Transfer of hydrogen, oxygen, or both hydrogen and oxygen to unsaturated substrates from [ReH2(O)(Cyttp)]+ (Cyttp=PhP(CH2CH2CH2PCy2)2)

Synthesis and protonation of RuH(NBD)(2,6-(Ph2PCH2)(2)C6H3)

Protonation reactions of MH(Cl)(PPh3)(2)(norbornadiene) (M = Ru, Os)

Formation of New σ-Norbornenylrhodium(III) Complexes Promoted by Quinoline-8-carbaldehyde and Their Rearrangement into Nortricyclylrhodium(III) Derivatives. Formation of Norbornene and Nortricyclene

Publisher Summary This chapter focuses on the transition-metal complexes containing an “intact” dihydrogen ligand that constitutes a ubiquitous class of transition-metal compounds. It describes that homogeneous hydrogenation reactions of alkenes and alkynes involving η2-H2 metal complexes as either catalyst precursors or intermediates are relatively numerous. In most instances, the dihydrogen ligand is easily displaced by the incoming unsaturated substrate, which then inserts into a pre-existing M–H bond to give either M-alkyl or M-alkenyl. By doing so, a new free coordination site is generated for the activation of further H2 that ultimately brings about the hydrogenolysis of the M–C bond yielding either alkane or alkene and M–H. The chapter also highlights the range of ongoing applications and challenges of η2-H2 metal complexes in homogeneous and heterogeneous catalysis.

Chak Po Lau, ,‡ and

Papers

Reactions of MH(OTf)(NBD)(PPh3)2 (M ) Ru, Os) with H2