Friedel−Crafts-Type Cyclization of 2,2-Difluorovinyl Ketones via α-Fluorocarbocations and Its Application in Domino Cyclizations
摘要:
2,2-Difluorovinyl ketones bearing an aryl group undergo Friedel-Crafts-type cyclization via carbocations stabilized by alpha-fluorines on treatment with a trimethylsilylating agent [Me3SiOTf or Me3SiB(OTf)(4)]. The reaction affords 4-fluorinated 3-acyl-1,2-dihydronaphthalenes, which are successfully subjected to a substitution-cyclodehydration process or a Nazarov-type cyclization to construct fused polycyclic systems.
2,2-Difluorovinyl ketones bearing an aryl group undergo Friedel-Crafts-type cyclization via carbocations stabilized by alpha-fluorines on treatment with a trimethylsilylating agent [Me3SiOTf or Me3SiB(OTf)(4)]. The reaction affords 4-fluorinated 3-acyl-1,2-dihydronaphthalenes, which are successfully subjected to a substitution-cyclodehydration process or a Nazarov-type cyclization to construct fused polycyclic systems.