and have been shown to be capable of heterolysis of molecular hydrogen, a property that has led to their use in hydrogenation reactions of polarized multiple bonds. Here, we describe a general approach to the hydrogenation of alkynes to cis-alkenes under mild conditions using the unique ansa-aminohydroborane as a catalyst. Our approach combines several reactions as the elementary steps of the catalytic
In hexane, i.e. under heterogeneous conditions, 1,(omega-1)-dienes readily undergo double deprotonation to give bis(allylmetal) intermediates. In tetrahydrofuran at - 75 or - 50-degrees-C, however, only monometalation occurs with dienes having chains of up to 12 carbon atoms. The practical potential of such selective monosubstitution reactions is demonstrated by two novel pheromone syntheses.
MORET, ETIENNE;DESPONDS, OLIVIER;SCHLOSSER, MANFRED, J. ORGANOMET. CHEM., 409,(1991) N-2, C. 83-91