Substitution and Addition Reactions of a (Methylene)phosphine with Alkyllithium Reagents

摘要

Treatment of the (methylene)phosphine (Me3Si)2NP=CHSiMe3 (1) with alkyllithium reagents and Me3SiCl affords either the diphosphinomethane derivative R2P-CH(SiMe3)-P(R)CH(SiMe3)2 (2, R = Me) or the trialkylphosphine R2PCH(SiMe3)2 (3, R = t-Bu). A reaction pathway involving both nucleophilic substitution and addition reactions at the P=C moiety is suggested. Compound 2 exhibits hindered rotation about the P-CH(SiMe3)2 bond with a measured delta G+ sub c of 17.7 kcal/mole. (Author)