Ligand-controlled regiodivergence in cobalt-catalyzed hydrosilylation of isoprene†

In this article, we disclose a method for the regiodivergent and stereoselective hydrosilylation of isoprene using an Earth-abundant cobalt catalyst via variation of ligands. With a less sterically hindered bidentate ligand, the reactions proceeded through 4,1-hydrosilylation to afford allylsilanes in excellent regio- and stereoselectivities. By switching to a bulkier ligand, the reactions were efficiently diverted to 2,1-addition products for the first time. This regiodivergent protocol provides a modular approach for the construction of structurally diverse organosilanes with high atom economy and without the formation of stoichiometric byproducts.