Divergent copper-catalyzed syntheses of 3-carboxylpyrroles and 3-cyanofurans from O-acetyl oximes and β-ketoesters/nitriles

Copper-mediated [3 + 2] oxidative cyclization of oxime acetate and its utility in the formal synthesis of fentiazac

A new protocol for the direct synthesis of 2-aminothiazole has been developed from oxime acetate and readily available sodium thiocyanate using a copper catalyst. The present transformation has good functional group tolerance. Various thiazoles were smoothly synthesized in good to excellent yields. The applicability of the present method has been extended to the formal synthesis of the non-steroidal and anti-inflammatory drug, fentiazac via the Sandmeyer reaction and Suzuki coupling.