Mitsunobu Reactions Catalytic in Phosphine and a Fully Catalytic System.
The Mitsunobu reaction is renowned for its mild reaction conditions and broad substrate tolerance, but has limited utility in process chemistry and industrial applications due to poor atom economy and the generation of stoichiometric phosphine oxide and hydrazine by-products that complicate purification. A catalytic Mitsunobu reaction using innocuous reagents to recycle these by-products would overcome both of these shortcomings. Herein we report a protocol that is catalytic in phosphine (1-phenylphospholane) employing phenylsilane to recycle the catalyst. Integration of this phosphine catalytic cycle with Taniguchi's azocarboxylate catalytic system provided the first fully catalytic Mitsunobu reaction.
Department of Medicinal Chemistry, University of Minnesota, 308 Harvard St. SE, Minneapolis, MN 55455 (USA).
Joseph A
JA
Buonomo
Department of Medicinal Chemistry, University of Minnesota, 308 Harvard St. SE, Minneapolis, MN 55455 (USA). aldri015@umn.edu.
Courtney C
CC
Aldrich
D000438:Alcohols / Q000737:chemistry*; D002384:Catalysis; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010720:Phosphines / Q000737:chemistry*
D000438:Alcohols; D004952:Esters; D010720:Phosphines; C044646:phosphine
organocatalysis; phosphorus heterocycles; reaction kinetics; silanes; synthetic methods