Selective reduction of carbonyl groups with systems composed of (η5-C5H5)2MoH2and protonic acids: new highly regio- and diastereo-selective reduction of ketones

Abstract
The system consisting of (η5-C5H5)2MoH2 and protonic acids such as RCO2H, HCl, and p-McC6H4SO3H reduced aldehydes and ketones under mild conditions chemoselectively; an extremely high diastereoselectivity was achieved by using the reaction intermediate (η5-C5H5)2Mo(H)OSO2C6H4Me-p in the reduction of 4-t-butylcyclohexanone.