We herein describe the development of a dimerization procedure for amino acids to prepare 2,5-disubstituted thiazoles and oxazoles in the presence of Na2S⋅9H2O and H2O, respectively. These approaches enabled the direct formation of five-membered ring systems bearing two different heteroatoms from two amino acid units. Mechanically, decarboxylation, deamination, S/O insertion, cyclization and gradient oxidation processes were involved in the oligomer formation. (Figure pres...
