A facile synthesis of Robinson’s NHC-stabilised diborane(4)

Reactions of bis(pinacolato)diboron (B2pin2) with [(IDip)AlH3] (IDip = (HCNDip)2C:, Dip = 2,6-iPr2C6H3) afforded both the new diborane [(IDip)BH2B(pin)] and the known compound [(IDip)BH2BH2(IDip)] in a facile one-pot procedure; the latter reaction is improved by the addition of free IDip. [(IDip)AlH3] transfers both IDip and hydride ligands to the diborane moiety in a halide-free approach. [(IDip)BH2B(pin)] was structurally and spectroscopically characterised and additional spectroscopic data for [(IDip)BH2BH2(IDip)] is reported