CHLOROFLUOROCARBENE FROM REACTION OF FLUOROTRICHLOROMETHANE WITH REDUCED TITANIUM - SYNTHESIS OF 1-CHLORO-1-FLUOROCYCLOPROPANES

Generation of chlorofluorocarbene by reaction of CFC13 with reduced titanium at 0 °C, in the presence of various alkenes, produces 1-chloro-l-fluorocyclopropanes in good yield. Evidence from the syn/anti product ratios, including generation of chlorofluorocarbene from CFBr2Cl, indicates that a free carbene and not a “carbenoid” species is involved. Solvent effects, effects of ratios of reagents, and the efficacy of other metals in this reaction were also examined. A cursory examination of PhCCl3, CH3CC13, and CF2Br2 in this reaction indicated that they are also useful carbene precursors, while CHC13, CHFBr2, and CHFI2 were all found to be ineffective. © 1990, American Chemical Society. All rights reserved.