Selective hydrogenation

Selective hydrogenation using at least one catalyst of formula (I)

• wherein
• M is Rh or Ir, and
• L is a bidentate phosphine ligand of formula (II)
• wherein
• R is a substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl or isopropyl, and
• R1 is a substituted or unsubstituted cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, anisyl, tert-butyl or isopropyl, and
• A is a bridging moiety chosen from the group consisting of
• —(CH2)m—, wherein m is an integer of value 1-6;
• X− is a halide, −OAc, −OH or −OCH3
• and wherein any dotted line in formulae represents the bond by which the substituent is bound to the rest of the molecule.