Syntheses and Structures of Epoxide Adducts of Soluble Cadmium(Ⅱ) Carboxylates. Models for the Initiation Process in Epoxide/CO_2 Coupling Reactions

摘要

Complexes 1 and 2 represent well-characterized metal—epoxide complexes. Our studies indicate that the epoxide ligand is relatively weakly binding toward Cd(Ⅱ), much more so than THF and thiirane ligands. Furthermore, we have observed coupling of the epoxide ligand with the carboxylate group in these metal complexes to subsequently provide oligomers of the epoxide with terminal ester groups. In analogous reactions carried out in the presence of carbon dioxide, cyclic carbonates are also formed. Hence, these cadmium complexes appear to be excellent models for mimicking the catalytic properties of the more reactive, poorly characterized catalysts derived from Zn(Ⅱ) dicarboxylates.