Visible-light-promoted regioselective hydrocarboxylation of allenes with formate salt and CO.

Visible-light-promoted hydrocarboxylation of allenes with formate salt and CO was developed for the first time using commercially available [Ir(ppy)(dtbbpy)]PF as a photocatalyst. This strategy provides an efficient and practical method to access β,γ-unsaturated linear carboxylic acids in moderate yields with complete regioselectivity.

Photoredox-Catalyzed Phosphonocarboxylation of Allenes with Phosphine Oxides and CO.

Phosphonocarboxylation of allenes with diarylphosphine oxides and CO via visible-light photoredox catalysis was developed for the first time. This work provided practical and sustainable access to highly valuable but otherwise difficult-to-access linear allylic β-phosphonyl carboxylic acids in moderate yields with exclusive regio- and stereoselectivity. This method was also characterized by step and atom economy and transition-metal free and mild conditions.