Silver-Catalyzed Double Hydrocarbonation of 2-Trifluoromethyl-1,3-Conjugated Enynes with 1,3-Dicarbonyl Compounds: Synthesis of Ring-Trifluoromethylated Cyclopentene

An unexpected atom-economic tandem intermolecular hydrocarbonation and intramolecular hydrocarbonation (double hydrocarbonation sequence) of 2-trifluoromethyl-1,3-conjugated enynes with 1,3-dicarbonyl compounds leading to ring-trifluoromethylated cyclo-pentene frameworks by combination use of AgNO₃ as a catalyst and Et₃N as a base was developed. Enynes possessing electron-withdrawing aryl groups on the alkyne moiety are general good candidates for present transformation. (Figure presented.).