One-Pot Syntheses of Substituted Oxazoles and Imidazoles from the Isocyanide Asmic.

Substituted oxazoles and imidazoles are synthesized in one pot from the isocyanide building block Asmic (anisylsulfanylmethyl isocyanide), an alkyl halide, and an acid chloride or nitrile, respectively. The modular assembly employs sequential deprotonation-alkylation and deprotonation-acylation or imination of Asmic, followed by an unusual carbon-sulfur bond cleavage to construct the azole. The strategy is robust, highly efficient, and affords C4-C5 disubstituted oxazoles or imidazoles in a single operation.