Nucleophilic trifluoromethylation and difluorination of substituted aromatic aldehydes with Ruppert’s and Deoxofluor™ reagents

Efficient, high yield syntheses of 2,2,2-trifluoro-1-(N,N-dialkylaminophenyl)-ethanols (3a, b) and 2,2,2-trifluoro-1-(hydroxyaryl)ethanols (6c–g) by reacting Ruppert’s reagent, (trifluoromethyl)trimethylsilane (TMSCF3), with appropriate substrates in the presence of a catalytic amount of cesium fluoride are described. A versatile route to the synthesis of substituted aryl difluoromethane derivatives (8h–l, 10m, 12n, o, 14p) and the reactivity of substituted aromatic aldehydes towards bis(2-methoxyethyl)aminosulfur trifluoride (Deoxofluor™) were also investigated.