In Situ-Generated Chiral Co(I)-Catalyst for Asymmetric [2+2+2] Cycloadditions of Triynes

Abstract

The development of an in situ catalytic system based on cobalt(II)-salts, chiral P,N-ligands, and a reductant for the intramolecular asymmetric cyclization of triynes is described. This system represents the first chiral in situ-generated Co(I)-catalyst system for asymmetric [2+2+2] cycloadditions. The system consists only of commercially available components and leads to high yields and selectivities for the [2+2+2] cycloaddition of triynes in up to 16 examples.