Deoxygenative 1,3-carbophosphination of allylic alcohols enabled by manganese pincer catalyst

Abstract

Organophosphines are versatile compounds with widespread applications in both organic synthesis and the development of biologically active molecules. Herein, we describe a manganese-catalyzed three-component deoxygenative 1,3-carbophosphination of allylic alcohols with alcohols and phosphines using a borrowing hydrogen strategy. This novel multi-component process offers a direct approach to synthesizing a diverse library of valuable ε-hydroxy phosphines in moderate to good yields. The method demonstrates a broad substrate scope and good functional group tolerance. The synthetic versatility of distal hydroxyphosphine compounds is showcased through downstream transformations, leading to a wide range of ε-functionalized phosphines. Mechanistic studies suggest a rate-determining step in the manganese-catalyzed dehydrogenation of secondary alcohols and a rapid Michael addition of α,β-unsaturated carbonyl by phosphines.