title: Synthetic scope of Ru(OH)x/Al2O3-catalyzed hydrogen-transfer reactions: an application to reduction of allylic alcohols by a sequential process of isomerization/Meerwein-Ponndorf-Verley-type reduction.
abstract: Reduction of allylic alcohols can be promoted efficiently by the supported ruthenium catalyst Ru(OH)x/Al2O3. Various allylic alcohols were converted to saturated alcohols in excellent yields by using 2-propanol without any additives. This Ru(OH)x/Al2O3-catalyzed reduction of a dienol proceeds only at the allylic double bond to afford the corresponding enol, and chemoselective isomerization and reduction can be realized under similar conditions. The catalysis is truly heterogeneous and the high catalytic performance can be maintained during at least three recycles of the Ru(OH)x/Al2O3 catalyst. The transformation of allylic alcohols to saturated alcohols consists of three sequential reactions: oxidation of allylic alcohols to alpha,beta-unsaturated carbonyl compounds; reduction of alpha,beta-unsaturated carbonyl compounds to saturated carbonyl compounds; and reduction of saturated carbonyl compounds to saturated alcohols.
authors.affiliation: Department of Applied Chemistry, School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Jung Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Takeshi
authors.initials: T
authors.lastname: Koike
authors.forename: Miyuki
authors.initials: M
authors.lastname: Kotani
authors.forename: Kazuya
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Noritaka
authors.initials: N
authors.lastname: Mizuno