Asymmetric hydrogenation and transfer hydrogenation of diketones

Asymmetric hydrogenation and transfer hydrogenation of ketones are efficient and direct methods allowing access to enantiomerically enriched secondary alcohols, and have been widely studied and applied in both academia and industry. While the asymmetric (transfer) hydrogenation of ketones having one carbonyl group has been extensively investigated, the related study on ketones bearing multiple carbonyl groups such as diketones is still relatively underdeveloped. Due to the challenge of regioselectivity control raised by multiple reactive sites, and the difficulty of stereoselectivity control caused by several potential coordination groups, multiple carbonyl substrates are more difficult to be hydrogenated in a highly regio- and stereoselective manner. Nonetheless, significant progress has been achieved in the past several decades. This review summarizes the related investigations and illustrates the influences of catalysts, substrates, temperatures, solvents, and reaction times on the regio- and stereoselectivities of the reactions.