Synthesis of polyesters from terephthalaldehyde and isophthalaldehyde through Tishchenko reaction catalyzed by the ethylmagnesium bromide-(-)-sparteine complex and aluminum alkoxides

Terephthalaldehyde (TPA) and isophthalaldehyde (IPA) were polymerized with the ethylmagnesium bromide-(-)-sparteine (EtMgBr-Sp) complex and aluminum alkoxides as catalysts to obtain polyesters through the Tishchenko reaction. The polyester prepared from TPA with the EtMgBr-Sp complex was characterized by IR, FD mass, H-1 and C-13 NMR spectroscopies, and was found to be a random copolymer composed of oxycarbunyl-1,4-phenylenemethylene and terephthaloyloxymethylene-1,4-phenylenemethyleneoxy units. The polyesters possessed terminal formyl groups and were further polymerized with the EtMgBr-Sp complex. On the basis of the results, a possible mechanism for the polymerization is discussed.