gem-Difluoroolefination of Diazo Compounds with TMSCF3 or TMSCF2Br: Transition-Metal-Free Cross-Coupling of Two Carbene Precursors

• DOI: 10.1021/jacs.5b09888
• Publication Date: 2015-10-26T21:52:42Z
• Authors: Mingyou Hu; Chuanfa Ni; Lingchun Li; Yongxin Han; Jinbo Hu
• Keywords: Difluorocarbene

A new olefination protocol for transition-metal-free cross-coupling of two carbene fragments arising from different sources, namely, a nonfluorinated fragment resulting diazo compound and difluorocarbene derived Ruppert–Prakash reagent (TMSCF3) or TMSCF2Br, has been developed. This gem-difluoroolefination proceeds through the direct nucleophilic addition compounds to followed by elimination N2. Compared previously reported Cu-catalyzed with TMSCF3, which possesses narrow substrate scope due demanding requirement on reactivity in-situ-generated CuCF3, this affords general efficient approach various disubstituted 1,1-difluoroalkenes, including difluoroacrylates, diaryldifluoroolefins, as well arylalkyldifluoroolefins. In view ready availability reagents versatile transformations method is expected find wide applications in organic synthesis.