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