Regioselective Hydroboration and Hydrosilylation of N-Heteroarenes Catalyzed by a Zinc Alkyl Complex

Readily available zinc alkyl complexes showed good activity and regioselectivity in catalyzing hydroboration and hydrosilylation of N-heteroarenes. Hydroboration of benzo-fused N-heterocycles gave exclusive 1,2-addition products in 80-97% yields. Reactions of pyridines afforded a mixture of 1,2-, 1,4-, and 1,6-products in yields of 55-95%, with 1,2-dihydropyridine as the main product. Bis-hydrosilylation was observed for quinoline derivatives, generating bis-1,2-hydrosilylation products in 76-96% yields. Kinetic studies and control experiments were conducted to gain some insights into the reaction mechanism.