Chiral boronate derivatives via catalytic enantioselective conjugate addition of Grignard reagents on 3-boronyl unsaturated esters and thioesters.
There is a growing interest in the development of new methods to prepare chiral organoboronate derivatives in optically pure form. An efficient copper-catalyzed enantioselective conjugate addition methodology using Grignard reagents and 3-boronyl acrylate derivatives was optimized for the preparation of chiral alkylboronate products in high yields and up to 98% ee. The resulting 1,8-diaminonaphthalene adducts can be transformed into the corresponding boronic acid, pinacol boronate, and trifluoroborate salt. This method extends the realm of chemical reactions compatible with useful boron-containing substrates.
Lee
Jack Chang Hung
JC
Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada.
Hall
Dennis G
DG