): δ ϭ 139.42, 137.25, 133.77,
131.61, 131.33, 130.68, 129.03, 127.83, 124.82, 120.21, 37.05, 31.29,
29.58, 27.27, 25.66, 18.08, 17.61, 12.91, Ϫ3.11 ppm. C22H34Si (mix-
ture of (E)-31 and (Z)-31): calcd. C 80.91, H 10.49; found C 81.05,
H 10.47.
[(E)-2-Isopropenyl-4-hexenyl]dimethyl(phenyl)silane (26b): Mol.
1
wt. ϭ 258.47; yield ϭ 100 mg, 55% (mixture of 26a and 26b). H
NMR (CDCl3 400 MHz): δ ϭ 7.51 (m, 2 H), 7.35 (m, 3 H), 5.34
(m, 1 H), 5.27 (m, 1 H), 4.65 (m, 2 H), 2.24 (m, 1 H), 1.99 (m, 2
H), 1.62 (dq, J ϭ 6.0, 1.4 Hz, 3 H), 1.57 (s, 3 H), 0.90 (d, J ϭ [(2E)-3-Ethyl-7-methyl-2,6-octadienyl]dimethyl(phenyl)silane (32):
6.0 Hz, 1 H), 0.89 (d, J ϭ 8.7 Hz, 1 H), 0.29 (s, 3 H), 0.27 (s, 3 H)
Mol. wt. ϭ 286.53; yield ϭ 134 mg, 67%. 1H NMR (CDCl3
ppm. 13C NMR (CDCl3 100 MHz): δ ϭ 149.2, 140.1, 133.7, 129.9, 400 MHz): δ ϭ 7.52 (m, 2 H), 7.35 (m, 3 H), 5.10 (m, 2 H), 2.01
3534
Eur. J. Org. Chem. 2002, 3527Ϫ3535

Regioselective 1,4-Silylcupration of 1,3-Dienes
FULL PAPER
I. Fleming, R. S. Roberts, S. C. Smith, J.
[13b]
1994; 12, 257.
(m, 4 H), 1.94 (q, J ϭ 7.5 Hz, 2 H), 1.68 (s, 3 H), 1.65 (d, J ϭ
8.5 Hz, 2 H), 1.60 (s, 3 H), 0.89 (t, J ϭ 7.5 Hz, 3 H), 0.26 (s, 6 H)
ppm. 13C NMR (CDCl3 100 MHz): δ ϭ 139.5, 139.2, 133.8, 131.3,
129.0, 127.8, 124.9, 119.1, 36.6, 27.2, 25.9, 22.6, 17.9, 17.4, 12.8,
Ϫ3.1 ppm. C19H30Si: calcd. C 79.65, H 10.55; found C 79.61, H
10.38.
Chem. Soc., Perkin Trans. 1 1998, 1209Ϫ1214.
[14] [14a]
F. J. Blanco, P. Cuadrado, A. M. Gonzalez, F. J. Pulido, I.
[14b]
Fleming, Tetrahedron Lett. 1994, 35, 8881Ϫ8882.
A.
Barbero, C. Garcia, F. J. Pulido, Tetrahedron Lett. 1999, 40,
[14c]
6649Ϫ6652.
A. Barbero, C. Garcia, F. J. Pulido, Tetrahed-
ron 2000, 56, 2739Ϫ2751.
[15] [15a]
H. Yamamoto, N. Nomura, A. Yanagisawa, Tetrahedron
1994, 50, 6017Ϫ6028. [15b] P. Knochel, C. Jubert, E. C. Tucker,
S. Nowotny, J. Org. Chem. 1995, 60, 2762Ϫ2772.
Allylic phosphates have previously been used as electrophiles
in a copper-catalysed cross coupling reaction with Grignard
{(Z)-4-[Dimethyl(phenyl)silyl]-2-butenyl}copper (34a): 1H NMR
([D8]THF 400 MHz): δ ϭ 7.49 (m, 2 H), 7.25 (m, 3 H), 5.71 (dt,
J ϭ 10.0, 9.3 Hz, 1 H), 4.33 (dt, J ϭ 10.0, 7.7 Hz, 1 H), 1.56 (d,
J ϭ 7.7 Hz, 2 H), 0.83 (d, J ϭ 9.3 Hz, 2 H), 0.19 (s, 6 H) ppm.
[16]
[16a]
reagents:
A. Yanagisawa, Y. Noritake, N. Nomura, H. Ya-
[16b]
mamoto, Synlett 1991, 251Ϫ253.
A. Yanagisawa, N. No-
mura, H. Yamamoto, Synlett 1993, 689Ϫ690.
[17] [17a]
Acknowledgments
Financial support from the Swedish Research Council and The
Swedish Foundation for Strategic Research is gratefully acknow-
ledged.
J. A. Miller, H. C. S. Wood, Angew. Chem. 1964, 76, 301;
[17b]
Angew. Chem. Int. Ed. Engl. 1964, 3, 310.
K. Yasui, K.
Fugami, S. Tanaka, Y. Tamaru, J. Org. Chem. 1995, 60,
1365Ϫ1380.
[18]
[19]
J. S. McCallum, L. S. Liebeskind, Synthesis 1993, 819Ϫ823.
We previously demonstrated that allylic acetates are not react-
ive enough as electrophiles in the trapping reaction of vinylcop-
per species; see ref.[3]
For a thorough discussion see: E. Nakamura, S. Mori, Angew.
Chem. 2000, 112, 3902Ϫ3924; Angew. Chem. Int. Ed. 2000,
39, 3750Ϫ3771.
[1] [1a]
I. Fleming, F. Roessler, J. Chem. Soc., Chem. Commun.
[1b]
1980, 276Ϫ277.
Chem. Soc., Perkin Trans. 1 1981, 2527Ϫ2532.
E. Martinez de Marigorta, J. Chem. Soc., Perkin Trans. 1 1999,
889Ϫ900.
I. Fleming, T. W. Newton, F. Roessler, J.
[20]
[1c]
I. Fleming,
[1d]
A. Barbero, F. J. Pulido, Recent Res. Dev. Synth.
[21] [21a]
P. v. R. Schleyer, J. Kaneti, Y. D. Wu, J. Chandrasekhar, J.
Org. Chem. 1999, 2, 1Ϫ22.
Organomet. Chem. 1992, 426, 143Ϫ157. [21b] R. B. Bates, W. A.
Beavers, J. Am. Chem. Soc. 1974, 96, 5001Ϫ5002.
It is also possible that the cis-configuration of the product 34a
arises from a reductive elimination of a plausible CuIII metal-
lacycle:
[2] [2a]
I. Fleming, F. J. Pulido, J. Chem. Soc., Chem. Commun.
[2b]
1986, 1010Ϫ1011.
ido, I. Fleming, Tetrahedron Lett. 1988, 29, 1825Ϫ1826.
P. Cuadrado, A. M. Gonzalez, F. J. Pul-
[22]
[2c]
P.
Cuadrado, A. M. Gonzalez-Nogal, F. J. Pulido, I. Fleming, M.
Rowley, Tetrahedron 1989, 45, 413Ϫ424. [2d] A. Barbero, P. Cu-
adrado, A. M. Gonzalez, F. J. Pulido, I. Fleming, J. Chem.
Soc., Perkin Trans. 1 1991, 2811Ϫ2816. [2e] I. Fleming, Y. Lan-
dais, P. R. Raithby, J. Chem. Soc., Perkin Trans. 1 1991,
715Ϫ719.
[3]
[4]
[5]
[23]
[24]
[25]
V. Liepins, A. S. E. Karlström, J. E. Bäckvall, Org. Lett. 2000,
2, 1237Ϫ1239.
J. Normant, G. Cahiez, J. Villieras, J. Organomet. Chem. 1975,
92, C28ϪC30.
V. Liepins, A. S. E. Karlström, J. E. Bäckvall, J. Org. Chem.
2002, 67, 2136Ϫ2143.
A. S. E. Karlström, J. E. Bäckvall, Chem. Eur. J. 2001, 7,
1981Ϫ1989.
M. Lautens, R. K. Belter, A. J. Lough, J. Org. Chem. 1992,
G. W. Kramer, H. C. Brown, J. Org. Chem. 1977, 42,
57, 422Ϫ424.
2292Ϫ2299.
[6] [6a]
[26] [26a]
K. Fugami, S. Nakatsukasa, K. Oshima, K. Utimoto, H.
J. A. Marshall, K. W. Hinkle, J. Org. Chem. 1996, 61,
[26b]
Nozaki, Chem. Lett. 1986, 6, 869Ϫ870. [6b] K. Fugami, K. Osh-
ima, K. Utimoto, H. Nozaki, Tetrahedron Lett. 1986, 27,
2161Ϫ2164. [6c] K. Fugami, J. Hibino, S. Nakatsukasa, S. Mat-
subara, K. Oshima, K. Utimoto, H. Nozaki, Tetrahedron 1988,
44, 4277Ϫ4292.
105Ϫ108.
A. Hosomi, H. Iguchi, M. Endo, H. Sakurai,
Chem. Lett. 1979, 8, 977Ϫ980.
[27]
T. H. Chan, I. Fleming, Synthesis 1979, 10, 761Ϫ786.
[28] [28a]
´
J. E. Bäckvall, M. Sellen, B. Grant, J. Am. Chem. Soc.
[28b]
1990, 112, 6615Ϫ6621.
Org. Chem. 1984, 49, 422Ϫ426.
H. L. Goering, S. S. Kantner, J.
[7]
[8]
[28c]
K. Tamao, M. Akita, R. Kanatani, N. Ishida, M. Kumada, J.
Organomet. Chem. 1982, 226, C9ϪC13.
T. Hayashi, T. Kobayashi, A. M. Kawamoto, H. Yamashita,
M. Tanaka, Organometallics 1990, 9, 280Ϫ281.
E. J. Corey, N. W. Boaz,
Tetrahedron Lett. 1985, 26, 6015Ϫ6018.
C. M. Williams, L. N. Mander, Tetrahedron 2001, 57, 425Ϫ447.
I. Fleming, N. J. Lawrence, J. Chem. Soc., Perkin Trans. 1 1992,
24, 3309Ϫ3326.
[29]
[30]
[9] [9a]
H. Watanabe, M. Kobayashi, M. Saito, Y. Nagai, J. Or-
[31]
[32]
ganomet. Chem. 1981, 216, 149Ϫ157. [9b] J. Hibino, S. Nakatsu-
kasa, K. Fugami, S. Matsubara, K. Oshima, H. Nozaki, J. Am.
Chem. Soc. 1985, 107, 6416Ϫ6417.
R. J. Smith, M. Pietzsch, T. Waniek, C. Syldatk, S. Bienz, Tet-
rahedron: Asymmetry 2001, 12, 157Ϫ165.
K. Takaki, T. Kusudo, S. Uebori, T. Nishiyama, T. Kamata,
M. Yokoyama, K. Takehira, Y. Makioka, Y. Fujiwara, J. Org.
Chem. 1998, 63, 4299Ϫ4304.
[10] [10a]
K. Tamao, S. Okazaki, M. Kumada, J. Organomet. Chem.
[10b]
1978, 146, 87Ϫ93.
H. Matsumoto, K. Shono, A. Wada, I.
[33]
[34]
[35]
Matsubara, H. Watanabe, Y. Nagai, J. Organomet. Chem. 1980,
J. Tang, H. Shinokubo, K. Oshima, Bull. Chem. Soc. Jpn. 1997,
[10c]
199, 185Ϫ193.
H. Sakurai, Y. Eriyama, Y. Kamiyama, Y.
70, 245Ϫ251.
[10d]
Nakadaira, J. Organomet. Chem. 1984, 264, 229Ϫ237.
W. Carlson, R. West, Organometallics 1983, 2, 1801Ϫ1807.
V. Liepins, J. E. Bäckvall, Chem. Commun. 2001, 265Ϫ266.
V. Liepins, J. E. Bäckvall, Org. Lett. 2001, 3, 1861Ϫ1864.
C.
I. Ojima, M. Kumagai, J. Organomet. Chem. 1978, 157,
359Ϫ372.
Y. Tsuji, M. Funato, M. Ozawa, H. Ogiyama, S. Kajita, T. Ka-
wamura, J. Org. Chem. 1996, 61, 5779Ϫ5787.
Received June 13, 2002
[11]
[12]
[13] [13a] I. Fleming, in Organocopper reagents. A practical approach
(Ed.: R. J. K. Taylor), Oxford University press: New York,
[O02318]
Eur. J. Org. Chem. 2002, 3527Ϫ3535
3535