Copper-catalyzed cascade cyclization of 1,5-enynes via consecutive trifluoromethylazidation/diazidation and click reaction: self-assembly of triazole fused isoindolines†
Abstract
Copper-catalyzed cascade cyclization of 1,5-enynes with two types of hypervalent reagents was developed via consecutive trifluoromethylazidation/diazidation and intramolecular click reaction (CUAAC), providing one-pot self-assembly of triazole fused isoindolines bearing a trifluoromethyl or an azide moiety. Moreover, the construction of a trifluoromethylcyclopropyl unit, which has been considered as a metabolically stable replacement for a tert-butyl moiety and was difficult to access, was also achieved under trifluoromethylazidation conditions. All these reactions exhibited excellent chemoselectivity, good to excellent yields and broad functional group tolerance.