Catalysts
The present invention relates to the field of polymerisation catalysts, and systems comprising said catalysts for polymerising carbon dioxide and an epoxide, a lactide and/or lactone, and/or an epoxide and an anhydride. The catalyst is of formula (I): Wherein M 1 and M 2 are independently selected from Zn(II), Cr(II), Co(II), Cu(II), Mn(II), Ni(II), Mg(II), Fe(II), Ti(II), V(II), Cr(III)-X, Co(III)-X, Ni(III)-X, Mn(III)-X, Fe(III)-X, Ca(II), Ge(II), Al(III)-X, Ti(III)-X, V(III)-X, Ge(IV)-(X) 2 or Ti(IV)-(X) 2 . R 3A is different from R 3B ; and/or at least one occurrence of E 3 , E 4 , E 5 and E 6 is different to a remaining occurrence of E 3 , E 4 , E 5 and E 6 . A ligand, a process of asymmetric N-substitution of a symmetrical ligand and a process for the reaction of: (i) carbon dioxide with an epoxide; (ii) an epoxide and an anhydride; and/or (iii) a lactide and/or a lactone, in the presence of a catalyst is also described.
1. A catalyst comprising one of the following:
2. The catalyst of claim 1 of the formula:
3. A process for the reaction of
(i) carbon dioxide with an epoxide;
(ii) an epoxide and an anhydride; and/or
(iii) a lactide and/or a lactone,
in the presence of the catalyst of claim 1 , optionally wherein the process is carried out in the presence of a chain transfer agent.
4. The process of claim 3 , wherein the process is carried out in a continuous flow reactor, or a batch reactor.
5. The process of claim 4 , wherein the reaction is carried out in a continuous flow reactor.