Derivatization of an especially electron-rich diborane.

Starting with electron-rich ditriflato-diborane B 2 (hpp) 2 (OTf) 2 (hpp = 1,3,4,6,7,8-hexahydro-2 H -pyrimido[1,2- α ]pyrimidinate), novel symmetric and unsymmetric diboranes B 2 (hpp) 2 X 2 and B 2 (hpp) 2 XY with X,Y = Br, NCS, N 3 or OTf are synthesized by substitution reactions with S N 1 mechanisms. The stability of the unsymmetric diboranes with respect to dismutation equilibria is evaluated.