title: Biphilic Organophosphorus Catalysis: Regioselective Reductive Transposition of Allylic Bromides via P(III)/P(V) Redox Cycling.
abstract: We report that a regioselective reductive transposition of primary allylic bromides is catalyzed by a biphilic organophosphorus (phosphetane) catalyst. Spectroscopic evidence supports the formation of a pentacoordinate (σ(5)-P) hydridophosphorane as a key reactive intermediate. Kinetics experiments and computational modeling are consistent with a unimolecular decomposition of the σ(5)-P hydridophosphorane via a concerted cyclic transition structure that delivers the observed allylic transposition and completes a novel P(III)/P(V) redox catalytic cycle. These results broaden the growing repertoire of reactions catalyzed within the P(III)/P(V) redox couple and suggest additional opportunities for organophosphorus catalysis in a biphilic mode.
authors: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
authors: Kyle D
authors: KD
authors: Reichl
authors: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
authors: Nicole L
authors: NL
authors: Dunn
authors: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
authors: Nicholas J
authors: NJ
authors: Fastuca
authors: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
authors: Alexander T
authors: AT
authors: Radosevich
mesh_terms: D000498:Allyl Compounds / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry*; D002384:Catalysis; D009943:Organophosphorus Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010758:Phosphorus / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000498:Allyl Compounds; D001965:Bromides; D009943:Organophosphorus Compounds; D010758:Phosphorus; C050431:allyl bromide