Rhodium(III)-catalyzed asymmetric carboboration of heterobicyclic alkenes

The transition-metal-catalyzed carboboration of heterobicyclic alkenes has been already established, however, the asymmetric version has never been uncovered. Herein, we describe a Rh(III)-catalyzed asymmetric carboboration of heterobicyclic alkenes, including 7-oxa- and 7-azabenzonorbornadienes, via borylative dimerization. During the transformation, another heterobicyclic alkene acts as electrophilic carbon reagent. The carboboration product bearing seven chiral centers could be efficiently obtained with good to high yields (70-98%) and excellent enantioselectivities (98->99% ee). Moreover, several transformations of the carboboration product were also presented. (C) 2020 Elsevier Ltd. All rights reserved.