Nickel-Catalyzed Intramolecular Hydrosilylation of Alkynes: Embracing Conventional and Electrochemical Routes

Abstract

Nickel-catalyzed intramolecular hydrosilylation can be efficiently achieved with high regio- and stereoselectivities through two distinct methodologies. The first approach utilizes a conventional method, involving the reduction of nickel salt (NiBr₂-2,2'-bipyridine) using manganese metal. The second method employs a one-step electrochemical reaction, utilizing the sacrificial anode process and NiBr₂bipy catalysis. Both methods yield silylated heterocycles in good to high yields through a syn-exo-dig cyclization process. Control experiments and molecular electrochemistry (cyclic voltammetry) provided further insights into the reaction mechanism.

Keywords: Cyclization; Electrosynthesis; Hydrosilylation; Nickel catalysis; and Silylated heterocycles.