The application of disubstituted vinylogous iminium salts and related synthons to the regiocontrolled preparation of unsymmetrical 2,3,4-trisubstituted pyrroles

Reactions of 2,3-disubstituted chloropropeniminium salts and related synthons with ethyl glycinate, ethyl N-methylglycinate, and ethyl N-benzylglycinate have been studied under acidic, basic and neutral conditions. Such reactions have resulted in efficient and selective methodology for the synthesis of unsymmetrical 2,3,4-trisubstituted pyrrole systems.