SYNTHESIS OF POLYIMIDES VIA THE PALLADIUM-CATALYZED CARBONYLATION OF BIS(O-IODO ESTERS) AND DIAMINES

A new method is described for the synthesis of polyimides utilizing bis(o-iodo esters) and primary diamines in the presence of carbon monoxide (GO) and a palladium catalyst. A goal of isolating the intermediate poly(amide esters) from these reactions was not realized. Under all conditions examined in the model systems, neutralizing bases suitable for promoting the carbonylation reaction also induced cyclization to the fully imidized product; intermediate amide esters were not observed. Hydrogen iodide traps such as olefins were also examined, but did not ave the desired amide esters. Polyimides formed by this method were fully imidized and had thermal stability commensurate with conventionally prepared polymers. However, the synthetic scope of this method was limited to fully imidized polymers that were soluble in dipolar aprotic solvents.