5-di(tert-butyl)pyrazole (3d), 3,5-bis(trifluoromethyl)pyrazole (3e)). The synthesis approach thus provides access to uncharged B–N triptycenes bearing (i) functionalisable groups, (ii) electron-donating or -withdrawing substituents and (iii) pyrazole rings of varying steric demand. Treatment of p-R*C6H4BBr2 with the potassium tris(pyrazol-1-yl)borates K[HBpz3] or K[p-R*C6H4Bpz3] yields cationic pyrazolyl-bridged
在Me 3 SiCl存在下,双
硼酸酯Li 2 [ o -C 6 H 4(BH 3)2 ]与2当量适当的
吡唑衍
生物(Hpz R)之间的反应产生邻苯撑桥连的
吡唑HB(μ- pz R)2(μ- o -C 6 H 4)BH(3a-3e ; Hpz R =
4-碘吡唑(3a),4-(三甲基甲
硅烷基)
吡唑(3b),
3,5-二甲基吡唑(3c),3 ,5-二(叔)-丁基)
吡唑(3d),3,5-双(三
氟甲基)
吡唑(3e))。因此,该合成方法可提供带有(i)可官能化基团,(ii)给电子或吸电子取代基和(iii)空间需求变化的
吡唑环的不带电荷的B-N三联烯。用三(
吡唑-1-基)
硼酸钾K [HBpz 3 ]或K [ p- R * C 6 H 4 Bpz 3 ]处理对-R * C 6 H 4 BBr 2产生阳离子
吡唑基桥连的
吡唑并[ p -BrC 6 H 4 B(μ-pz)3 BH] Br([4a ] Br)和[ p