Sandmeyer Difluoromethylation of (Hetero-)Arenediazonium Salts
作者:Christian Matheis、Kévin Jouvin、Lukas J. Goossen
DOI:10.1021/ol5030037
日期:2014.11.21
straightforward conversion of (hetero-)arenediazonium salts into the corresponding difluoromethyl (hetero-)arenes under mild conditions. The actual difluoromethylating reagent, a difluoromethyl–copper complex, is formed in situfrom copper thiocyanate and TMS–CF2H. The diazonium salts are either preformed or generated in situfrom broadly available aromatic amines.
[18F]arylCF3 and [18F]arylCHF2 derivatives from arylCF2Br and arylCHFCl precursors applying a silver-mediated halogenexchange with [18F]fluoride. In the absence of Ag(I)OTf, no reaction takes place at room temperature for both classes of substrates; this result demonstrates the beneficial role of silver(I) as a means to induce 18F-incorporation under very mild conditions.
Copper-Mediated Difluoromethylation of Aryl and Vinyl Iodides
作者:Patrick S. Fier、John F. Hartwig
DOI:10.1021/ja301013h
日期:2012.3.28
straightforward method for the cross-coupling of aryl and vinyliodides with a difluoromethyl group generated from readily available reagents to form difluoromethylarenes and difluoromethyl-substituted alkenes. The reaction of electron-neutral, electron-rich, and sterically hindered aryl and vinyliodides with the combination of CuI, CsF and TMSCF(2)H leads to the formation of difluoromethyl-substituted
The study of transition-metal difluorocarbene complex has long been a subject of active investigation, but the transition-metal-catalyzed transfer of difluorocarbene remains a significant challenge. The Pd-catalyzed transfer of difluorocarbene is described to realize the coupling reaction of boronic acids with difluorocarbene to give (difluoromethyl)arenes and -olefins. Mechanistic investigations reveal