Pd-catalyzed sulfinylzincation of activated alkynes with 1-alkynyl sulfoxides as a sulfinyl source

Article abstract of DOI:10.1021/jo034108j

Unprecedented Pd-catalyzed sulfinylzincation with 1-alkynyl sulfoxide as a sulfinyl source was developed. Bis-sulfinyl alkenes were formed in good yields on treatment of 1-alkynyl sulfoxides with Et₂Zn in the presence of a Pd-catalyst, wherein

Full text of DOI:10.1021/jo034108j

P d -Ca ta lyzed Su lfin ylzin ca tion of Activa ted Alk yn es w ith
1-Alk yn yl Su lfoxid es a s a Su lfin yl Sou r ce
Naoyoshi Maezaki, Suguru Yagi, Ryoko Yoshigami, J un Maeda, Tomoko Suzuki,
Shizuka Ohsawa, Kouji Tsukamoto, and Tetsuaki Tanaka*
Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita,
Osaka 565-0871, J apan
t-tanaka@phs.osaka-u.ac.jp
Received J anuary 28, 2003
Unprecedented Pd-catalyzed sulfinylzincation with 1-alkynyl sulfoxide as a sulfinyl source was
developed. Bis-sulfinyl alkenes were formed in good yields on treatment of 1-alkynyl sulfoxides
with Et2Zn in the presence of a Pd-catalyst, wherein zinc sulfenate (or sulfinylzinc) species would
be generated in situ to undergo highly syn-selective conjugate addition to the 1-alkynyl sulfoxides.
By using 3,3-dimethyl-1-butynyl sulfoxides, formation of the bis-sulfinyl alkenes was completely
suppressed and the sulfinylzincation of activated alkynes was accomplished. The reaction tolerates
various functionalities, and was promoted considerably by the neighboring group participation of
the heteroatom at the δ-position in the alkynoates. Stereodivergent synthesis of two diastereomeric
vinylic sulfoxides and reaction of the resulting vinylzinc species with electrophiles were also
described.
SCHEME 1
In tr od u ction
The chemistry of sulfenic acids has been extensively
investigated to demonstrate the existence of the species
as intermediates in biological processes, or to develop a
convenient method for the synthesis of vinylic sulfoxides
via addition to an unsaturated bond.1 The species have
also received considerable attention, since asymmetric
addition of this species affords a novel method to syn-
thesize versatile chiral vinylic sulfoxides by employing
sulfenic acids with a chiral auxiliary.2 Recent progress
in this area is making this unstable species a useful tool
in synthetic organic chemistry.
In contrast to the evolution of sulfenic acid chemistry,
little attention has been paid to the use of the corre-
sponding conjugate bases, sulfenate anions, for organic
synthesis. This sulfenate anion is an ambident nucleo-
phile bearing two nucleophilic sites at the sulfur and
oxygen atoms, and presumably exists as an equilibrium
between the sulfenate anion and the sulfinyl anion as
shown in Scheme 1. The character of this species is not
well-known so far, since they are very unstable for
oxidation to sulfinates and self-condensation to thiosul-
finates. There are few reports regarding sodium sulfenates,
which are generated in situ from stable precursors, such
as sulfenyl esters, sulfenyl halides, disulfides, and 2-sul-
finylpyridine N-oxides, using strong alkaline conditions.3
Furukawa and co-workers have, for the first time,
isolated sodium sulfenates and proved the existence of
the species.4 However, reactions of the corresponding zinc
salts have not hitherto been reported, to the best of our
knowledge, although reactions of organozinc reagents are
known to show high selectivity and tolerance to a variety
of functionalities.5
Previously, we have accomplished Pd-catalyzed sulfin-
ylzincation of activated alkynes using 1-alkynyl sulfox-
ides as a sulfinyl source, in which a zinc sulfenate species
was suggested as a reaction intermediate (Scheme 1).6
The zinc sulfenate species underwent addition to acti-
vated alkynes such as 1-alkynyl sulfoxides and alkynoates
(3) Hogg, D. R.; Stewart, J . J . Chem. Soc., Perkin Trans. 2 1974,
43-47. Danehy, J . P.; Parameswaran, K. N. J . Org. Chem. 1968, 33,
568-572.
(4) Furukawa, N.; Konno, Y.; Tsuruoka, M.; Fujihara, H.; Ogawa,
S. Chem. Lett. 1989, 1501-1504.
(5) For selected reviews, see: Boudier, A.; Bromm, L. O.; Lotz, M.;
Knochel, P. Angew. Chem., Int. Ed. 2000, 39, 4414-4435. Nakamura,
M.; Nakamura, E. J . Synth. Org. Chem. J pn. 1998, 56, 632-644.
Knochel, P. Synlett 1995, 393-403.
(6) Maezaki, N.; Yoshigami, R.; Maeda, J .; Tanaka, T. Org. Lett.
2001, 3, 3627-3629.
(1) Review: (a) Hogg, D. R. In The Chemistry of Sulfenic Acids and
Their Derivatives; Patai, S., Ed.; J ohn Wiley & Sons: Chichester, UK,
1990; pp 361-402. (b) Van den Breok, L. A. G. M.; Delbressine, L. P.
C.; Ottenheijm, H. C. J . In The Chemistry of Sulfenic Acids and Their
Derivatives; Patai, S., Ed.; J ohn Wiley & Sons: Chichester, UK, 1990;
pp 701-721.
(2) Aversa, M. C.; Barattucci, A.; Bonaccorsi, P.; Giannetto, P.;
Policicchio, M. J . Org. Chem. 2001, 66, 4845-4851.
10.1021/jo034108j CCC: $25.00 © 2003 American Chemical Society
Published on Web 06/17/2003
5550
J . Org. Chem. 2003, 68, 5550-5558

Pd-Catalyzed Sulfinylzincation
SCHEME 2
SCHEME 3
TABLE 1. Effect of P d -Ca ta lyst on Su lfin ylzin ca tion a
As a result, we found that the yield of 2a was signifi-
cantly affected by a ligand of the Pd-catalyst (Table 1).
The yield was improved with replacement of the ligand
from dppf to dppe, MeCN, or PPh3 (entries 1-4). Pd(0)-
catalysts [Pd(PPh3)4 and Pd2(dba)3‚CHCl3] yielded the bis-
sulfinyl alkene 2a in excellent yields (entries 5 and 6).
Especially, the use of Pd2(dba)3‚CHCl3 afforded the best
results, and the yield improved up to 95%8 (entry 6). In
each case, only 2 mol % of catalyst was sufficient to
complete the reaction. Although the reaction provided 2a
even without a catalyst, longer reaction time was re-
quired for completion of the reaction, and both yield and
selectivity were reduced (entry 7). Later, the reaction was
found to proceed via a different reaction mechanism.
The reaction took place even in less polar toluene (70%)
or more polar dioxane (69%) with Pd2(dba)3‚CHCl3. The
yield of 2a was almost unchanged over a range of
concentrations (0.1-0.01 M) (81-95%), but was lowered
by decreasing the amount of Pd2(dba)3‚CHCl3 [1 mol %
(69%), 0.5 mol % (62%)] or Et2Zn [1 equiv (61%)].
Sulfinylzincation with 1a provided a 1:1 mixture of two
isomers, even though the optically pure 1a was used.9
Since oxidation of 2a with m-CPBA afforded a single bis-
sulfonyl alkene (E)-4, these two compounds were con-
firmed not to be geometric isomers, but to be diastereo-
meric isomers arising from two sulfur stereogenic centers.
The geometry of the double bond in 2a was determined
by comparing NOE between the olefinic proton and the
allylic proton in (E)-4 with that of the (Z)-isomer prepared
via conjugated addition of TolSH to 1a and subsequent
oxidation to the bis-sulfonyl alkene. It should be noted
that two geometric isomers could be synthesized stereo-
divergently in excellent yields and with high stereose-
lectivity by using two protocols (Scheme 3).
yield (%)c
entry
Pd-catalystb
time (h)
2a d
3a
1
2
3
4
5
6
7
PdCl2(dppf)
PdCl2(dppe)
PdCl2(MeCN)2
PdCl2(PPh3)2
Pd(PPh3)4
1
1
1
1
1
1
4
44
73
86
82
88
95
56
19
7
trace
4
trace
trace
29
Pd2(dba)3‚CHCl3
none
a
All reactions were carried out with Et2Zn (2 equiv) in THF
b
(0.1 M) solution at -78 °C to room temperature. 2 mol % of
catalyst was used. c Isolated yield. The yield is based on 50% of
d
1a and the diastereomeric ratio is 1:1. dppf ) 1,1′-bis(diphenyl-
phosphino)ferrocene, dppe ) 1,2-bis(diphenylphosphino)ethane.
at the sulfur atom rather than at the oxygen to give
vinylic sulfoxides with high syn-selectivity under mild
conditions. The resulting â-sulfinyl R,â-unsaturated es-
ters are potentially useful building blocks with several
reactive sites.7
Herein, we will describe full details of the sulfinylzin-
cation. We found that a heteroatom at the δ-position of
alkynoates exhibits a neighboring effect and two Michael
acceptors in a molecule were differentiated utilizing this
effect. Influence of the reagent structure on the reactivity,
stereodivergent synthesis of two geometric vinylic sul-
foxides, and reaction of the resulting vinylzinc intermedi-
ate with electrophiles were also investigated.
Resu lts a n d Discu ssion
Syn th esis of Bis-su lfin yl Alk en es by P d -Ca ta lyzed
Su lfin ylzin ca tion . During the course of our research
regarding the reaction of 1-alkynyl sulfoxides and an
organozinc reagent, we unexpectedly found that 1-hex-
ynyl p-tolyl sulfoxide 1a underwent an unusual sulfin-
ylation on treatment with Et2Zn in the presence of
catalytic PdCl2(dppf) (Scheme 2, entry 1 in Table 1). Bis-
sulfinyl alkene 2a was obtained in 44% yield as a 1:1
diastereomeric mixture based on sulfur stereogenic cen-
ters accompanied by a (Z)-isomer of ethylation product
3a (19%). Both reactions proceeded in a highly syn-
selective fashion, giving 2a and 3a exclusively.
Table 2 shows the sulfinylzincation of various 1-alkynyl
sulfoxides 1b-f.10 Functional groups such as TBS, Ac,
and I are compatible in this reaction (entries 1-3). The
nucleophile-sensitive acetyl group was not affected under
the reaction conditions and no iodine-zinc exchange
reaction was observed.11 However, the reaction of methyl
propiolate 1e (R ) H) was sluggish and a 2:1 (E/ Z)-
(8) Yields of the bis-sulfinyl alkenes were calculated based on the
theoretical maximum 50% yield in this paper.
(9) The diastereomeric isomers were presumably produced by ra-
cemization of the introduced sulfoxide via sulfinyl-sulfenate tautomer-
ization (see Scheme 1). However, it is possible to introduce optically
pure sulfoxide by using an epimeric mixture of sulfoxide bearing a
chiral auxiliary. We have already reported the preliminary results of
the asymmetric sulfinylzincation in a recent report. Maezaki, N.; Yagi,
S.; Ohsawa, S.; Ohishi, H.; Tanaka, T. Tetrahedron: Asymmetry 2002,
13, 1961-1964.
We were interested in the unexpected product 2a and
investigated the reaction conditions to optimize the yield.
(7) For leading references for reaction of vinylic sulfoxides, see:
Mase, N.; Watanabe, Y.; Toru, T.; Kakumoto, T.; Hagiwara, T. J . Org.
Chem. 2000, 65, 7083-7090. Maezaki, N.; Izumi, M.; Yuyama, S.;
Sawamoto, H.; Iwata, C.; Tanaka, T. Tetrahedron 2000, 56, 7927-
7945. Abe, H.; Tsuchida, D.; Kashino, S.; Takeuchi, Y.; Harayama, T.
Chem. Pharm. Bull. 1999, 47, 833-837. Midura, W. H.; Krysiak, J .
A.; Mikolajczyk, M. Tetrahedron 1999, 55, 14791-14802. Priego, J .;
Carretero, J . C. Synlett 1999, 1603-1605. Buezo, N. D.; Alonso, I.;
Carretero, J . C. J . Am. Chem. Soc. 1998, 120, 7129-7130.
(10) Kosugi, H.; Kitaoka, M.; Tagami, K.; Takahashi, A.; Uda, H. J .
Org. Chem. 1987, 52, 1078-1082.
(11) For palladium-catalyzed carbozincation with PdCl2(dppf), see:
Stadtmu¨ller, H.; Vaupel, A.; Tucker, C. E.; Stu¨demann, T.; Knochel,
P. Chem. Eur. J . 1996, 2, 1204-1220.
J . Org. Chem, Vol. 68, No. 14, 2003 5551

Maezaki et al.
TABLE 2. P d -Ca ta lyzed Su lfin ylzin ca tion of 1-Alk yn yl
SCHEME 4
p-Tolyl Su lfoxid es 1b-fa
entry substrate
R
time (h) product (yield, %)b
1
2
3
4
5
1b
1c
1d
1e
1f
TBSO(CH2)2
AcO(CH2)2
I(CH2)4
H
1.5
1.5
1.5
0.5
2b (88); 3b (0)
2c (82); 3c (0)
2d (97); 3d (0)
2e (24);c 3e (33)d
complex mixture
t-Bu
12
a
All reactions were carried out with Pd2(dba)3‚CHCl3 (2 mol
%) and Et2Zn (2 equiv) in THF solution at -78 °C to room
temperature. Isolated yield and the yields of 2 are based on 50%
b
of 1. The ratio of diastereomeric isomers is ca. 1:1 unless otherwise
d
stated. c Single diastereomeric isomer. The ratio of (E/Z)-isomers
is 2:1.
mixture of 3e12 was produced along with 2e (entry 4).
Compound 1f bearing a bulky tert-butyl group afforded
a complex mixture (entry 5).
P la u sible Rea ction Mech a n ism of P d -Ca ta lyzed
Su lfin ylzin ca tion . We suggest the two reaction mech-
anisms of Pd-catalyzed sulfinylzincation as depicted in
Scheme 4. The reaction would be initiated by oxidative
addition of 1-alkynyl sulfoxides to a Pd(0) complex.13
Then, sulfinylpalladium species I would be transmeta-
lated with Et2Zn, giving the zinc sulfenate species IIa
presumably as a equilibrium mixture with sulfinylzinc
species IIb. Subsequent addition of the zinc sulfenate to
the 1-alkynyl sulfoxide would afford bis-sulfinyl vinylzinc
species IV. On the other hand, the ethylpalladium
intermediate III undergoes â-hydride elimination and
regenerates the Pd(0)-catalyst (pathway a). A direct
sulfinylpalladation to the 1-alkynyl sulfoxides (IfVI) is
another possible reaction mechanism (pathway b). The
resulting alkenylpalladium species VI was transmeta-
lated to give the bis-sulfinyl vinylzinc species IV.
We cannot conclude which pathway is actual at the
present time, but assume that pathway a would be more
preferable than pathway b from the following: (1)
Although insertion of alkyne into the C-Pd-X interme-
diate (X ) halogen and triflate) regularly occurs at the
C-Pd bond, no product arising from insertion of 1-al-
kynyl sulfoxide into the C-Pd bond of intermediate I was
obtained. (2) Although Et2Zn plays a role only to regener-
ate the Pd(0)-catalyst in pathway b, no bis-sulfinyl alkene
was formed without Et2Zn despite the use of a stoichio-
metric amount of Pd2(dba)3‚CHCl3 (0.5 equiv).
SCHEME 5
compounds 6 and 714 in 91% and 96% yield, respec-
tively.15 When the reaction was quenched with AcOD, the
corresponding deuterated products 8 and 9 were pro-
duced in 78% and 98% yield, respectively.15 In contrast
to the 86% deuteration of the bis-sulfinyl alkene 8, only
52% deuteration was observed in the alkyne 9.
The results are rationalized as follows. As shown in
Scheme 4, most of the p-tolylsulfinyl group of the oxida-
tive adduct I in pathway a (or the alkenyl group of adduct
VI in pathway b) would be transmetalated to zinc, giving
the bis-sulfinyl alkene V (8, R ) CtC(CH2)2OTBDPS)
after deuteration of IV. On the other hand, only half of
the alkynyl group of I (or VI) would be converted by
transmetalation A into the zinc salts IV (X ) CtC(CH2)2-
OTBDPS), which led to the deuterated alkyne 9. The
other half of the alkynyl group of I (or VI) would be
Next, we investigated the reaction of alkynyl sulfoxide
1g bearing an alkyne moiety with low volatility to ex-
amine the reaction of the alkyne part in intermediate I
(Scheme 5). Sulfinylzincation with 1g and subsequent
trapping of the resulting anion with AcOH provided two
(12) Marsan, M.-P.; Warnock, W.; Muller, I.; Nakatani, Y.; Ourisson,
G.; Milon, A. J . Org. Chem. 1996, 61, 4252-4257.
(13) The oxidative addition of Pd(0) to the carbon-sulfur bond of
the thioalkynes was reported, see: Savarin, C.; Srogel, J .; Liebeskind,
L. S. Org. Lett. 2001, 3, 91-93.
(14) Sinha, S. C.; Shinha, S. C.; Keinan, E. J . Org. Chem. 1999, 64,
7067-7073.
(15) These yields were calculated on the basis of a theoretical
maximum 50% yield.
5552 J . Org. Chem., Vol. 68, No. 14, 2003

Pd-Catalyzed Sulfinylzincation
TABLE 3. P d -Ca ta lyzed Su lfin ylzin ca tion of
1-Alk yn oa tes 11a -j w ith 1-Alk yn yl Su lfoxid e 1f
SCHEME 6
entry
substrate
R
R′
product (yield, %)b
1
2
3
4
5
6
7
8
9
10
11
12
13
11a
11b
11c
11c
11d
11e
11f
11g
11h
11i
11i
11j
11j
H
Me
CH2OBn
CH2OBn
Me
Et
12a (87)
12b (62)
12c (100)
12c (92)c
12d (97)
(E)-12e (93)
12f (48)
SCHEME 7
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
Me
CH2OAc
CH2OTBS
CH2CH2Bn
(CH2)2OBn
(CH2)3OBn
CH2SBn
CH2SBn
CH2N(Me)Bn
CH2N(Me)Bn
12g (57)
12h (48)
12i (98)
12i (83)c
12j (98)
12j (68)c
a
All reactions were carried out with 1-alkynoate (10 equiv),
Pd2(dba)3‚CHCl3 (2 mol %), and Et2Zn (2 equiv) in THF solution
b
at -78 °C to room temperature. Isolated yield. c 2 equiv of
1-alkynoate was used.
transformed into the ethylpalladium species III (Y ) Ct
C(CH2)2OTBDPS) by transmetalation B, giving the pro-
tonated alkyne 7 via subsequent â-hydride elimination.
Accordingly, the ratio of deuteration was lower for the
alkyne 9 than that for the bis-sulfinyl alkene 8.
equiv) with Pd2(dba)3‚CHCl3 (2 mol %) and Et2Zn (2
equiv) in THF (0.1 M) to furnish (E)-3-(p-tolylsulfinyl)-
acrylate derivatives 12a and 12b in 87% and 62% yield,
respectively (Table 3, entries 1 and 2). The reaction
proceeded with high syn-selectivity, giving (E)-isomers
as the sole geometric isomer.18 Sulfinylzincation pro-
ceeded in alkynoates 11c-f bearing functionalized sub-
stituents (entries 3-7). Substrate 11f having a â-alkyl
substituent exhibited reduced yield compared to the
unsubstituted methyl propiolate 11a . However, in the
substrates 11c-e bearing a δ-oxygen, the yields of
adducts 12c-e were dramatically improved. Comparing
the yields of both 12c (R ) CH2OBn) and 12f (R ) CH2-
CH2Bn), it is obvious that the δ-oxygen plays some role
to enhance the reaction. The effect was changed depend-
ing on the protecting group on the hydroxy group. Both
the electron-withdrawing acetyl group and the sterically
hindered TBS group slightly decreased the yields com-
pared with the benzyl ether. The position of the oxygen
atom also affected the yield (entries 3, 8, and 9). When
the ether oxygen atom exists at the δ-position of the
alkynoates, the reaction showed the best yield. The yield
was reduced with increasing the distance of the oxygen
from the reaction site. When the oxygen exists three
carbons apart from the reaction site, the yield was the
same as that of the methylene compound 12f (entries 7
and 9). Enhancement of yields was observed in thioether
12i and tertiary amine 12j as well as in benzyl ether 12c.
The effect was reduced in the order of O > S > NMe
(entries 3, 4, and 10-13). Obviously, the heteroatom at
the δ-position exhibited a considerable neighboring effect,
although the efficiency is different.
We also examined the sulfinylzincation without a Pd-
catalyst as shown in entry 7 of Table 1 in detail. We
assumed that there exists a different pathway to generate
the zinc sulfenate species. When the reaction of 1g was
carried out in the absence of a Pd-catalyst, the bis-sulfinyl
alkene 6 was produced via sulfinylzincation in 85% yield
(Scheme 6). In sharp contrast to Pd-catalyzed sulfinyl-
zincation, 3-hexyn-1-ol TBDPS ether (10a ) and 4-(tetra-
hydrofuran-2-yl)-3-butyn-1-ol TBDPS ether (10b) were
formed instead of 7 in 40% and 29% yield, respectively.15
Obviously, the reaction mechanism was different from
that of the Pd-catalyzed reaction. In this case, the zinc
sulfenate species would be produced by the radical
substitution reaction of the 1-alkynyl sulfoxides with the
ethyl radical or the 2-tetrahydrofuranyl radical generated
by radical transfer from the initially formed ethyl radical
to the solvent.16 A similar substitution reaction of acety-
lenic sulfones has been reported.17
P d -Ca ta lyzed Su lfin ylzin ca tion w ith 1-Alk yn yl
Su lfoxid e Bea r in g a Bu lk y â-Su bstitu en t. If the self-
reaction of the zinc sulfenate species with the 1-alkynyl
sulfoxide could be suppressed, the species would be
trapped with other activated alkynes as shown in Scheme
7. As mentioned above, we found that the reaction of
1-alkynyl sulfoxide 1f was sluggish and did not undergo
the self-reaction presumably due to steric bulkiness of
the tert-butyl group (Table 2, entry 5). Therefore, we
attempted the sulfinylzincation of alkynoates with the
sulfinylating agent 1f. Since chirality on the sulfur was
lost during sulfinylzincation, the following experiments
were conducted with racemic 1-alkynyl sulfoxides.
As we expected, the zinc sulfenate was trapped with
alkynoates 11a and 11b (10 equiv) on treatment of 1f (1
The observed activation of the sulfinylzincation by the
neighboring heteroatom would be rationalized in that
coordination of the heteroatom to the zinc cation would
assist the sulfinylzincation by directing the sulfur atom
to the reaction site (Figure 1). We demonstrated the
(16) Yamamda, K.; Fujihara, H.; Yamamoto, Y.: Miwa, Y.: Taga,
T.; Tomioka, K. Org. Lett. 2002, 4, 3509-3511. Gong, J .; Fuchs, P. L.
J . Am. Chem. Soc. 1996, 118, 4486-4487.
(17) Back, T. G. Tetrahedron 2001, 57, 5263-5301 and references
therein.
(18) All attempts to isolate zinc sulfenate species failed presumably
due to its instability.
J . Org. Chem, Vol. 68, No. 14, 2003 5553

Maezaki et al.
SCHEME 9
F IGURE 1.
SCHEME 8
SCHEME 10
TABLE 4. P d -Ca ta lyzed Su lfin ylzin ca tion of Activa ted
Alk yn es w ith 1-Alk yn yl Su lfoxid esa
activated
entry alkyne
1-alkynyl
sulfoxide
product
EWG
R
(yield, %)b
1
2
3
4
5
6
7
8
9
11c
11c
11c
11c
11c
11c
11c
11c
11c
11k
11l
CO2Me
CO2Me
CO2Me
CO2Me
CO2Me
CO2Me
CO2Me
CO2Me
CO2Me
CONMe2
CN
1f
1h
1i
1i
1j
1j
1k
1l
1m
1f
1f
Tol (p-C6H4Me) 12c (92)
p-C6H4OMe
C6H5
12k (83)
12l (69)
12l (86)c
12m (69)
12m (82)c
12n (26)
12o (73)
12p (46)
12q (59)
12r (27)
C6H5
Since the Michael addition of thiolates to activated
alkynes proceeds with anti-selectivity,19 sulfinylzincation
affords a complementary procedure to the anti-selective
methodology. We demonstrated stereodivergent synthesis
of (E)- and (Z)-â-sulfinyl enoates (E)- and (Z)-12e from
the common alkynoate 11e. Both geometric isomers were
prepared in excellent yields and with high stereoselec-
tivity (Scheme 9).
The vinylzinc species resulting from sulfinylzincation
can be trapped with carbon electrophiles after trans-
metalation with CuCN‚2LiCl. The reaction with allyl-
bromide and benzoyl chloride afforded tetrasubstituted
alkenes 16 and 17 in 74% and 62% yield, respectively
(Scheme 10). It is noteworthy that no isomerization of
the alkene stereochemistry occurred during these reac-
tions and highly functionalized alkenes were formed
stereoselectively.
p-C6H4Cl
p-C6H4Cl
p-C6H4NO2
Me
(CH2)3CtCH
Tol
10
11
Tol
a
All reactions were carried out with 1-alkynoate (2 equiv),
Pd2(dba)3‚CHCl3 (2 mol %), and Et2Zn (2 equiv) in THF solution
at -78 °C to room temperature. Isolated yield. c 5 equiv of
b
1-alkynoate was used.
selective sulfinylation of bis-alkynoate 13. The sulfinyl-
zincation absolutely proceeded to the alkynoate bearing
a δ-oxygen to furnish 14 as the sole product (Scheme 8).
Next, we examined the influence of a para-substituent
in the arylsulfinyl group on the yield of sulfinylzincation
to 11c using 1-alkynylsulfoxides 1f,h -k . The results are
shown in Table 4. Electron-withdrawing substituents led
to a decrease in the yields presumably due to lowering
nucleophilicity of the sulfenate anions. The order of yields
is consistent with the order of the electron-donating
nature of the para-substituents, i.e. NO2 < Cl < H < Me.
However, the most nucleophilic 1h (R ) OMe) rather
showed lower yield than 1f (R ) Me) (entries 1-7). The
reason has not been ascertained, but we assume that the
decreased yield stems from the instability of the zinc
sulfenate species, or was caused by effects on the oxida-
tive addition and the transmetalation steps.
Con clu sion
In conclusion, we have developed novel Pd-catalyzed
sulfinylzincation using 1-alkynyl sulfoxides as a sulfinyl
source. The reaction is tolerant of a range of functional
groups, and provides tri- and tetrasubstituted alkynes
regio- and stereoselectively. In the substrates having a
heteroatom at the δ-position, the yield was considerably
increased presumably by coordination of a heteroatom
in the substrate to the zinc sulfenate intermediate. This
methodology also can be complementarily used in com-
bination with conjugate addition of thiolate and subse-
quent oxidation, leading to an anti-adduct.
An alkylsulfinyl group could be transferred by this
method. Sulfinylzincation of the alkynoates 11c with 1l
and 1m gave adducts 12o and 12p , respectively, in
moderate yields (entries 8 and 9). Sulfinylzincation of
other activated alkynes was also examined. Thus, alkyn-
amide 11k and alkynylnitrile 11l were sulfinylated to
give 12q and 12r in 59% and 27% yield, respectively
(entries 10 and 11).
Exp er im en ta l Section
All melting points are uncorrected. NMR spectra were
recorded in CDCl3 solution at 500 or 300 MHz (1H), and 125
(19) Perlmutter, P. In Conjugate Addition Reactions in Organic
Synthesis; Baldwin, J . E., Magnus, P. D., Eds.; Pergamon Press:
Oxford, UK, 1992; Vol. 9, pp 310-322 and references therein.
5554 J . Org. Chem., Vol. 68, No. 14, 2003

Pd-Catalyzed Sulfinylzincation
or 75 MHz (13C). IR absorption spectra (FT: diffuse reflectance
spectroscopy) were recorded with KBr powder, and only
noteworthy absorptions (cm-1) are listed. Column chromatog-
raphy was carried out with Kanto Chemical silica gel 60 (63-
210 µm). All air- or moisture-sensitive reactions were carried
out in flame-dried glassware under an atmosphere of Ar. All
solvents were dried and distilled according to standard pro-
cedures. All organic extracts were dried over anhydrous
MgSO4, filtered, and concentrated with a rotary evaporator
under reduced pressure.
Gen er a l P r oced u r e for th e Syn th esis of Bis-su lfin yl
Alk en es by Su lfin ylzin ca t ion (Ta b le 1, en t r y 6). Et2Zn
(0.99 M in n-hexane) (0.36 mL, 0.354 mmol) was added slowly
to a solution of 1-hexynyl p-tolyl sulfoxide (39.0 mg, 0.177
mmol) and Pd2(dba)3‚CHCl3 (3.7 mg, 0.00354 mmol) in THF
(1.8 mL) with stirring at -78 °C. After 15 min, the dry ice
bath was removed and the stirring was continued for 2 h. The
reaction was quenched with saturated NH4Cl and extracted
with Et2O. The organic layer was washed with brine prior to
drying and solvent evaporation. The residue was chromato-
graphed on silica gel with hexane-AcOEt (3:1) to give 2a (30.3
mg, 95%) as a colorless oil.
was stirred for 1 h. The mixture was extracted with AcOEt
and washed with brine prior to drying and solvent evaporation.
The residue was chromatographed on silica gel with hexane-
1
AcOEt (3:1) to give 5 (125 mg, 98%) as a yellow oil. H NMR
δ 0.74 (t, 3H, J ) 7.5 Hz), 1.04-1.19 (m, 2H), 1.31-1.43 (m,
2H), 2.12-2.17 (m, 2H), 2.37 (s, 3H), 2.42 (s, 3H), 6.30 (s, 1H),
7.17 (d, 2H, J ) 8.0 Hz), 7.32 (d, 2H, J ) 8.0 Hz), 7.35 (d, 2H,
J ) 8.0 Hz), 7.58 (d, 2H, J ) 8.0 Hz). 13C NMR δ 13.6, 21.2,
21.4, 21.7, 30.1, 35.6, 124.1 (2C), 127.3, 129.9 (2C), 130.0 (2C),
133.6 (2C), 135.3, 139.0, 140.6, 141.8, 150.8. IR 1041. MS (FAB)
m/z 345 (MH+). HRMS (FAB) calcd for C20H25OS2 (MH+)
345.1347, found 345.1344.
(Z)-1,2-Bis(p-tolylsu lfon yl)-1-h exen e [(Z)-4]. By the same
procedure as for (E)-4 from 2a , 5 (42.1 mg, 0.122 mmol) was
converted into (Z)-4 (73.5 mg, quant). Yellow oil. 1H NMR δ
0.83 (t, J ) 7.3 Hz, 3H), 1.26 (tq, J ) 7.5, 7.3 Hz, 2H), 1.39 (tt,
J ) 7.5, 7.5 Hz, 2H), 2.39 (td, J ) 7.5, 1.5 Hz, 2H), 2.46 (s,
6H), 6.72 (t, J ) 1.5 Hz, 1H), 7.35 (d, J ) 8.0 Hz, 2H), 7.35 (d,
J ) 8.0 Hz, 2H), 7.91 (d, J ) 8.0 Hz, 2H), 7.96 (d, J ) 8.0 Hz,
2H). 13C NMR δ 13.5, 21.66, 21.71, 21.9, 30.3, 33.2, 128.2 (2C),
129.0 (2C), 129.6 (2C), 129.9 (2C), 135.7, 138.3, 138.5, 144.8,
145.6, 153.9. IR 1159, 1081. MS (FAB) m/z 393 (MH+). HRMS
(FAB) calcd for C20H25O4S2 (MH+) 393.1194, found 393.1188.
(E)-4-(ter t-Bu tyld im eth ylsilyloxy)-1,2-bis(p-tolylsu lfin -
yl)-1-bu ten e (2b): Colorless oil (1:1 diastereomeric mixture).
1H NMR δ 0.03-0.05 (m, 6H), 0.89 (s, 9H), 2.24 (dt, J ) 14.5,
7.2 Hz, 0.5H), 2.31 (dt, J ) 14.3, 7.2 Hz, 0.5H), 2.41 (s, 3H),
2.43 (s, 1.5H), 2.44 (s, 1.5H), 2.99 (dt, J ) 14.3, 6.3 Hz, 0.5H),
3.08 (dt, J ) 14.5, 6.3 Hz, 0.5H), 3.60-3.77 (m, 2H), 7.12 (s,
0.5H), 7.19 (s, 0.5H), 7.29 (d, J ) 7.9 Hz, 2H), 7.34 (d, J ) 7.9
Hz, 2H), 7.43 (d, J ) 8.2 Hz, 1H), 7.52 (d, J ) 8.2 Hz, 2H),
7.57 (d, J ) 8.2 Hz, 1H). 13C NMR δ -5.5 (2C), 18.2, 21.3, 21.4,
25.8 (3C), 30.4 (0.5C), 30.7 (0.5C), 61.8 (0.5C), 62.3 (0.5C),
124.2, 124.5, 126.0, 126.3, 130.1 (2C), 130.2 (2C), 135.5 (0.5C),
135.9 (0.5C), 138.1 (0.5C), 138.5 (0.5C), 140.2 (0.5C), 140.4
(0.5C), 141.8 (0.5C), 141.9 (0.5C), 142.8 (0.5C), 143.0 (0.5C),
154.3 (0.5C), 155.1 (0.5C). IR 1051. MS (FAB) m/z 463 (MH+).
HRMS (FAB) calcd for C24H35O3S2Si (MH+) 463.1797, found
463.1815.
(E)-1,2-Bis(p-tolylsu lfin yl)-1-h exen e (2a ): Colorless oil
1
(1:1 diastereomeric mixture). H NMR δ 0.87 (t, J ) 7.3 Hz,
1.5H), 0.88 (t, J ) 6.7 Hz, 1.5H), 1.35 (m, 2H), 1.44 (m, 1H),
1.59 (m, 1H), 2.03 (ddd, J ) 14.6, 9.2, 5.5 Hz, 0.5H), 2.11 (ddd,
J ) 14.6, 9.2, 5.5 Hz, 0.5H), 2.43 (s, 3H), 2.43 (s, 1.5H), 2.44
(s, 1.5H), 2.69 (ddd, J ) 14.6, 9.2, 6.7 Hz, 0.5H), 2.80 (ddd,
J ) 14.6, 9.2, 6.7 Hz, 0.5H), 7.07 (s, 0.5H), 7.12 (s, 0.5H), 7.27
(d, J ) 7.9 Hz, 1H), 7.29 (d, J ) 7.9 Hz, 1H), 7.34 (d, J ) 7.9
Hz, 2H), 7.41 (d, J ) 8.1 Hz, 1H), 7.50 (d, J ) 8.1 Hz, 1H),
7.52 (d, J ) 8.1 Hz, 1H), 7.56 (d, J ) 8.1 Hz, 1H). 13C NMR δ
13.5, 21.4, 21.5, 22.4 (0.5C), 22.5 (0.5C), 26.5 (0.5C), 26.9 (0.5C),
31.7 (0.5C), 31.8 (0.5C), 124.2, 124.5, 125.9, 126.2, 130.2 (4C),
134.0 (0.5C), 134.8 (0.5C), 138.0 (0.5C), 138.5 (0.5C), 140.3
(0.5C), 140.4 (0.5C), 141.9 (0.5C), 142.1 (0.5C), 142.9 (0.5C),
143.1 (0.5C), 157.3 (0.5C), 158.0 (0.5C). IR 1051. MS (FAB)
m/z 361 (MH+). HRMS (FAB) calcd for C20H25O2S2 (MH+)
361.1296, found 361.1291.
(Z,Rs)-2-Eth ylh ex-1-en yl p-Tolyl Su lfoxid e (3a ): Yellow
(E)-3,4-Bis(p-tolylsu lfin yl)-3-bu ten yl a ceta te (2c): Col-
orless oil (1:1 diastereomeric mixture). 1H NMR δ 2.06 (s,
1.5H), 2.07 (s, 1.5H), 2.39-2.49 (m, 7H), 3.16 (dt, J ) 14.7,
6.7 Hz, 1H), 4.06-4.17 (m, 2H), 7.14 (s, 0.5H), 7.19 (s, 0.5H),
7.28-7.37 (m, 4H), 7.44-7.59 (m, 4H). 13C NMR δ 20.78 (0.5C),
20.81 (0.5C), 21.4, 21.5, 25.9 (0.5C), 26.2 (0.5C), 62.1 (0.5C),
62.4 (0.5C), 124.2 (0.5C), 124.3, 124.5, 125.8, 126.1, 129.9
(0.5C), 130.31 (1.5C), 130.35, 133.4 (0.5C), 136.4, 136.8, 137.7
(0.5C), 138.0 (0.5C), 139.89 (0.5C), 139.94 (0.5C), 142.2 (0.5C),
142.3 (0.5C), 143.1 (0.5C), 143.3 (0.5C), 170.5 (0.5C), 170.6
(0.5C). IR 1741, 1047. MS (FAB) m/z 391 (MH+). HRMS (FAB)
calcd for C20H23O4S2 (MH+) 391.1037, found 391.1035.
(E)-6-Iod o-1,2-bis(p-tolylsu lfin yl)-1-h exen e (2d ): Color-
less oil (1:1 diastereomeric mixture). 1H NMR δ 1.43-1.57 (m,
2H), 1.78-1.83 (m, 2H), 2.09 (ddd, J ) 14.7, 9.7, 5.5 Hz, 0.5H),
2.18 (ddd, J ) 14.7, 9.7, 5.5 Hz, 0.5H), 2.42 (s, 3H), 2.44 (s,
1.5H), 2.50 (s, 1.5H), 2.71 (ddd, J ) 14.7, 9.8, 6.1 Hz, 0.5H),
2.79 (ddd, J ) 14.7, 9.8, 6.1 Hz, 0.5H), 3.04 (t, J ) 6.7 Hz,
2H), 7.01 (s, 0.5H), 7.13 (s, 0.5H), 7.29 (d, J ) 7.3 Hz, 1H),
7.31 (d, J ) 7.3 Hz, 1H), 7.36 (d, J ) 7.3 Hz, 2H), 7.44 (d, J )
8.0 Hz, 1H), 7.52 (d, J ) 8.0 Hz, 2H), 7.58 (d, J ) 8.0 Hz, 1H).
13C NMR δ 5.2 (0.5C), 5.4 (0.5C), 21.5 (2C), 25.5 (0.5C), 25.9
(0.5C), 30.3 (0.5C), 30.5 (0.5C), 32.7, 124.3, 124.6, 125.9, 126.3,
130.3 (4C), 134.6 (0.5C), 135.2 (0.5C), 137.9 (0.5C), 138.3
(0.5C), 140.1, 142.1 (0.5C), 142.3 (0.5C), 143.1 (0.5C), 143.3
(0.5C), 156.4 (0.5C), 156.8 (0.5C). IR 1051. MS (FAB) m/z 487
(MH+). HRMS (FAB) calcd for C20H24IO2S2 (MH+) 487.0263,
found 487.0287.
1
oil. [R]22 -181.0 (c 0.51, CHCl3). H NMR δ 0.96 (t, J ) 7.2
D
Hz, 3H), 1.03 (t, J ) 7.3 Hz, 3H), 1.25-1.48 (m, 2H), 1.49-
1.63 (m, 2H), 2.19 (q, J ) 7.3 Hz, 2H), 2.41 (s, 3H), 2.48-2.69
(m, 2H), 6.00 (s, 1H), 7.30 (d, J ) 8.1 Hz, 2H), 7.49 (d, J ) 8.1
Hz, 2H). 13C NMR δ 11.5, 13.8, 21.3, 22.7, 29.2, 31.0, 32.2,
124.1 (2C), 129.8 (2C), 130.7, 140.7, 141.8, 158.0. IR 1041. MS
(FAB) m/z 251 (MH+). HRMS (FAB) calcd for C15H23OS (MH+)
251.1470, found 251.1469.
(E)-1,2-Bis(p-tolylsu lfon yl)-1-h exen e [(E)-4]. m-CPBA
(containing 30% water) (47.2 mg, 0.19 mmol) was added to a
solution of 2a (31.4 mg, 0.087 mmol) in CH2Cl2 (0.9 mL) with
stirring at 0 °C, and the mixture was stirred at 0 °C. The
stirring was continued at 0 °C for 15 min, and then at room
temperature for 1 h. The mixture was quenched with saturated
NaHCO3, and extracted with CHCl3. The organic layer was
washed with brine prior to drying and solvent evaporation.
The residue was purified by PTLC with CHCl3 to give (E)-4
(27.0 mg, 79%) as colorless columns. Mp 153.0-154.0 °C
1
(AcOEt-hexane). H NMR δ 0.83 (t, 3H, J ) 7.3 Hz), 1.26-
1.34 (m, 2H), 1.36-1.56 (m, 2H), 2.47 (s, 3H), 2.48 (s, 3H), 2.69
(t, 2H, J ) 7.9 Hz), 7.33 (s, 1H), 7.37 (d, 2H, J ) 7.9 Hz), 7.39
(d, 2H, J ) 7.9 Hz), 7.71 (d, 2H, J ) 7.9 Hz), 7.80 (d, 2H, J )
7.9 Hz). 13C NMR δ 13.4, 21.7 (2C), 23.0, 26.6, 31.8, 127.9 (2C),
128.8 (2C), 130.2 (2C), 130.3 (2C), 134.2, 135.1, 136.8, 145.7,
145.8, 154.7. IR 1319, 1153. MS (FAB) m/z 393 (MH+). HRMS
(FAB) calcd for C20H25O4S2 (MH+) 393.1194, found 393.1199.
(Z)-2-(p-Tolylth io)-1-h exen yl p-Tolyl Su lfoxid e (5). A
mixture of p-toluenethiol (55.4 mg, 0.446 mmol) and Et3N (32
µL, 0.446 mmol) in MeOH (10 mL) was stirred at room
temperature for 10 min. Then, a solution of 1a (81.9 mg, 0.372
mmol) was added to the mixture at -10 °C. After 30 min, the
temperature was raised to room temperature and the solution
(E)-1,2-Bis(p-tolylsu lfin yl)eth en e (2e): Colorless needles.
Mp 191.0-192.5 °C (hexane-AcOEt). [R]24 +807 (c 0.60,
D
1
CHCl3). H NMR δ 2.43 (s, 6H), 7.21 (s, 2H), 7.31 (d, J ) 8.3
Hz, 4H), 7.44 (d, J ) 8.3 Hz, 4H). 13C NMR δ 21.5 (2C), 125.1
(4C), 130.4 (4C), 139.0 (2C), 141.7 (2C), 142.7 (2C). IR 1051.
J . Org. Chem, Vol. 68, No. 14, 2003 5555

Maezaki et al.
MS (FAB) m/z 305 (MH+). HRMS (FAB) calcd for C16H17O2S2
m/z 225 (MH+). HRMS (FAB) calcd for C11H13O3S 225.0585,
found 225.0580.
(MH+) 305.0670, found 305.0681.
Eth yl (E)-3-(p-tolylsu lfin yl)-2-bu ten oa te (12b): Yellow
oil. 1H NMR δ 1.32 (t, J ) 7.0 Hz, 3H), 2.04 (d, J ) 1.5 Hz,
3H), 2.41 (s, 3H), 4.42 (q, J ) 7.0 Hz, 2H), 6.74 (q, J ) 1.5 Hz,
1H), 7.31 (d, J ) 8.0 Hz, 2H), 7.53 (d, J ) 8.0 Hz, 2H). 13C
NMR δ 12.5, 14.1, 21.4, 60.7, 118.7, 126.0 (2C), 130.2 (2C),
138.2, 142.7, 160.9, 164.7. IR 1716, 1059. MS (EI) m/z 252 (M+).
HRMS (EI) calcd for C13H16O3S (M+) 252.0820, found 252.0825.
Meth yl (E)-4-ben zyloxy-3-(p-tolylsu lfin yl)-2-bu ten oa te
(12c): Yellow oil. 1H NMR δ 2.39 (s, 3H), 3.76 (s, 3H), 4.06
(dd, J ) 15.0, 2.0 Hz, 1H), 4.33 (d, J ) 11.5 Hz, 1H), 4.49 (d,
J ) 11.5 Hz, 1H), 5.10 (dd, J ) 15.0, 2.0 Hz, 1H), 6.83 (t, J )
2.0 Hz, 1H), 7.23-7.36 (m, 7H), 7.52 (d, J ) 8.5 Hz, 2H). 13C
NMR δ 21.4, 51.9, 65.2, 73.1, 118.1, 126.1 (2C), 127.8 (2C),
127.9, 128.4 (2C), 130.0 (2C), 136.9, 139.0, 142.4, 163.9, 164.9.
IR 1720, 1049. MS (FAB) m/z 345 (MH+). HRMS (FAB) calcd
for C19H21O4S (MH+) 345.1160, found 345.1162.
(E)-4-(ter t-Bu tyld ip h en ylsilyloxy)-1,2-bis(p-tolylsu lfin -
yl)-1-bu ten e (6): Yellow oil. 1H NMR δ 1.05 (s, 9H), 2.19-2.25
(m, 0.5H), 2.31-2.42 (m, 6.5H), 3.02 (dt, J ) 13.4, 7.3 Hz,
0.5H), 3.16 (dt, J ) 13.4, 6.7 Hz, 0.5H), 3.63-3.87 (m, 2H), 7.10
(s, 0.5H), 7.16-7.66 (m, 18.5H). 13C NMR δ 19.0, 21.4, 21.5,
26.8 (3C), 30.3 (0.5C), 30.6 (0.5C), 62.8 (0.5C), 63.1 (0.5C),
124.3, 124.6, 126.0, 126.4, 127.6, 127.8, 129.6, 129.8, 129.9,
130.17 (0.5C), 130.22 (0.5C), 130.24 (0.5C), 130.3 (0.5C), 133.00
(0.5C), 133.04 (0.5C), 133.1 (0.5C), 133.2 (0.5C), 135.5 (2C),
136.1, 138.1, 138.5, 140.1, 140.4, 141.9, 142.0, 142.8, 143.1,
153.7, 154.9. IR 1086. MS (FAB) m/z 587 (MH+). HRMS (FAB)
calcd for C34H39O3SiS2 (MH+) 587.2110, found 587.2104.
(E)-4-(ter t-Bu tyld ip h en ylsilyloxy)-1-d eu ter io-1,2-bis(p-
tolylsu lfin yl)-1-bu ten e (8) a n d 4-Deu ter io-3-bu tyn -1-ol
ter t-Bu tyld ip h en ylsilyl Eth er (9). The reaction was carried
out according to the general procedure for synthesis of the bis-
sulfinyl alkenes, but quenching with AcOD instead of NH4Cl.
8: Yellow oil. 1H NMR δ 1.05 (s, 9H), 2.19-2.25 (m, 0.5H),
2.31-2.42 (m, 6.5H), 3.02 (dt, J ) 13.4, 7.3 Hz, 0.5H), 3.16
(dt, J ) 13.4, 7.3 Hz, 0.5H), 3.63-3.87 (m, 2H), 7.10 (s, 0.07H),
7.16-7.66 (m, 18.07H). 13C NMR δ 19.1, 21.4, 21.5, 26.8 (3C),
30.2 (0.5C), 30.6 (0.5C), 62.9 (0.5C), 63.1 (0.5C), 124.3, 124.6,
126.0, 126.4, 127.77, 127.81, 129.80, 129.84, 129.9, 130.17
(0.5C), 130.22 (0.5C), 130.24 (0.5C), 130.3 (0.5C), 133.00 (0.5C),
133.04 (0.5C), 133.1 (0.5C), 133.2 (0.5C), 135.5 (2C), 136.1,
138.1, 138.5, 140.1, 140.4, 141.9, 142.0, 142.8, 143.1, 153.68
(0.5C), 153.78 (0.5C), 154.87 (0.5C), 154.93 (0.5C). IR 1595,
1086. MS (FAB) m/z 610 (MNa+). HRMS (FAB) calcd for
C34H37DO3SiS2Na (MNa+) 610.1992, found 610.1990. 9: Yellow
Met h yl (E)-4-a cet oxy-3-(p -t olylsu lfin yl)-2-b u t en oa t e
1
(12d ): Yellow oil. H NMR δ 1.97 (s, 3H), 2.41 (s, 3H), 3.81 (s,
3H), 4.63 (d, J ) 14.5 Hz, 1H), 5.48 (d, J ) 14.5 Hz, 1H), 6.91
(s, 1H), 7.31 (d, J ) 8.0 Hz, 2H), 7.55 (d, J ) 8.0 Hz, 2H). 13C
NMR δ 20.4, 21.5, 52.2, 58.4, 120.7, 126.3 (2C), 130.3 (2C),
138.1, 143.2, 159.5, 164.4, 169.7. IR 1747, 1720, 1435, 1041.
MS (FAB) m/z 297 (MH+). HRMS (FAB) calcd for C14H17O5S
(MH+) 297.0797, found 297.0797.
Met h yl (E)-4-(ter t-b u t yld im et h ylsilyloxy)-3-(p -t olyl-
su lfin yl)-2-bu ten oa te [(E)-12e]: Yellow oil. 1H NMR δ -0.03
(s, 3H), 0.02 (s, 3H), 0.86 (s, 9H), 2.38 (s, 3H), 3.75 (s, 3H),
4.21 (dd, J ) 16.0, 2.5, Hz, 1H), 5.32 (dd, J ) 16.0, 2.5 Hz,
1H), 6.69 (dd, J ) 2.5, 2.5 Hz, 1H), 7.26 (d, J ) 8.0 Hz, 2H),
7.56 (d, J ) 8.0 Hz, 2H). 13C NMR δ -5.7, -5.6, 18.2, 21.4,
25.7 (3C), 51.8, 59.9, 116.2, 126.2 (2C), 130.0 (2C), 139.3, 142.2,
165.0, 166.8. IR 1718, 1097. MS (FAB) m/z 369 (MH+). HRMS
(FAB) calcd for C18H29O4SSi (MH+) 369.1556, found 369.1559.
Met h yl (E)-6-p h en yl-3-(p -t olylsu lfin yl)-2-h exen oa t e
(12f): Yellow oil. 1H NMR δ 1.43-1.67 (m, 1H), 1.69-1.80 (m,
1H), 2.14 (ddd, J ) 13.8, 10.5, 4.8 Hz, 1H), 2.40 (s, 3H), 2.49-
2.62 (m, 2H), 2.73 (ddd, J ) 13.8, 10.5, 5.7 Hz, 1H), 3.75 (s,
3H), 6.74 (s, 1H), 7.04-7.42 (m, 9H). 13C NMR δ 21.5, 26.8,
30.3, 35.6, 51.7, 117.7, 125.9, 126.2 (2C), 128.3 (2C), 128.4 (2C),
130.2 (2C), 138.2, 141.2, 142.8, 165.0, 165.7. IR 1720, 1090.
MS (FAB) m/z 343 (MH+). HRMS (FAB) calcd for C20H23O3S
(MH+) 343.1368, found 343.1374.
1
oil. H NMR δ 1.06 (s, 9H), 1.94 (t, J ) 2.5 Hz, 0.47H), 2.45
(td, J ) 7.0, 2.5 Hz, 1H), 3.78 (t, J ) 7.0 Hz, 2H), 7.36-7.68
(m, 10H). 13C NMR δ 19.2, 22.6, 26.8 (3C), 62.3, 69.3, 81.5,
127.7 (4C), 129.7 (2C), 133.6 (2C), 135.6 (4C). IR 2121. MS
(FAB) m/z 316 (MLi+). HRMS (FAB) calcd for C20H23DOSiNa
(MNa+) 332.1557, found 332.1559.
3-Hexyn -1-ol ter t-Bu tyld ip h en ylsilyl Eth er (10a ) a n d
4-(Tetr a h yd r ofu r a n -2-yl)-3-bu tyn -1-ol ter t-Bu tyld ip h en -
ylsilyl Eth er (10b). The reaction was carried out according
to the general procedure for the synthesis of the bis-sulfinyl
1
alkenes, but without Pd-catalyst. 10a : Yellow oil. H NMR δ
1.05 (s, 9H), 1.09 (t, J ) 7.5 Hz, 2H), 2.13 (qt, J ) 7.5, 2.4 Hz,
2H), 2.42 (tt, J ) 7.1, 2.4 Hz, 2H), 3.74 (t, J ) 7.1 Hz, 2H),
7.34-7.71 (m, 10H). 13C NMR δ 12.4, 14.2, 19.2, 22.9, 26.8 (3C),
62.9, 76.3, 82.8, 127.6 (4C), 129.6(2C), 133.8 (2C), 135.6 (4C).
IR 1589. MS (FAB) m/z 359 (MNa+). HRMS (FAB) calcd for
Meth yl (E)-5-ben zyloxy-3-(p-tolylsu lfin yl)-2-pen ten oate
1
(12g): Yellow oil. H NMR δ 2.31 (ddd, J ) 14.0, 7.5, 7.5 Hz,
1H), 2.31 (s, 3H), 3.09 (ddd, J ) 14.0, 7.0, 5.0 Hz, 1H), 3.32
(ddd, J ) 9.0, 7.5, 5.0, 1H), 3.42 (ddd, J ) 9.0, 7.5, 7.0 Hz,
1H), 3.67 (s, 3H), 4.35 (d, J ) 14.0 Hz, 1H), 4.38 (d, J ) 14.0
Hz, 1H), 6.75 (s, 1H), 7.18-7.28 (m, 7H), 7.45 (d, J ) 8.0 Hz,
2H). 13C NMR δ 21.5, 28.0, 51.8, 68.3, 72.8, 118.9, 126.5 (2C),
127.6 (2C), 128.3 (2C), 130.16 (2C), 130.18, 137.9, 138.1, 142.8,
162.8, 165.0. IR 1720, 1637, 1084. MS (FAB) m/z 359 (MH+).
HRMS (FAB) calcd for C20H23O4S (MH+) 359.1317, found
359.1316.
C
22H28OSiNa (MNa+) 359.1807, found 359.1803. 10b: Color-
1
less oil. H NMR δ 1.05 (s, 9H), 1.81-2.17 (m, 4H), 2.48 (td,
J ) 7.3, 1.8 Hz, 2H), 3.76 (t, J ) 7.3 Hz, 2H), 3.76 (m, 1H),
3.89-3.94 (m, 1H), 4.52-4.55 (m, 1H), 7.36-7.44 (m, 6H), 7.66-
7.68 (m, 4H). 13C NMR δ 19.2, 22.9, 25.4, 26.8 (3C), 33.4, 62.4,
67.7, 68.3, 81.1, 82.0, 127.7 (4C), 129.6 (2C), 133.6 (2C), 135.5
(4C). IR 2237. MS (FAB) m/z 379 (MH+). HRMS (FAB) calcd
for C24H31O2Si (MH+) 379.2093, found 379.2095.
Gen er al P r ocedu te for Su lfin ylzin cation of Alkyn oates.
Et2Zn (0.99 M in n-hexane) (0.31 mL, 0.307 mmol) was added
slowly to a solution of 1f (33.8 mg, 0.153 mmol), 11c (62.6 mg,
0.307 mmol), and Pd2(dba)3‚CHCl3 (3.2 mg, 0.00307 mmol) in
THF (0.15 mL) with stirring at -78 °C. After 15 min, the dry
ice bath was removed and the stirring was continued for 4 h.
The reaction was quenched with saturated NH4Cl and ex-
tracted with AcOEt. The organic layer was washed with brine
prior to drying and solvent evaporation. The residue was
chromatographed on silica gel with hexane-AcOEt (3:1) to give
12c (48.6 mg, 92%) as a yellow oil.
Meth yl (E)-6-ben zyloxy-3-(p-tolylsu lfin yl)-2-h exen oa te
(12h ): Yellow oil. 1H NMR δ 1.48-1.57 (m, 1H), 1.66 (m, 1H),
2.14 (ddd, J ) 14.0, 10.0, 4.5 Hz, 1H), 2.32 (s, 3H), 2.77 (ddd,
J ) 14.0, 10.0, 5.5 Hz, 1H), 3.33-3.40 (m, 2H), 3.69 (s, 3H),
4.37 (d, J ) 14.0 Hz, 1H), 4.39 (d, J ) 14.0 Hz, 1H), 6.71 (s,
1H), 7.17-7.29 (m, 7H), 7.44 (d, J ) 8.0 Hz, 2H). 13C NMR δ
21.5, 24.2, 28.9, 51.7, 69.2, 72.6, 117.7, 126.4 (2C), 127.5, 127.6
(2C), 128.3 (2C), 130.1 (2C), 138.2, 138.3, 142.8, 165.0, 165.8.
IR 1720, 1637, 1086. MS (FAB) m/z 373 (MH+). HRMS (FAB)
calcd for C21H25O4S (MH+) 373.1474, found 373.1474.
Meth yl (E)-4-ben zylth io-3-(p-tolylsu lfin yl)-2-bu ten oa te
(12i): Yellow oil. 1H NMR δ 2.39 (s, 3H), 2.72 (d, J ) 14.5 Hz,
1H), 3.72 (s, 2H), 3.74 (s, 3H), 4.38 (d, J ) 14.5 Hz, 1H), 6.82
(s, 1H), 7.24-7.47 (m, 9H). 13C NMR δ 21.5, 26.9, 36.6, 51.9,
118.8, 126.3 (2C), 127.3, 128.5 (2C), 129.0 (2C), 130.2 (2C),
137.1, 138.2, 142.9, 163.1, 164.9. IR 1720, 1105. MS (FAB) m/z
Meth yl (E)-3-(p-tolylsu lfin yl)p r op en oa te (12a ): Yellow
1
oil. H NMR δ 2.38 (s, 3H), 3.74 (s, 3H), 6.70 (d, J ) 14.6 Hz,
1H), 7.31 (d, J ) 7.9 Hz, 2H), 7.46 (d, J ) 14.6 Hz, 1H), 7.49
(d, J ) 7.9 Hz, 2H). 13C NMR δ 21.4, 52.2, 123.5, 125.0 (2C),
130.4 (2C), 138.3, 142.6, 151.5, 164.4. IR 1728, 1086. MS (FAB)
5556 J . Org. Chem., Vol. 68, No. 14, 2003

Pd-Catalyzed Sulfinylzincation
361 (MH+). HRMS (FAB) calcd for C19H21O3S2 (MH+) 361.0932,
found 361.0935.
(t. J ) 3.1 Hz, 1H), 2.05 (ddtd, J ) 13.4, 9.7, 6.4, 6.4 Hz, 1H),
2.32 (ddd, J ) 9.7, 6.4, 3.1 Hz, 2H), 2.84 (ddd, J ) 13.4, 9.7,
5.5 Hz, 1H), 3.29 (ddd, J ) 13.4, 9.7, 6.4 Hz, 1H), 3.76 (s, 3H),
4.53 (d, J ) 11.6 Hz, 1H), 4.60 (d, J ) 11.6 Hz, 1H), 4.81 (dd,
J ) 15.9, 2.4 Hz, 1H), 4.98 (dd, J ) 15.9, 1.8 Hz, 1H), 6.55
(dd, J ) 2.4, 1.8 Hz, 1H), 7.30-7.38 (m, 5H). 13C NMR δ 17.5,
21.0, 51.7, 51.9, 66.9, 69.7, 73.7, 82.5, 119.3, 127.9 (2C), 128.2,
128.6 (2C), 136.8, 162.7, 164.7. IR: 2118, 1716, 1092. MS (FAB)
m/z 321 (MH+). HRMS (FAB) calcd for C17H21O4S (MH+)
321.1160, found 321.1154.
Meth yl (E)-4-(N-ben zyl-N-m eth yla m in o)-3-(p-tolylsu l-
fin yl)-2-bu ten oa te (12j): Yellow oil. 1H NMR δ 2.03 (s, 3H),
2.38 (s, 3H), 2.88 (dd, J ) 15.0, 2.5 Hz, 1H), 3.20 (d, J ) 12.5
Hz, 1H), 3.72 (d, J ) 12.5 Hz, 1H), 3.78 (s, 3H), 4.20 (d, J )
15.0 Hz, 1H), 6.89 (d, J ) 2.5 Hz, 1H), 7.22-7.55 (m, 9H). 13C
NMR δ 21.5, 41.9, 51.9, 54.2, 61.5, 119.1, 126.2 (2C), 127.3,
128.3 (2C), 129.2 (2C), 129.9 (2C), 137.9, 139.5, 142.2, 165.3,
165.6. IR 1720, 1086. MS (FAB) m/z 358 (MH+). HRMS (FAB)
calcd for C20H24NO3S (MH+) 358.1477, found 358.1480.
Met h yl (E)-4-(5-Met h oxyca r b on yl-4-p en t yloxy)-3-(p -
tolylsu lfin yl)-2-bu ten oa te (14): Yellow oil. 1H NMR δ 1.79
(tt, J ) 6.7, 6.1 Hz, 2H), 2.35-2.39 (m, 2H), 2.40 (s, 3H), 3.36
(dt, J ) 9.2, 6.1 Hz, 1H), 3.49 (dt, J ) 9.2, 6.1 Hz, 1H), 3.77 (s,
3H), 3.78 (s, 3H), 4.02 (dd, J ) 14.6, 1.8 Hz, 1H), 5.01 (dd,
J ) 14.6, 1.8 Hz, 1H), 6.81 (t, J ) 1.8 Hz, 1H), 7.30 (d, J ) 7.9
Hz, 2H), 7.55 (d, J ) 7.9 Hz, 2H). 13C NMR δ 15.4, 21.5, 27.4,
52.0, 52.6, 66.1, 69.1, 73.3, 88.5, 118.3, 126.1 (2C), 130.1 (2C),
139.0, 142.6, 154.1, 163.6, 164.9. IR 2237, 1716, 1643, 1084.
MS (FAB) m/z 379 (MH+). HRMS (FAB) calcd for C19H23O6S
(MH+) 379.1215, found 379.1228
N,N-Dim et h yl (E)-4-b en zyloxy-3-(p -t olylsu lfin yl)-2-
1
bu ten a m id e (12q): Pale yellow oil. H NMR δ 2.39 (s, 3H),
2.98 (s, 3H), 3.12 (s, 3H), 3.98 (dd, J ) 14.3, 1.8 Hz, 1H), 4.31
(d, J ) 11.6 Hz, 1H), 4.46 (d, J ) 11.6 Hz, 1H), 4.86 (dd, J )
14.3, 1.2 Hz, 1H), 7.15 (dd, J ) 1.8, 1.2 Hz, 1H), 7.22-7.35
(m, 7H), 7.51 (d, J ) 8.5 Hz, 2H). 13C NMR δ 21.5, 35.1, 37.9,
65.9, 73.0, 120.7, 126.1 (2C), 127.8 (3C), 128.4 (2C), 130.0 (2C),
137.1, 138.9, 142.3, 156.5, 164.9. IR 1651, 1086. MS (FAB) m/z
358 (MH+). HRMS (FAB) calcd for C20H24NO3S (MH+) 358.1477,
found 358.1474.
(E)-4-Ben zyloxy-3-(p-tolylsu lfin yl)-2-bu ten on itr ile (12r ):
1
Yellow oil. H NMR δ 2.43 (s, 3H), 3.86 (d, J ) 14.0 Hz, 1H),
Meth yl (E)-4-ben zyloxy-3-[(p-m eth oxyp h en yl)su lfin yl]-
4.30 (d, J ) 11.6 Hz, 1H), 4.43-4.46 (m, 2H), 7.15 (s, 1H), 7.17-
7.42 (m, 9H). 13C NMR δ 21.5, 65.9, 73.3, 100.0, 114.1, 125.9
(2C), 128.1 (2C), 128.3, 128.6 (2C), 130.4 (2C), 136.2, 137.4,
143.4, 169.1. IR 2224, 1099. MS (FAB) m/z 312 (MH+). HRMS
(FAB) calcd for C18H18NO2S (MH+) 312.1058, found 312.1060.
1
2-bu ten oa te (12k ): Yellow oil. H NMR δ 3.76 (s, 3H), 3.83
(s, 3H), 4.05 (dd, J ) 15.3, 1.8 Hz, 1H), 4.32 (d, J ) 11.6 Hz,
1H), 4.49 (d, J ) 11.6 Hz, 1H), 5.09 (dd, J ) 15.3, 1.2 Hz, 1H),
6.83 (dd, J ) 1.8, 1.2 Hz, 1H), 6.91-6.94 (m, 2H), 7.22-7.24
(m, 2H), 7.29-7.36 (m, 3H), 7.53-7.56 (m, 2H). 13C NMR δ
52.0, 55.5, 65.7, 73.1, 114.8 (2C), 118.1, 127.9 (2C), 128.0, 128.2
(2C), 128.4 (2C), 133.1, 136.9, 162.4, 163.9, 164.9. IR 1716,
1087. MS (EI) m/z 361 (MH+). HRMS (EI) calcd for C19H21O5S
(MH+) 361.1110, found 361.1098.
Meth yl (Z)-4-(ter t-Bu tyldim eth ylsilyloxy)-3-(p-tolylth io)-
2-bu ten oa te (15). Following the same procedure for 5 from
1a , 11e (113 mg, 0.497 mmol) was converted into 15 (140 mg,
1
80%). Yellow oil. H NMR δ -0.07 (s, 6H), 0.82 (s, 9H), 2.37
(s, 3H), 3.76 (s, 3H), 3.90 (s, 2H), 6.21 (s, 1H), 7.12 (d, J ) 8.0
Hz, 2H), 7.42 (d, J ) 8.0 Hz, 2H). 13C NMR δ -5.6 (2C), 18.2,
21.2, 25.7 (3C), 51.2, 64.8, 109.2, 125.1, 129.8 (2C), 135.8 (2C),
139.9, 158.9, 167.0. IR 1708. MS (FAB) m/z 353 (MH+). HRMS
(FAB) calcd for C18H29O3SSi (MH+) 353.1606, found 353.1610.
Meth yl (E)-4-ben zyloxy-3-(p h en ylsu lfin yl)-2-bu ten oa te
1
(12l): Yellow oil. H NMR δ 3.76 (s, 3H), 4.07 (dd, J ) 15.3,
1.8 Hz, 1H), 4.34 (d, J ) 11.6 Hz, 1H), 4.50 (d, J ) 11.6 Hz,
1H), 5.12 (dd, J ) 15.3, 1.2 Hz, 1H), 6.84 (dd, J ) 1.8, 1.2 Hz,
1H), 7.23-7.65 (m, 10H). 13C NMR δ 52.0, 65.7, 73.1, 118.1,
126.0 (2C), 127.9 (2C), 128.0, 128.4 (2C), 129.3 (2C), 131.7,
136.9, 142.3, 163.9, 164.8. IR 1720, 1086. MS (FAB) m/z 331
(MH+). HRMS (FAB) calcd for C18H19O4S (MH+) 331.1011,
found 331.1004.
Met h yl (Z)-4-(ter t-b u t yld im et h ylsilyloxy)-3-(p -t olyl-
su lfin yl)-2-bu ten oa te [(Z)-12e]: Colorless oil. 1H NMR δ
-0.03 (s, 3H), 0.01 (s, 3H), 0.85 (s, 9H), 2.39 (s, 3H), 3.82 (s,
3H), 4.35 (dd, J ) 18.0, 2.2, Hz, 1H), 4.79 (dd, J ) 18.0, 2.2
Hz, 1H), 6.46 (t, J ) 2.2, Hz, 1H), 7.28 (d, J ) 8.3 Hz, 2H),
7.70 (d, J ) 8.3 Hz, 2H). 13C NMR δ -5.6, -5.5, 18.2, 21.3,
25.7 (3C), 52.2, 57.7, 119.7, 124.5 (2C), 129.9 (2C), 140.3, 141.3,
164.6, 165.2. IR 1716, 1047. MS (FAB) m/z 369 (MH+). HRMS
(FAB) calcd for C18H29O4SSi (MH+) 369.1556, found 369.1544.
Met h yl (E)-4-ben zyloxy-3-[(p -ch lor op h en yl)su lfin yl]-
1
2-bu ten oa te (12m ): Yellow oil. H NMR δ 3.76 (s, 3H), 4.14
(dd, J ) 15.3, 1.8 Hz, 1H), 4.35 (d, J ) 11.6 Hz, 1H), 4.52 (d,
J ) 11.6 Hz, 1H), 5.10 (dd, J ) 15.3, 1.2 Hz, 1H), 6.80 (dd,
J ) 1.8, 1.2 Hz, 1H), 7.24-7.26 (m, 2H), 7.31-7.41 (m, 5H),
7.55-7.57 (m, 2H). 13C NMR δ 52.1, 65.9, 73.3, 118.2, 127.4
(2C), 128.0 (2C), 128.2, 128.5 (2C), 129.5 (2C), 136.6, 137.9,
140.9, 163.7, 164.7. IR 1720, 1088. MS (FAB) m/z 365 (MH+).
HRMS (FAB) calcd for C18H18ClO4S (MH+) 365.0615, found
365.0606.
Met h yl (E)-2-Allyl-4-b en zyloxy-3-(p -t olylsu lfin yl)-2-
bu ten oa te (16). Et2Zn (1.01 M in n-hexane) (0.44 mL, 0.449
mmol) was added slowly to a stirred solution of 11c (91.7 mg,
0.449 mmol), 1f (49.4 mg, 0.224 mmol), and Pd2(dba)3‚CHCl3
(4.64 mg, 0.00449 mmol) in THF (0.22 mL) at -78 °C. After
15 min, the stirring was continued at room temperature for 5
h. Then, a solution of CuCN‚2LiCl [prepared by drying a
mixtute of CuCN (20.1 mg, 0.224 mmol) and LiCl (19.0 mg,
0.449 mmol) at 140 °C for 2 h in situ] in THF (0.22 mL) was
added to the mixture. After the addition of allyl bromide (58
µL, 0.673 mmol), the reaction mixture was stirred at 0 °C for
1 h. The reaction was quenched with saturated NH4Cl and
extracted with Et2O. The organic layer was washed with brine
prior to drying and solvent evaporation. The residue was
chromatographed on silica gel with hexane-AcOEt (5:1) to give
16 (64.1 mg, 74%) as a yellow oil. 1H NMR δ 2.40 (s, 3H), 3.63
(dd, J ) 15.8, 6.7 Hz, 1H), 3.64 (s, 3H), 3.72 (dd, J ) 15.8, 6.7
Hz, 1H), 4.17 (d, J ) 11.6 Hz, 1H), 4.18 (d, J ) 12.8, 1H), 4.22
(d, J ) 11.6 Hz, 1H), 4.28 (d, J ) 12.8, 1H), 5.19 (dd, J ) 10.4,
1.5 Hz, 1H), 5.21 (dd, J ) 17.1, 1.5 Hz, 1H), 5.85 (dddd, J )
17.1, 10.4, 6.7, 6.7 Hz, 1H), 7.12 (d, J ) 8.5 Hz, 2H), 7.21-
7.30 (m, 5H), 7.46 (d, J ) 8.5 Hz, 2H). 13C NMR δ 21.3, 34.8,
52.2, 61.1, 72.2, 118.4, 124.3 (2C), 127.4, 127.6 (2C), 128.1 (2C),
129.9 (2C), 132.7, 137.5, 138.2, 140.3, 141.2, 145.3, 167.5. IR
1732, 1051. MS (FAB) m/z 385 (MH+). HRMS (FAB) calcd for
Meth yl (E)-4-ben zyloxy-3-[(p-n itr op h en yl)su lfin yl]-2-
bu ten oa te (12n ): Yellow crystals. Mp 89.5-90.5 °C. 1H NMR
δ 3.77 (s, 3H), 4.26 (dd, J ) 15.6, 2.4 Hz, 1H), 4.40 (d, J )
11.6 Hz, 1H), 4.57 (d, J ) 11.6 Hz, 1H), 5.12 (dd, J ) 15.6, 1.8
Hz, 1H), 6.81 (dd, J ) 2.4, 1.8 Hz, 1H), 7.26-7.28 (m, 2H),
7.34-7.40 (m, 2H), 7.80-7.83 (m, 3H), 8.21-8.24 (m, 2H). 13
C
NMR δ 52.2, 66.0, 73.5, 118.6, 124.2 (2C), 126.8 (2C), 128.1
(2C), 128.4, 128.6 (2C), 136.3, 149.5, 149.9, 163.2, 164.4. IR
1720, 1525, 1091. MS (FAB) m/z 376 (MH+). HRMS (FAB)
calcd for C18H18NO6S (MH+) 376.0855, found 376.0851.
Meth yl (E)-4-ben zyloxy-3-m eth ylsu lfin yl-2-bu ten oa te
1
(12o): Colorless oil. H NMR δ 2.78 (s, 3H), 3.76 (s, 3H), 4.52
(d, J ) 11.8 Hz, 1H), 4.60 (d, J ) 11.8 Hz, 1H), 4.85 (dd, J )
15.8, 2.0 Hz, 1H), 4.98 (dd, J ) 15.8, 2.0 Hz, 1H), 6.61 (t, J )
2.0 Hz, 1H), 7.26-7.40 (m, 5H). 13C NMR δ 41.1, 52.0, 66.8,
73.8, 118.5, 127.9 (2C), 128.2, 128.6 (2C), 136.7, 164.5, 164.8.
IR 1720, 1078. MS (FAB) m/z 269 (MH+). HRMS (FAB) calcd
for C13H17O4S (MH+) 269.0848, found 269.0836.
Meth yl (E)-4-(ben zyloxy)-3-(4-p en tyn ylsu lfin yl)-2-bu -
ten oa te (12p ): Yellow oil. 1H NMR δ 1.81-1.91 (m, 1H), 1.93
C
22H25O4S (MH+) 385.1473, found 385.1459.
J . Org. Chem, Vol. 68, No. 14, 2003 5557

Maezaki et al.
Meth yl (E)-2-Ben zoyl-4-ben zyloxy-3-(p-tolylsu lfin yl)-
2-bu ten oa te (17). Following the same procedure described
for 16 but with the addition of benzoyl chloride (0.076 mL,
0.654 mmol), 11c (89.1 mg, 0.436 mmol) and 1f (48.0 mg, 0.218
1057. M/S (FAB) m/z 449 (MH+). HRMS (FAB) calcd for
C
26H25O5S (MH+) 449.1423, found 449.1439.
Su p p or tin g In for m a tion Ava ila ble: The plots of yield
1
mmol) were converted into 17 (61.1 mg, 62%). Yellow oil. H
vs equivalent of 1-alkynoate in sulfinylzication of 1-alkynoates;
experimental procedure and characterization data for com-
pounds 1b-d , 1f-m , 11f, 11g, 11i-l, and 13; 1H NMR spectra
of all new compounds. This material is available free of charge
via the Internet at http://pubs.acs.org.
NMR δ 2.40 (s, 3H), 3.63 (s, 3H), 4.28 (d, J ) 11.6 Hz, 1H),
4.31 (d, J ) 11.6 Hz, 1H), 4.35 (d, J ) 13.4 Hz, 1H), 4.66 (d,
J ) 13.4 Hz, 1H), 7.14 (d, J ) 6.7 Hz, 2H), 7.25-7.31 (m, 5H),
7.53 (t, J ) 7.6 Hz, 2H), 7.62-7.67 (m, 3H), 8.02 (d, J ) 7.3
Hz, 2H). 13C NMR δ 21.4, 52.9, 61.4, 72.8, 125.4 (2C), 127.6
(2C), 127.7, 128.2 (2C), 128.9 (2C), 129.3 (2C), 130.0 (2C), 134.2,
135.9, 137.2, 137.4, 138.0, 141.8, 155.9, 163.4, 191.1. IR 1728,
J O034108J
5558 J . Org. Chem., Vol. 68, No. 14, 2003