Some reactions of chloro(di-t-butyl)phosphine and of phenyl di-t-butylphosphinite

Abstract

Further evidence of the difficulty of nucleophilic attack on a phosphorus atom carrying two t-butyl groups is presented. Chloro(di-t-butyl)phosphine and benzyl chloride at 100° give the dichlorophosphorane, which is unaffected by methanolic sodium methoxide but which at 120° gives benzyl(chloro)-t-butylphosphine. Di-t-butylphosphine oxide, formed by hydrolysis of chloro(di-t-butyl)phosphine is stable in alkaline solution and does not add to carbonyl systems. With butyl-lithium and benzoyl chloride it gives benzoyldi-t-butylphosphine oxide. Quaternisation of phenyl di-t-butylphosphinite with alkyl halides gives di-t-butylphenoxyphosphonium salts, which are remarkably resistant to hydrolysis.