Visible-Light-Promoted Nickel-Catalyzed Cross-Coupling of Alkyltitanium Alkoxides with Aryl and Alkenyl Halides.

Here, we report that alkyltitanium alkoxides generated in situ from Grignard reagents and Ti(O i Pr) 4 undergo a photocatalyst-free nickel-catalyzed cross-coupling with organic halides upon irradiation with blue light. Mechanistic studies suggested that the reaction proceeds through radical intermediates formed by photochemical decomposition of the alkyltitanium reagents. Various aryl, heteroaryl, and vinyl halides were efficiently alkylated under the reported conditions, including those containing ester and amide groups.