The reactions of some α-halo-β-ketosulfones with hard and soft nucleophiles. A preparation of sulfinate esters

Abstract

The α-halo-β-ketosulfonyl functionality was attacked by ethanethiolate at the halogen which, in the presence of a proton source, usually resulted in reduction to the β-ketosulfone. A range of other soft nucleophiles did not react, whereas hard nucleophiles invariably attacked at the carbonyl, with subsequent cleavage to α-halosulfones. Ambident arylsulfinate anions usually attacked at halogen to form the sulfonyl halide, which reacted with excess sulfinate to give an intermediate that is readily attacked by alcohols. This reaction resulted in the formation of alkyl arylsulfinate esters in reasonable yields. The same reaction occurred when sulfonyl chlorides were reacted with sulfinate salts and it was rationalized by using HSAB principles. Spectral properties of some sulfinate esters are presented.