Tuning the [L_2Rh••• H_3BNR_3]~+ interaction using phosphine bite angle.Demonstration by the catalytic formation of polyaminoboranes

摘要

Efficient catalysts for the dehydrocoupling or dehydropoly-merisation of H_3B-NMe_xH(3-x) (x = 1, 2) have been developed by variation of the P-Rh-P angle in {Rh(Ph_2P(CH_2)_nPPh_2)} ~+ fragments (n = 2-5). The dehydrocoupling of amine-boranes, H_3BNR_2H (R = alkyl, H), continues to attract considerable interest.1 Although much of this has been driven by their potential for use as chemical hydrogen storage materials,2 the recent report by one of our groups of the synthesis of high molecular weight polyaminoborane, [H2BNMeH]_n, from the dehydrocoupling of H3BNMeH2 using Ir(POCOP)H_2, (POCOP = [k~3-1,3-(~tBu_2PO)_2C_6H_3]) is an exciting recent development.