Rearrangement Reactions; 14: Synthesis of Functionalized Thiazoles via Attack of Heteroatom Nucleophiles on Allenyl Isothiocyanates

Treatment of allenyl isothiocyanates with sulfur-. oxygen-, nitrogen- or hydride-containing nucleophiles such as propane-2-thiol, thiophenol. hydrogen sulfide, alcohols, phenol or aqueous NaOH. NH 3 , primary or secondary aliphatic or aromatic amines, N,N,N',N'-tetramethylguanidine or sodium cyanoborohydride resulted in ring closure to generate thiazoles bearing a functionality at position C-2 in most cases. Moreover, we report the first examples of aromatic thiazole-2-phosphonates prepared by the same strategy using dialkyl or diphenyl phosphites as nucleophiles.