The present invention relates to a new chemical synthesis, intermediates and catalysts useful for the preparation of the neprilysin (NEP) inhibitor sacubitril. It further relates to new intermediate compounds and their use for said new chemical synthesis route.

The present invention provides unimolecular metal complexes having increased activity in the copolymerization of carbon dioxide and epoxides. Also provided are methods of using such metal complexes in the synthesis of polymers. According to one aspect, the present invention provides metal complexes comprising an activating species with co-catalytic activity tethered to a multidentate ligand that is coordinated to the active metal center of the complex.

A continuous preparation method for a low-odor phosphazene catalyst and use thereof are provided. The phosphazene catalyst includes a phosphazene cation and an alkali metal salt compound anion represented by General Formula (I); and the phosphazene catalyst is prepared by using phosphorus pentahalide and a guanidine compound as raw materials, dissolving the phosphorus pentahalide in an organic non-benzene solvent to react under heating conditions, then obtaining an organic phosphonium salt solution containing the organic non-benzene solvent and a halogenated phosphorus compound, adding the alkali metal salt compound to react under an inert atmosphere and heating conditions, and then filtering, distilling under a reduced pressured, purifying and vacuum drying. The phosphazene catalyst is used in the preparation of polyether polyols and polyurethane foam materials.