Borylimide catalysts

A compound of Formula (I):

• wherein:
• M is selected from titanium, zirconium and hafnium;
• X1 and X2 are independently selected from halo, hydrogen, a phosphonate, sulfonate or boronate group, amino, (1-6C)alkyl, (1-6C)alkoxy, aryl, aryloxy and heterocycloalkyl (such as THF), wherein said (1-6C)alkyl, (1-6C)alkoxy, aryl and aryloxy groups may be optionally substituted with one of more groups selected from halo, oxo, hydroxy, amino, nitro, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, (1-6C)haloalkyl, (1-6C)alkoxy, aryl and Si[(1-4C)alkyl]3;
• Y is BR1R2;
• Z is a polydentate ligand coordinated to M by at least 2 donor atoms Q, wherein each Q is independently selected from N, O, S and P;
• R1 and R2 are independently selected from NR3R4, OR5, SR6 and CR7R8R9;
• R3, R4, R5, R6, R7, R8 and R9 are independently selected from hydrogen, (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, aryl and heteroaryl, wherein said (1-6C)alkyl, (2-6C)alkenyl, (2-6C)alkynyl, aryl and heteroaryl groups are optionally substituted with one or more substituents selected independently from halo, hydroxy, amino, nitro, (1-6C)alkyl and (1-6C)haloalkyl;
• or R1 and R2 are linked, such that when taken in combination with the boron atom to which they are attached, they form a group:
• wherein ring A is a carbocyclic or heterocyclic ring, optionally substituted with one or more substituents selected independently from halo, hydroxy, amino, (1-6C)alkyl, (1-6C)alkoxy, (1-6C)haloalkyl, aryl and heteroaryl, wherein said aryl and heteroaryl groups are optionally substituted with one or more substituents selected independently from halo, hydroxy, amino, nitro, (1-6C)alkyl and (1-6C)haloalkyl.