Cobalt‐Catalyzed Difunctionalization of Styrenes via Ligand Relay Catalysis†

Comprehensive Summary Here, we report a cobalt‐catalyzed sequential dehydrogenative Heck silylation/hydroamination of styrenes with hydrosilane and diazo compound to access 1‐amino‐2‐silyl compounds with excellent regioselectivity. This difunctionalization reaction could undergo smoothly using 1 mol% catalyst loading with good functional group tolerance. Not only di‐ and tri‐substituted hydrosilanes, but also alkoxysilane is suitable, which does explore the scope of the family of 1‐amino‐2‐silyl compounds. The ligand relay phenomenon between neutral tridentate NNN ligand and anionic NNN ligand is observed for the first time via absorption spectral analysis in this one‐pot, two‐step transformations. The primary mechanism has been proposed based on the control experiments.