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
作者:German Bissky、Gerd-Volker Röschenthaler、Enno Lork、Jan Barten、Maurice Médebielle、Vasilij Staninets、Alexander A. Kolomeitsev
DOI:10.1016/s0022-1139(01)00390-6
日期:2001.7
1-bromodifluoromethyl-2-methyl-benzimidazole using tetrakis(dimethylamino)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
Heteroaryl-<i>N</i>-difluoromethyltrimethylsilanes - Versatile Sources of Heteroaryl-<i>N</i>-difluoromethyl Anions in Reactions with Carbonyl Compounds
作者:German Bissky、Vasilij I. Staninets、Alexander A. Kolomeitsev、Gerd-Volker Röschenthaler
DOI:10.1055/s-2001-11389
日期:——
An efficient procedure for synthesizing heteroaryl-N-difluoromethyltrimethylsilanes - new nucleophilic difluoromethylene synthons - from easily available N-bromodifluoromethylated heterocycles, chlorotrimethylsilane and aluminium powder in triglyme or N-methylpyrrolidinone on a preparative scale in 71-75% isolated yield is described. Heteroaryl-N-difluoromethyltrimethylsilanes and benzaldehyde react under fluoride ion catalysis to give 1-(1,1-difluor-2-hydroxy-2-phenyl-ethyl)heteroaryls, whereas for anionic heteroaryl-N-difluoromethylation of cyclohexanone a stoichiometrical mixture of heteroaryl-N-difluoromethyltrimethylsilanes and tetramethylammonium fluoride has to be used.