Patent ID: 7250526

Claim:
A catalyst having the general formula: in which: R 18 represents an optionally substituted hydrocarbyl or perhalogenated hydrocarbyl ligand; A represents —NR 19 —, —NR 20 —, —NHR 19 , —NR 19 R 20 or —NR 20 R 21 where R 19 is H, C(O)R 21 , SO 2 R 21 , C(O)NR 21 R 25 , C(S)NR 21 R 25 , C(═NR 25 )SR 28 or C(═NR 25 )OR 26 , R 20 and R 21 each independently represents an optionally substituted hydrocarbyl, perhalogenated hydrocarbyl or an optionally substituted heterocyclyl group, and R 25 and R 26 are each independently hydrogen or a group as defined for R 21 ; B represents —O—, —OH, OR 22 , —S—, —SH, SR 22 , —NR 22 —, —NR 23 —, —NHR 23 , —NR 22 R 23 , —NR 22 R 24 , —PR 22 — or PR 22 R 24 where R 23 is H, C(O)R 24 , SO 2 R 24 , C(O)NR 24 R 27 , C(S)NR 24 R 27 , C(═NR 27 )SR 28 or C(═NR 27 )OR 28 , R 22 and R 24 each independently represents an optionally substituted hydrocarbyl, perhalogenated hydrocarbyl or an optionally substituted heterocyclyl group, and R 27 and R 28 are each independently hydrogen or a group as defined for R 24 ; E represents a linking group comprising 2–4 carbon atoms linking A and B, said carbon atoms optionally carrying one or more substituents; M represents a Group VIII transition metal capable of catalysing transfer hydrogenation; and Y represents an anionic group, a basic ligand or a vacant site; provided that when Y is not a vacant site that at least one of A or B carries a hydrogen atom, characterised in that at least one of said groups R 20 to R 22 or R 24 to R 28 is present in the form of an optionally substituted sulphonated hydrocarbyl group, a sulphonated perhalogenated hydrocarbyl group, or an optionally substituted sulphonated heterocyclyl group.