Copper‐Catalyzed Trifluoromethylation of N,N‐Dialkylhydrazones

Abstract

Von (hetero)aromatischen Aldehyden abgeleitete N,N‐Dialkylhydrazone können bei Raumtemperatur mit Tognis Reagens unter CuCl‐Katalyse trifluormethyliert werden (siehe Schema). Die einfache Reaktion liefert nützliche trifluormethylierte Synthesebausteine und verläuft vermutlich über eine radikalische CF3‐Übertragung.

6‐Trifluoromethyl‐Phenanthridines through Radical Trifluoromethylation of Isonitriles

“…As source of the CF 3 radical we used the Togni reagent 2 ,8, 9 and initial investigations were conducted on isonitrile 1 a . Because CF 3 radicals are generated in the reaction of Cu I salts with the Togni reagent,9a,b,j we first screened various Cu salts as initiators/catalysts (see mechanistic discussion below) in 1,4‐dioxane at 70 °C using a slight excess (1.2 equiv) of the trifluoromethylation reagent 2 .…”

Palladium‐Catalyzed C(sp2)−H Alkylation of Aldehyde‐Derived Hydrazones with Functionalized Difluoromethyl Bromides

“…[2] Given the unique properties that fluorine substitution can impart on molecules, [3] we recently became interested in the development of methods for C(sp 2 ) À He lectrophilic fluoroalkylation of aldehyde-derived hydrazones,thus anticipating that this would expand their application to potentially useful organofluorine molecules for biological investigations. [5] Our current efforts are now focusing on the discovery of efficient protocols for the direct introduction of functionalized difluoromethylene (CF 2 )g roups.T he CF 2 moiety has attracted significant attention in recent years with applications arising in various areas,including medicinal chemistry.For instance,the difluoromethylene moiety (CF 2 R, CF 2 H) has been recognized as ap otential bioisostere of hydroxy or thiol groups,a sw ell as ac arbonyl group.T he benefits include increased acidity of proximate functional groups and conformational changes. [5] Our current efforts are now focusing on the discovery of efficient protocols for the direct introduction of functionalized difluoromethylene (CF 2 )g roups.T he CF 2 moiety has attracted significant attention in recent years with applications arising in various areas,including medicinal chemistry.For instance,the difluoromethylene moiety (CF 2 R, CF 2 H) has been recognized as ap otential bioisostere of hydroxy or thiol groups,a sw ell as ac arbonyl group.T he benefits include increased acidity of proximate functional groups and conformational changes.…”

Difluoromethylation of heterocyclesviaa radical process

“…Cyano and ester-substituted substrates were also compatible, delivering the corresponding quinolines 133 and 124 in acceptable yields. Based on the controlled experiments and previous reports, 66–70 a plausible radical pathway was proposed. Initially, the difluoromethyl radical 15A could be smoothly generated through a SET process.…”