title: A phosphetane catalyzes deoxygenative condensation of α-keto esters and carboxylic acids via P(III)/P(V)═O redox cycling.
abstract: A small-ring phosphacycle is found to catalyze the deoxygenative condensation of α-keto esters and carboxylic acids. The reaction provides a chemoselective catalytic synthesis of α-acyloxy ester products with good functional group compatibility. Based on both stoichiometric and catalytic mechanistic experiments, the reaction is proposed to proceed via catalytic P(III)/P(V)═O cycling. The importance of ring strain in the phosphacyclic catalyst is substantiated by an observed temperature-dependent product selectivity effect. The results point to an inherent distinction in design criteria for organophosphorus-based catalysts operating via P(III)/P(V)═O redox cycling as opposed to Lewis base (nucleophilic) catalysis.
authors.affiliation: Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Patrick K
authors.initials: PK
authors.lastname: Yan
authors.forename: Alexander T
authors.initials: AT
authors.lastname: Radosevich