Preparation, characterization and selective reactions of novel [1,3]diazetidine-2,4-diones (uretdiones) - A new route to generate asymmetric substituted toluylenediisocyanate-derivatives

The selective cyclodimerization of monomeric diisocyanates like IPDI 4 and TDI 5 yields [1,3]diazetidine-2,4-diones (uretdiones). On this basis, a new method for the selective transformation of the NCO-groups of asymmetric su bstituted diisocyanates is described. The reaction with different nucleophi les yields carbamates and ureas such as 9-11.