[32501-93-2]  · C11H14O2SSi  · 1-Phenylsulfonyl-2-(trimethylsilyl)acetylene  · (MW 238.41)

(reagent for preparation of a-vinyl carbonyls, and for use in cycloadditions and preparation of cis- and trans-vinyl sulfones)

Physical Data: mp 68-70 °C.

Solubility: sol most organic solvents.

Form Supplied in: colorless hygroscopic crystals.

Handling, Storage, and Precautions: very sensitive to alkaline or acidic conditions.

Addition Reactions.

Enolates of 1,3-dicarbonyl compounds add smoothly to the title reagent (1) to provide mainly the cis-vinyl sulfones (2). These are reduced by treatment with Aluminum Amalgam to give vinyl ketones (3) (eq 1).2 Similarly, addition of organocuprates leads to the cis-vinyl sulfones (4) (eq 2).1

Reduction of (1) with hydrogen and palladium in pyridine gives the cis-vinyl sulfone, while in the absence of pyridine the trans isomer is obtained.3 These products may also be obtained by reduction with Diisobutylaluminum Hydride, giving the trans isomer, or treatment with Bis(1,5-cyclooctadiene)nickel(0) to produce the cis isomer.1 These vinyl sulfones have been used as acetylene equivalents in a variety of organometallic addition reactions, as well as in cycloaddition reactions.1,3,4

Cycloaddition Reactions.

Cycloaddition of (1) with 1-Methoxy-3-trimethylsilyloxy-1,3-butadiene (Danishefsky's diene) (5) has been reported to yield the phenol (6) (eq 3), which may be further elaborated to a variety of products.5 (1) has also been used in reactions with azide (7) to produce the triazole (8) (eq 4).6

Related Reagents.

Ethyl b-Phenylsulfonylpropiolate; Ethynyl p-Tolyl Sulfone.

1. Eisch, J. J.; Behrooz, M.; Dua, S. K. JOM 1985, 285, 121.
2. (a) Ohnuma, T.; Hata, N.; Fujiwara, H.; Ban, Y. JOC 1982, 47, 4713. (b) Ohnuma, T.; Hata, N.; Miyachi, N.; Wakamatsu, T.; Ban, Y. TL 1986, 27, 219. (c) Sawada, S.; Nakayama, T.; Esaki, N.; Tanaka, H.; Soda, K.; Hill, R. K. JOC 1986, 51, 3384.
3. Paquette, L. A.; Williams, R. V. TL 1981, 22, 4643.
4. Carr, R. V.; Williams, R. V.; Paquette, L. A. JOC 1983, 48, 4976.
5. Kloek, J. A. JOC 1981, 46, 1951.
6. Habich, D.; Barth, W. H 1989, 29, 2083.

Paul M. Herrinton

The Upjohn Company, Kalamazoo, MI, USA

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