The first N, N'-ditosyl-substituted cyclic boron cation, stabilized by neighboring-group participation by two sulfonyl groups, and the alternative, stabilized by polar solvents

Abstract When 2-bromo-1,3-ditosyl-1,3,2-diazaborolidine was treated with AgSbF 6 , a novel cyclic boron cation was formed in CD 2 Cl 2 , the 11 B NMR chemical shift of which appeared at 8.7 ppm. Ab initio calculations were consistent with the cationic boron center being stabilized by neighboring-group participation of the two sulfonyl functions. The reaction in CD 3 NO 2 resulted in an alternate formation of a cyclic boron cation species (16.2 ppm), stabilized by coordination to the basic solvents.