Hydrogenation and isomerization of oct-1-ene by (Ph3P)2MX2 and other complexes

Abstract

Complexes (Ph₃P)₂MX₂ with stannous chloride in benzene + methanol catalyze the hydrogenation of oct-1-ene (H₂, 1 atm, 20°) with a rate sequence: M = Pd > Pt > Ni; X = Cl > Br > I > CN. Under hydrogenation conditions, oct-1-ene is isomerized to oct-2-ene when M = Pd or Pt and X = Cl or Br, but not when X = I or CN or if M = Ni. Isomerization requires the presence of hydrogen. A second group of complexes, (Ph₃P)₃RhCl, (Ph₃P)₂RhCOCl, (Ph₃P)₂IrCOCl, and [(Ph₃P)₆Ru₂Cl₃]Cl isomerizes oct-1-ene in absence of hydrogen.