Regioselective Nucleophilic Alkylation/Arylation of B-H Bonds in o-Carboranes: An Alternative Method for Selective Cage Boron Functionalization

Article abstract of DOI:10.1021/jacs.8b10270

A new protocol for regioselective nucleophilic cage B-H substitution in o-carboranes has been proposed that is complementary to the strategies of transition metal catalysis and electrophilic substitution. Magnesium-mediated site-selective nucleophilic cage B(3,6)-H and B(9)-H substitution reactions of o-carboranes give a series of B(3,6)-dialkylated and B(9)-alkylated/arylated o-carboranes in high yields. Both steric and electronic factors of cage C substituents play crucial roles in controlling the site selectivity.