Synthesis of Cyclopropenols Enabled by Visible‐Light‐Induced Organocatalyzed [2+1] Cyclization

Abstract Although the synthesis of common cyclopropenes has been well studied, the access to cyclopropenols is rather limited. Herein, we report the first synthesis of α ‐ trifluoromethylated cyclopropenols via 2+1 cycloaddition reactions between alkynes and trifluoroacylsilanes, enabled by visible‐light‐induced organocatalysis. The novel ambiphilic donor–acceptor carbenes derived from trifluoroacetylsilanes reacted efficiently with both activated and non‐activated alkynes. The reaction features simple operation, mild conditions, broad substrate scope and good functional group tolerance. The synthetic potential of the reaction is highlighted by the gram‐scale reactions and first synthesis of α‐trifluoromethylated cyclopropanols through the combination of the 2+1 cyclization and high diastereoselective hydrogenation reaction in one pot.