Carbonylative Synthesis of 3-Substituted Thiochromenones via Rhodium-Catalyzed [3 + 2 + 1] Cyclization of Different Aromatic Sulfides, Alkynes, and Carbon Monoxide.

We have developed a rhodium-catalyzed carbonylative annulation methodology for the direct preparation of thiochromenones. With nonactivated aromatic sulfides and terminal alkynes as the substrates, the desired sulfur-containing six-membered heterocycles were prepared effectively via [3 + 2+1]-type annulation.