A convenient and stereoselective synthesis of (E)-vinylseleno zirconocenes and (E)-vinylic selenol esters

Article abstract of DOI:10.1055/s-1999-2698

The insertion of elemental selenium into the Csp²-Zr bond of alkenylchlorozirconocenes affords (E)-vinylseleno zirconocenes, which were trapped by acyl chlorides giving (E)-vinylic selenol esters in good yields.

Full text of DOI:10.1055/s-1999-2698

LETTER
569
A Convenient and Stereoselective Synthesis of (E)-Vinylseleno Zirconocenes
and (E)-Vinylic Selenol Esters
Xian Huang*, Jun-Hua Wang
Department of Chemistry, Zhejiang University(Campus Xixi), Hangzhou, 310028, P.R.China
Fax and telephone: (+86)0571-8807077; E-mail: huangx.@public.hz.zj.cn
Received 11 January 1999
stirred for 4 hours. The solvent was removed under re-
Abstract: The insertion of elemental selenium into the Csp2-Zr
duced pressure, and the product was extracted from the
bond of alkenylchlorozirconocenes affords (E)-vinylseleno zir-
residue with diethyl ether (4 x 10ml), filtered, concentrat-
conocenes, which were trapped by acyl chlorides giving (E)-vinylic
ed under reduced pressure and further purified by flash
chromatography on silica gel (light petroleum ether-dieth-
yl ether (10:1) as the eluent), affording the product 3a.
selenol esters in good yields.
Key words: hydrozirconation, vinylseleno zirconocenes, vinylic
selenol esters
The outcomes were summarized in Table 1.
Recently transition metal selenolates have been widely
used in synthesis of selenides due to their good nucleo-
philicity in aprotic solvents.1 The following intermediates
have been reported: ArSeZnCl,1 ArSeCu,2 ArSeSmI2,3
Cp2TiSeAr,4 Cp2Zr(SeMe)2,5 Cp2Hf(SeMe)2,5 and
Cp2ZrSe2C6H4-o6 and they have complemented in reactiv-
ity the known main group metal selenolates, such as Ar-
SeNa,7 Me2AlSeMe,8 ArSeTl.9 Vinylic selenolates are
important intermediates for vinylic selenides, whose
promising potential could be anticipated by the combina-
tion of the special reactivity of selenium and particularly
reactivity associated with the carbon-carbon double
bond.10 Herein we report the first example of vinylseleno
transition metal complexes, and its application in facile
synthesis of (E)-vinylic selenol esters. Although vinylic
bromomagnesium selenolate11 and vinylic lithium
selenolate12 have been reported, it is safe to say that
vinylseleno transition metal complexes will complement
in reactivity the main group metal selenolates.
Table 1. Synthesis of (E)-vinylic selenol esters from alkynes, elemen-
tal selenium and acyl chlorides.
Scheme 1
Typical procedure: To the stirred suspension of 1.2 mmol
Cp2Zr(H)Cl13 in 8 ml THF (freshly distilled from sodium
and benzophenone) under N2 atmosphere was added drop-
wise 1mmol phenylacetylene through a syringe. The mix-
ture was stirred until it turned into a clear solution, then
was added dropwise by a syringe into the stirred suspen-
sion of 1.2 mmol selenium powder in 2 ml THF(disposed
as above), the mixture turned gradually from a dark yel-
low-green suspension into a deep red solution during 0.5
hours. Then 1 mmol CH3COCl was added dropwise
through a syringe, and the mixture was continued to be
It is noteworthy that in our experiments the insertion of el-
emental selenium into Csp2-Zr bond proceeds smoothly in
THF at room temperature(about 10 °C) and usually com-
pletes in 30min., while Gautheron B. et al reported similar
reactions between Se and t-Bu-zirconocene dimethyl or
diphenyl in boiling heptane for several hours.5,6
Synlett 1999, No. 5, 569–570 ISSN 0936-5214 © Thieme Stuttgart · New York

570
X. Huang, J.-H. Wang
LETTER
Selenol esters14 are synthetically useful compounds as
precursors of acyl radicals and acyl cations. They can also
be easily converted into the corresponding acids, esters,
amides, ketones, aldehydes, and alkenyl selenides.15 In
particular, vinylic selenol esters are very versatile seleni-
um derivatives which can serve as good electron acceptors
to generate cleanly vinylic selenide anions under mild
conditions12a and other applications.12b However, accord-
ing to our knowledge, the only reported synthetic method
of vinylic selenol esters involved demethylation of vinylic
methyl selenides with excessive MeSeLi under severe
conditions or sodium in DMA, followed by carbonylation
of the produced vinylic selenide anions.12 In comparison,
our method is more attractive. It should be pointed out that
apart from the 1-alkynes employed in Scheme 1, various
internal alkynes, alkenes, functionalized alkynes and alk-
enes can proceed hydrozirconation reaction smoothly and
stereoselectively,16 moreover, all the reagents in Scheme
1 are commercially available, as a result, the present
method has provided a versatile, convenient route to vari-
ous selenol esters other than (E)-vinylic selenol esters.
(7) Sharpless, K. B.; Lauer, R. F.; Teranishi, A. Y. J. Am. Chem.
Soc. 1973, 95, 6137.
(8) Kozikowski, A. P.; Ames, A. J. Org. Chem. 1978, 43, 2735.
(9) Detty, M. R.; Wood, G. P. J. Org.Chem. 1980, 45, 80.
(10) (a)Comasseto, J. V. J. Organomet. Chem. 1983, 253, 131.
(b) Comasseto, J. V.; Ling, L. W.; Petragnani, N.; Stefani. H.
A. Synthesis 1997, 373.
(11) Wudl, F.; Nalewajek, D. J. Organomet. Chem. 1981, 217, 329.
(12) (a)Testaferri, L.; Tiecco, M.; Tingoli, M.; Chianelli, D.
Tetrahedron 1986, 42, 4577. (b)Testaferri, L.; Tiecco, M.;
Tingoli, M.; Chianelli, D. Tetrahedron 1986, 42, 63.
(13) Buchwald, S. L.; LaMaire, S. J.; Nielsen, R. B.; Watson, B. T.;
King, S. M. Tetrahedron Lett. 1987, 28, 3895.
(14) Recent reviews: (a)Ogawa, A.; Sonoda, N. in Comprehensive
Organic Synthesis; Trost, B. M. and Fleming, I. Ed.;
Pergamon: Oxford, 1991; Vol.6, p461-484. (b) Ogawa, A.;
Sonoda, N. in Comprehensive Organic Functional
Transformations; Katritzky, A. R.; Meth-Cohn, O.; Rees, C.
W. Ed.; Pergamon: Oxford, 1995; Vol.5, p231-255.
(15) See the references cited in Maeda, H.; Nishiyama, A.; Kambe,
N.; Sonoda, N.; Fujiwara, S.; Shin-ike, T. Synthesis 1997, 342.
(16) Reviews: (a)Schwartz, J.; Labinger, J. A. Angew. Chem. Int.
Ed. Engl. 1976, 15, 333. (b)Labinger, J. A. in Comprehensive
Organic Synthesis; Trost, B. M. and Fleming, I. Ed.;
Pergamon: Oxford, 1991; Vol.8; p667. (c)Wipf, P.; Jahn, H.
Tetrahedron 1996, 52, 12853. (d)Negishi, E.; Takahashi, T.
Synthesis 1988, 1. (e)Negishi, E.; Takahashi, T. Aldrich Acta
1985, 18, 31.
(17) Physical and spectroscopic data of (E)-3-(benzotriazol-1-yl)
propenyl acetyl selenide(3d): yellowish solid, mp 69-70 °C
(uncorrected). 1H NMR(CCl4, Hexamethyldisilane as the
internal standard): d8.06-7.93(m, 1H), 7.62-7.13(m, 3H),
6.93(d, 1H, J = 15.6Hz), 6.03(dt, 1H, J = 15.6 and 6.0Hz),
5.24(d, 2H, J = 6.0Hz), 2.30(s, 3H). IR(KBr) n[cm-1]:
1736(C = O), 1358, 1320, 1268, 1236, 1164, 1108, 976, 946,
738, 576. MS(m/z):282(m++1, 80Se). Anal. Calcd. for
C11H11N3OSe: C%, 46.98; H%, 3.91; N%, 15.00.
Acknowledgement
Projects 29672008 and 29772007 are supported by National Natural
Science Foundation of China.
References and Notes
(1) Huang, X.; Xu, X. Synth. Commun. 1998, 28, 807 and
references therein.
(2) Osuka, A.; Ohmasa, N.; Suzuki, H. Synthesis 1982, 857.
(3) Fukuzawa, S. I.; Nimoto, Y.; Fujinami, T.; Sakai, S.
Heteroatom. Chem. 1990, 49.
Found: C%, 47.18; H%, 3.59; N%, 15.11.
(4) Xu, X.; Huang, X. Synth. Commun. 1997, 27, 3797.
(5) Gautheron, B.; Tainturier, G.; Meunier, P. J. Organomet.
Chem. 1981, 209, C49.
Article Identifier:
(6) Gautheron, B.; Tainturier, G.; Pouly, S.; Theobald, F.; Vivier,
H.; Laarif, A. Organometallics 1984, 3, 1495.
1437-2096,E;1999,0,05,0569,0570,ftx,en;Y20098ST.pdf
Synlett 1999, No. 5, 569–570 ISSN 0936-5214 © Thieme Stuttgart · New York