Photoinduced Palladium-Catalyzed Dicarbofunctionalization of Terminal Alkynes

Herein, a conceptually distinct approach was developed that allowed for the dicarbofunctionalization of alkynes at room temperature using simple, bench-stable alkyl iodides and a second molecule of alkyne as coupling partner. Specifically, the photochemical activation of palladium complexes enabled this strategic dicarbofunctionalization via addition of alkyl radicals from secondary and tertiary alkyl iodides and formation of an intermediate palladium vinyl complex that could undergo subsequent Sonogashira reaction with a second alkyne molecule. This alkylation-alkynylation sequence allowed the one-step synthesis of 1,3-enynes including heteroarenes and biologically active compounds with high efficiency without exogenous photosensitizers or oxidants and now opens up pathways towards cascade reactions via photochemical palladium catalysis.

Automated summary

A conceptually distinct approach was developed for the dicarbofunctionalization of alkynes at room temperature using simple alkyl iodides and a second molecule of alkyne as coupling partner. This method enables the one-step synthesis of 1,3-enynes with high efficiency without the need for exogenous photosensitizers or oxidants, paving the way for cascade reactions via photochemical palladium catalysis.