Lithium tert-Butoxide-catalyzed Hydroboration of Carbonyl Compounds

We report the successful hydroboration of aldehydes and ketones with pinacolborane using 1 mol % lithium tert-butoxide under ambient conditions. The present protocol was applicable to various aldehydes and ketones, and the corresponding boronate esters and subsequent alcohols were obtained in good to excellent yields. In addition, this high-yielding practical method could be extended to the reduction of ester groups. Under optimized conditions, (LiOBu)-Bu-t facilitate the hydroboration of ester groups quantitatively.