(Sila)Difluoromethylation of Fluorenyllithium with CF3H and CF3TMS

• Main Authors: Kenichi Maruyama, Daichi Saito, Koichi Mikami
• Format: Article
• Language: English
• Published: Georg Thieme Verlag KG 2018-07-01
• Series: SynOpen
• Subjects: fluoroform; ruppert–prakash reagent; bioisostere; fluorene; difluoromethylation; difluoromethyl; difluoromethylene; difluorocarbene
• Online Access: http://www.thieme-connect.de/DOI/DOI?10.1055/s-0037-1610361

Abstract Difluoromethylation of the C9-H site of the fluorene ring using lithium base and fluoroform (CF3H), which is one of the most cost-effective difluoromethylating reagents, is attained to give difluoromethylated fluorenes with an all-carbon quaternary center. The Ruppert–Prakash reagent (CF3TMS) can also be applied to the present reaction system, providing siladifluoromethylated fluorenes that can be utilized for sequential carbon–carbon bond-forming reactions through activation of the silyl group.