Dual Photoredox- and Titanium Catalysis-Enabled Three-Component Radical Propargylation of Aldehydes with 1,3-Enynes.

Herein, a straightforward and practical strategy involving radicals for the three-component carbonyl propargylation via dual photoredox and titanium catalysis is presented. This strategy delivers homopropargyl alcohols and includes readily available starting materials, a broad substrate scope, high functional group tolerance, and mild reaction conditions. Catalytic Cp2TiCl2, recognized as an inexpensive, nontoxic, and bench-stable titanium source, is employed.