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

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.