Enantiomerically Pure Bis(phosphanyl)carbaborane(12) Compounds

Enantiomerically pure (R-P,R-P)- and (R-P,S-P)-1,2-bis[1-adamantyloxy-(-)-menthyloxyphosphanyl]-closo-dicarbaborane(12), 1,2-bis[bis(-)-menthyloxyphosphanyl]-closo-dicarbaborane(12) and 1,2-bis[bis(4-tert-butylphenyloxy)phosphanyl]-closo-dicarbaborane(12) were synthesised by the reaction of dilithiated 1,2-dicarba-closo-dodecaborane(12) with two equivalents of the corresponding chlorophosphite. The phosphonites are stable towards epimerisation, oxygen and water. P center dot center dot center dot P through-space coupling was observed, and the (3)J(PP) coupling constants were determined by spectral simulation and DFT calculations. Late transition-metal complexes with molybdenum and rhodium were prepared to study the coordination proper-ties of the bis(phosphanyl)carbaborane(12) compounds. Catalytic properties of various rhodium complexes were investigated in homogeneous catalytic hydroformylation reactions with various olefins. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)