Three-Component 1,2-Carboalkynylation of Alkenes Via Cooperative Nickel/Photoredox Catalysis

A photoredox/nickel dual catalytic system was developed for the three-component 1,2-carboalkynylation of alkenes. This redox-neutral protocol enables the efficient and divergent synthesis of aliphatic alkynes in high yields with excellent regioselectivity, using readily available starting materials. The resulting adducts can be readily transformed into terminal alkynes, facilitating diverse downstream transformations. Mechanistic studies were performed to elucidate the preferred pathway of this alkene difunctionalization process.