Copper-Catalyzed Trifluoromethylation and Bicyclizations of 1,7-Enynes Leading to Fused Polycycles

A series of trifluoromethyl-containing heterocycles, like indene and dihydroquinolinone or dihydrocoumarin-fused tetracyclic compounds have been prepared using copper-catalyzed cascade reaction of benzene-tethered 1,7-enynes. A study of the mechanism indicated that radical trifluoromethylation and sequential 6-exo-dig/5-endo-trig bicyclization processes were involved in this protocol. More-over, some selected products showed certain fungicidal activities against 14 kinds of plant fungi which means that these functionalized tetracyclic compounds might be used in the agrochemical field.