A complex of formula (1), wherein, M is palladium or nickel, R1 and R2 are independently organic groups having 1-20 carbon atoms, or R1 and R2 are linked to form a ring structure with the phosphorus atom, R3 is selected from the group consisting of substituted and unsubstituted aryl, substituted and unsubstituted heteroaryl, and substituted and unsubstituted metallocenyl, R4 is an organic group having 1-20 carbon atoms, n is 0, 1, 2, 3, 4 or 5, X is an anionic ligand. A process for the preparation of the complex, and its use in carbon-carbon or carbon-nitrogen coupling reactions is also provided.