Dehydrocoupling Reactions of Secondary and Primary Amine-Borane Adducts Catalyzed by Half-sandwich Carbonyl Complexes, [CpMn(CO)3], [(η6-C6H6)Cr(CO)3], and [CpV(CO)4]

Dehydrocoupling reactions of amine-borane adducts catalyzed by half-sandwich carbonyl complexes are described. Secondary amine-borane adducts released H-2 with catalytic action of [CpMn(CO)(3)] (Cp: eta(5)-C5H5), [(eta(6)-C6H6)Cr(CO)(3)], and [CpV(CO)(4)] under photoirradiation to produce dimeric or monomeric aminoboranes. These results were parallel to the [M(CO)(6)]-catalyzed system (M = Cr, Mo, and W); however, the reactions were considerably slower. Dehydrocoupling of BH3 center dot NH2Me afforded an aminoborane polymer, [BH2NHMe](n).