General asymmetric hydrogenation of alpha-branched aromatic ketones catalyzed by TolBINAP/DMAPEN-ruthenium(II) complex

Org Lett. 2007 Mar 1;9(5):939-41. doi: 10.1021/ol070125+. Epub 2007 Jan 31.

Abstract

[reaction: see text] A catalyst system consisting of RuCl2[(S)-tolbinap][(R)-dmapen] and t-C4H9OK in 2-propanol effects asymmetric hydrogenation of arylglyoxal dialkylacetals to give the alpha-hydroxy acetals in up to 98% ee. Hydrogenation of racemic alpha-amidopropiophenones under dynamic kinetic resolution predominantly gives the syn alcohols in up to 99% ee and >98% de, while the reaction of racemic bezoin methyl ether gives the anti alcohols in excellent stereoselectivity.