Stannous-modified cyanoborohydride

Abstract

The reducing properties of stannous-modified cyanoborohydride were examined to explore the synthetic utility of the reagent. Stannous-modified cyanoborohydride was prepared by the combination of 1.0 molar equiv of stannous chloride and 2.0 molar equiv of sodium cyanoborohydride. Stannous-modified cyanoborohydride in anhydrous diethyl ether reduced tertiary, allyl, and benzyl halides to corresponding hydrocarbons without attacking primary alkyl, secondary alkyl, and aryl halides. The reagent in diethyl ether reduced aldehydes and ketones to the corresponding alcohols. Furthermore, the reagent in methanol reduced enamines readily to the corresponding amines.