Triazaboles and Related Triazole Derivatives of Boron

摘要

The reaction of trimethylamine-borane, Me3NBH3, with 1,2,4-triazole (=Hst) results in the formation of an oligomer mixture of the composition H2B (st)n; species with n up to six could be identified by mass spectrometry. Dimeric species = sym-triazoboles, R2B(mu-st)2BR2(2,R = hydrocarbon group), can be obtained in low yield from the condensation of R3B with Hst, the interaction of (halo) diorganylboranes, R2BX (X = CI, Br) with N-trimethylsilyl-1,2,4-triazole (=Hat) with excess of R3B ultimately gives a resonable yield of mixture of two isomeric. Triazaboles of type 2 with the amino groups in either the 1,5 or 1,7 positions, whereas transamination of Me2NBR2 with Hat preferentially gives the 1,5-diamino isomer but in low yield. Several Boron Derivatives of 1,2,3-triazoles have been isolated and characterized; these include tetrameric species (derived from 1,2,3-triazole = Hut, or benzotriazole = Hbt) with a cyclic structure (6) resembling that of porphin, but also oligomeric materials R2B(ut)n and R2B(bt)n Keywords: N-triazolylboranes, Tetramers, N-triazolylboranes, Oligomers. (aw)