Generation of heteroarylium-N-difluoromethylides and heteroaryl-N-difluoromethyl anions and their reactions with electrophiles:: heteroaryl- and heteroarylium-N-difluoromethyl trimethylsilanes and a new heteroaryl-N-trifluoromethane

Reductive debromination of N-bromodifluoromethyl-4-dimethylaminopyridinium bromide. 1-bromodifluoromethyl-imidazole, 1-methyl-3-bromodifluoromethyl-imidazolium bromide and 1-bromodifluoromethyl-2-methyl-benzimidaz using tetrakis(dimelhylamino)ethylene (TDAE) or tris(diethylamido)phosphite leads to new fluorinated carbanionic species, namely heteroarylium-N-difluoromethylides and heteroaryl-N-difluoromethyl anions. In the presence of electrophiles such as benzaldehyde, chlorodiphenylphosphine and chlorotrimethylsilane, the corresponding heteroarylium- and heteroaryl-N-difluoromethylated derivatives, imidazole-N-difluoromethyl-phosphines and -silanes, 2-methyl-benzimidazole-N-difluoromethyltrimethyl-carbinols-phosphines and -silanes were obtained. Similar 4-dimethylaminopyridinium derivatives were synthesized, (C) 2001 Elsevier Science B.V. All rights reserved.