CO2-facilitated radical sequential (3 + 2) annulation of 1,6-enynes via cooperation of sulfinate catalysis and photocatalysis

Reported here is the radical sequential (3 + 2) annulation of 1,6-enynes under the concerted catalysis of sulfinate and PC. Importantly, CO 2 as a green additive facilitates the unusual 1,4-elimination via proton transfer to provide desulfonylated products.