ALKALINE HYDROLYSIS OF β-AND γ-FUNCTIONAL PHOSPHONIUM SALTS

Abstract

A model study of alkaline hydrolysis of β-and γ-heterosubstituted phosphonium salts has been made and used as a synthetic method to obtain diphosphine dioxides affording additional coordination sites in an alkyl chain linked to phosphorus. After synthesis of the corresponding salts, anomalous fragmentations, such as inversion in cleavage selectivity or participation of the reaction solvent, have been pointed out in alkaline hydrolysis of β-functional phosphonium salts. A mechanism is suggested to account for the presence of all compounds detected. In the case of γ-functional phosphonium salts, the alkaline hydrolysis leads only to predicted compounds corresponding to the usual selective cleavage of one phenyl group. The results observed have been used to synthesize symmetric and asymmetric diphosphine dioxides with ether substituted side chains.

Key Words:

• Phosphonium salt
• phosphine oxide
• diphosphine dioxides
• alkaline hydrolysis
• cleavage
• mechanism