Silver compounds in synthetic chemistry : Part 5: Selective syntheses of trifluoromethylketones, RCOCF3, from trifluoromethylsilver, AgCF3, and corresponding acyl chlorides, RCOCl

Trifluoromethylketones of aromatics, heteroaromatics and olefins are formed selectively from reactions of trifluoromethylsilver and the corresponding carboxylic acid chlorides in moderate to excellent yields. The conditions chosen are dependent on the nature of the acyl chloride. Attempts to prepare alkyl(trifluoromethyl)ketones yielded product mixtures of the corresponding acyl fluorides, trifluoromethyl-, pentafluoroethyl- and n-heptafluoropropyl ketones.     

Halofluorination of 1,2-difluoro-1,2-di(p-tolyl)ethene, 1,2,3,4-tetrafluoro-1,4-di(p-tolyl) butadiene and its nonfluorinated parent compounds

The reactions of (E)-1,2-difluoro-1,2-di (p-tolyl) ethene (1) with N-bromo- or N-chlorosuccinimide gave mainly the expected halofluorination products 1-bromo-1,2-di(p-tolyl)-1,2,2-trifluoroethane (2) or 1-chloro-1,2-di(p-tolyl)-1,2,2-trifluoroethane (4), respectively. As a side reaction halogenation of the double bond has been obtained. With (E,E)-1,4-di(p-tolyl)-1,2,3,4-tetrafluorobuta-1,3-diene (6) under the same conditions the products of 1,2- and 1,4-addition or its consecutive hydrolysis products were isolated. (E)-Stilbene (19) on bromofluorination gave solely erythro-1-bromo-2-fluoro-1,2-diphenylethane (20), while with 1,4-diphenylbuta-1,3-diene (17) mainly higher molecular weight products were formed.