Synthesis and Structure of Stable α-Boranyldiazomethanes: 1,3-Di-<i>tert</i>-butyl-2,3-dihydro-1<i>H</i>-1,3,2-diazaborolyl- (trimethylsilyl)diazomethane and 1,3-diethyl-2,3-dihydro-1<i>H</i>-1,3,2-benzodiazaborolyl- (trimethylsilyl)diazomethane

Reaction of equimolar amounts of Me3SiC(N2)Li with the 2-bromo-2,3-dihydro-1H-1,3,2-diazaborolederivatives (1), (3), and (5) afforded the 1,3,2-diazaborolyldiazomethanes (2), (4), and (6). The X-ray structure analysis of 2 revealed a planar five-membered heterocycle which is linked to the carbon atom of the diazomethyl unit via a B−C single bond. π-Interactions between this carbon atom and the boron atom can thus be excluded.