Radical Crotylation of Aldehydes with 1,3-Butadiene by Photoredox Cobalt and Titanium Dual Catalysis.

Metal-hydride hydrogen atom transfer (MHAT) has been recognized as a powerful method for alkene functionalization; however, photochemical MAT-mediated chemoselective functionalization of dienes remains undeveloped. In this study, we report a radical strategy (1e - ) through MHAT using photoredox cobalt and titanium dual catalysis for aldehyde crotylation with butadiene, achieving excellent regio- and diastereoselectivity.