COMMUNICATIONS
different systems as well as of a catalytic process in zirconium
are currently in progress.
Experimental Section
A solution of n-butyllithium in hexanes (1.6m, 3.3 equiv) was added slowly
to a solution of bis(cyclopentadienyl)zirconium dichloride (1.5 equiv) in
dry THF at À788C. After the solution had been stirred for 1 h at À788C,
vinyl sulfide, sulfoxide, or sulfone was added (1 equiv) at À788C. The
reaction mixture was allowed to warm to room temperature and stirred for
2.5 5 h. The quantitative formation of the adduct 4 was checked by gas
chromatography. Then, the solution was cooled to À208C and the
electrophile was added. The reaction mixture was warmed to room
temperature and diluted with ether and 1n HCl. The aqueous phase was
then extracted three times with ether. The combined organic phases were
washed successively with a solution of saturated aqueous sodium hydrogen
carbonate, brine, and water (in case of addition of iodine, aqueous Na2S2O3
was also used), dried over MgSO4, and concentrated to dryness under
reduced pressure. The residue obtained was finally purified by column
chromatography on silica gel.
Scheme 4. Mechanistic rationalization of the isomerization and elimina-
tion in the reactions shown in Scheme 3.
MgBr, respectively (Scheme 4). Deuterolysis and hydrolysis
of 31 yielded 32 and its hydrogen analogue, respectively.
Decarbozirconation of 30 and 31 occurs with elimination of
the leaving group to give the corresponding vinylic organo-
metallic derivative 4, R Ph. This reaction seems to proceed
through skeletal rearrangement,[24] since the zirconacycle
intermediate disappears in favor of the vinyl transition metal
complex, which is obtained in very good yield. In this case,
whatever the stereochemistry of the starting olefin (as
described in Tables 1 and 2), the carbon heteroatom bond
of the metalated center C1 shifts to produce the most stable
intermediate (see 28 31 in Scheme 4). Such an isomerization
Received: November 2, 2001
Revised: January 21, 2002 [Z18150]
[1] For
a recent review, see a) A. F¸rstner, Active Metals, VCH,
Weinheim, 1996; b) E. Negishi, Organometallics in Organic Synthesis,
Wiley-Interscience, New York, 1980.
¬
[2] a) D. Guijarro, M. Yus, Tetrahedron Lett. 1994, 35, 2965; b) C. Najera,
M. Yus, Tetrahedron 1999, 55, 10547.
[3] a) P. D. Magnus, Tetrahedron 1977, 33, 2019; b) S. Patai, Z. Rappoport,
C. J. M. Stirling, The Chemistry of Sulphones and Sulphoxides, Wiley,
Chichester, 1988; c) N. S. Simpkins, Sulphones in Organic Synthesis,
Pergamon, Oxford, 1993.
[4] a) T. Cuvigny, C. Herve du Penhoat, M. Julia, Tetrahedron Lett. 1983,
24, 4311; b) M. Julia, H. Lauron, J.-P. Stacino, J.-N. Verpeaux, Y.
Jeannin, Y. Dromzee, Tetrahedron 1986, 42, 2475.
could be caused by an interaction between the sulfur moiety
1
and the zirconium atom,[25] which would weaken the C Zr
À
bond and facilitate the isomerization. Then, whatever the
[5] a) J.-L. Fabre, M. Julia, J.-N. Verpeaux, Bull. Soc. Chim. Fr. 1985, 762;
b) J.-L. Fabre, M. Julia, J.-N. Verpeaux, Bull. Soc. Chim. Fr. 1985, 7 7 2;
c) J. E. Baldwin, R. M. Adlington, Y. Ichikawa, C. J. Kneale, J. Chem.
Soc. Chem. Commun. 1988, 702.
stereochemistry of the starting material, a conformation is
1
À
always possible in which the C S bond is antiperiplanar to
2
3
À
the C
C
bond (see 28 31, Scheme 4). The elimination
reaction (or decarbozirconation) occurs in a concerted way to
give the vinyl zirconium compound.
[6] a) B. M. Trost, Bull. Chem. Soc. Jpn. 1988, 61, 107; b) J.-E. B‰ckvall, R.
¬
Chinchilla, C. Najera, M. Yus, Chem. Rev. 1998, 98, 2291.
[7] a) T. Cohen, M. D. Doubleday, J. Org. Chem. 1990, 55, 47 84; b) T.
Cohen, M. Bhupathy, Acc. Chem. Res. 1989, 22, 152.
[8] a) F. Foubelo, A. Gutierrez, M. Yus, Tetrahedron Lett. 1999, 40, 8173;
b) M. Yus, Chem. Soc. Rev. 1996, 155.
The stereochemistry of the vinyl zirconium complex can
then be rationalized by the zirconacyclopentane intermedi-
ates 29, 33, and 34. Indeed, in 29 the most stable isomer is
[9] a) C. Averbuj, J. Kaftanov, I. Marek, Synlett 1999, 11, 1939; b) J.
Kaftanov, N. Vais-Morlender, C. Averbuj, A. Liard, I. Marek,
Polyhedron 2000, 19, 563; c) N. Vais-Morlender, J. Kaftanov, I. Marek,
Synthesis 2000, 917; d) N. Vais-Morlender, N. Solodovnikova, I.
Marek, Chem. Commun. 2000, 1849.
[10] For reviews, see: a) E. Negishi, T. Takahashi, Bull. Chem. Soc. Jpn.
1998, 71, 755; b) E. Negishi, T. Takahashi, Acc. Chem. Res. 1994, 27,
124; c) E. Negishi, D. Y. Kondakov, Chem. Soc. Rev. 1996, 26, 417;
d) E. Negishi, Comprehensive Organic Synthesis, Vol. 5 (Eds.: B. M.
Trost, I. Fleming, L. A. Paquette), Pergamon, Oxford, 1991, p. 1163.
[11] a) T. Takahashi, M. Kotora, R. Fischer, Y. Nishihara, K. Nakajima, J.
Am. Chem. Soc. 1995, 117, 11039; b) J. Ichikawa, M. Fujiwara, H.
Nawata, T. Okauchi, T. Minami, Tetrahedron Lett. 1996, 37, 8799;
c) M. Fujiwara, J. Ichikawa, T. Okauchi, T. Minami, Tetrahedron Lett.
1999, 40, 7261.
[12] a) A. Liard, I. Marek, J. Org. Chem. 2000, 65, 7218; b) A. Liard, J.
Kaftanov, H. Chechik, S. Farhat, N. Morlender-Vais, C. Averbuj, I.
Marek, J. Organomet. Chem. 2001, 624, 26; c) B. Ganchegui, P. Bertus,
J. Szymoniak, Synlett 2001, 123.
[13] a) J. F. Normant, A. Alexakis, A. Commercon, G. Cahiez, J. Villieras,
C. R. Acad. Sci. 1974, 279, 763; b) J. F. Normant, A. Alexakis,
Synthesis 1981, 841.
expected to have an anti relationship between the octyl
substituent and the zirconium atom. When one more sub-
stituent is added in the b-position, as in 16, intermediate 33
leads to two isomeric vinyl zirconium derivatives in a 1:1 ratio
(see Table 2, entry 5). However, when 17 is treated with 1, 34
is expected to be the more stable zirconacycle as a result of the
steric interaction between the phenyl and the alkyl groups.[26]
In summary, we have developed an easy and general new
method for the conversion of vinyl sulfides, sulfoxides, and
sulfones into vinylic organozirconium derivatives with good
yields of isolated products. Our investigations of several
[14] P. Wipf, H. Jahn, Tetrahedron 1996, 52, 12853.
1412
¹ WILEY-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002
1433-7851/02/4108-1412 $ 20.00+.50/0
Angew. Chem. Int. Ed. 2002, 41, No. 8