Allenyl isothiocyanates, which can be easily generated by flash vacuum pyrolysis, are known to readily form 1,3-thiazoles with various nucleophiles. This is also true for heterocyclic aromatic amines and sterically hindered amines that are in other aspects used as non-nucleophilic bases. The chemistry of these synthetically useful cumulenes is now expanded to the field of multicomponent reactions with the mentioned amines and selected electrophiles. In an efficient, catalyst-free three-component reaction (3-CR) sequence, highly substituted heterocyclic compounds are formed containing the 2-amino-1,3-thiazole skeleton. The reaction conditions and mechanisms leading to these potentially bioactive molecules were investigated and optimized for the synthesis of a small compound library.