Stereoselective Fluoroalkylacylation of Alkynes via Cooperative N-Heterocyclic Carbene/Palladium Catalysis

Herein, a cooperative N-heterocyclic carbene- and palladium-catalyzed three-component reaction of alkynes with aldehydes and fluoroalkyl iodides is developed. A series of biologically valuable CF2 R-incorporated alpha-substituted enones was obtained in moderate to good yields. This mild catalytic method exhibits exclusive regio- and stereoselectivity, excellent functional group tolerance, and a broad substrate scope including terminal and internal alkynes. Mechanistic investigations disclose that this alkyne fluoroalkylacylation proceeds via a radical relay process in which vinyl iodides serve as putative reaction intermediates.