Photocatalytic Generation of π‐Allyltitanium Complexes via Radical Intermediates

Abstract

AbstractThe addition of π‐allylmetal complexes to carbonyls is the most important route to homoallylic alcohols. This study reports the first photocatalytic generation of π‐allyltitanium complexes by a radical strategy. This novel strategy enables the three‐component allylation of carbonyls with 1,3‐butadiene, providing rapid access to valuable homoallylic alcohols (over 60 examples). The exceptional regio‐ and diastereoselectivity provided by dual photoredox/Ti catalysis is comparable to that of the Cr‐catalyzed Nozaki–Hiyama–Kishi allylation reaction.