Efficient Boron−Copper Additions to Aryl-Substituted Alkenes Promoted by NHC−Based Catalysts. Enantioselective Cu-Catalyzed Hydroboration Reactions

Yunmi Lee and Amir H. Hoveyda
J. Am. Chem. Soc., 2009, 131, 3160–3161
DOI:10.1021/ja809382c

Summary: This paper describes the development of a Cu-catalyzed formal hydroboration of olefinic substrates (styrene derivatives). The reaction is highly regio and stereoselective affording the organoboron products in moderate to high yield. The reaction utilizes a copper NHC complex (0.5-7.5 mol%) and pinacolatoboron as the boron source. In the asymmetic variant the er's range from 86/14 to 99/1.