Abstract
Catalytic C-H activation-initiated annulation reactions have emerged as a versatile strategy for the effi-cient construction of diverse ring structural units and complex cyclic molecules in synthetic chemistry.Herein,we describe a new Rh(Ⅲ)-catalyzed C-H activation-initiated transdiannulation reaction of N,N-dimethyl enaminones with gem-difluorocyclopropenes in the presence of H2O,enabling a facile and oxy-gen transfer access to ring-fluorinated tricyclic γ-lactones with a 6-5 ring-junction tetrasubstituted stere-ocenter.This approach features bond-forming/annulation efficiency,good functional group tolerance and complete regioselectivity,which may include a complex process consisting of Rh(Ⅲ)-catalyzed C(sp2)-H activation,cyclic alkene insertion,defluorinated ring-opening of gem-difluorocyclopropane,intramolecular oxygen transfer,intramolecular cyclization and oxidative hydration.
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