title: A well-defined monomeric aluminum complex as an efficient and general catalyst in the Meerwein-Ponndorf-Verley reduction.
abstract: The metal-catalyzed Meerwein-Ponndorf-Verley (MPV) reduction allows for the mild and sustainable reduction of aldehydes and ketones but has not found widespread application in organic synthesis due to the high catalyst loading often required to obtain satisfactory yields of the reduced product. We report here on the synthesis and structure of a sterically extremely overloaded siloxide-supported aluminum isopropoxide capable of catalytically reducing a wide range of aldehydes and ketones (52 examples) in excellent yields under mild conditions and with low catalyst loadings. The unseen activity of the developed catalyst system in MPV reductions is due to its unique monomeric nature and the neutral donor isopropanol weakly coordinating to the aluminum center. The present work implies that monomeric aluminum alkoxide catalysts may be attractive alternatives to transition-metal-based systems for the selective reduction of aldehydes and ketones to primary and secondary alcohols.
authors.affiliation: Department of Chemistry and Biochemistry, Texas Tech University, Box 1061, Lubbock, Texas, 79409-1061 (USA).
authors.forename: Brian
authors.initials: B
authors.lastname: McNerney
authors.forename: Bruce
authors.initials: B
authors.lastname: Whittlesey
authors.forename: David B
authors.initials: DB
authors.lastname: Cordes
authors.forename: Clemens
authors.initials: C
authors.lastname: Krempner
keywords: MPV reduction; aldehydes; aluminum; ketones; siloxide