Photocatalytic Generation of π-allyltitanium Complexes via Radical Intermediates

The addition of pi-allylmetal complexes to carbonyls is the most important route to homoallylic alcohols. This study reports the first photocatalytic generation of pi-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.

Automated summary

This study reports a novel photocatalytic strategy for the generation of pi-allyltitanium complexes, allowing for the rapid access to valuable homoallylic alcohols through a three-component allylation reaction with 1,3-butadiene and carbonyls. The exceptional regio- and diastereoselectivity provided by dual photoredox/Ti catalysis is comparable to that of the Cr-catalyzed Nozaki-Hiyama-Kishi allylation reaction.