Highly Efficient Heterogeneous Copper-Catalysed Coupling of Oxime Acetates with Isothiocyanates Leading to 2-Aminothiazoles

Abstract

The heterogeneous coupling reaction of oxime acetates with isothiocyanates was achieved at 110 °C in toluene in air in the presence of a bidentate nitrogen-functionalised MCM-41-immobilised copper(I) complex (MCM-41-2N-CuI) with Cs2CO3 as base to afford a variety of 2-aminothiazoles in good yields. The MCM-41-2N-CuI catalyst can be easily recovered by a simple filtration and reused at least eight times without significant loss of activity.

An overview on the copper‐promoted synthesis of five‐membered heterocyclic systems

“…The substituted acetophenone oxime acetates (124) containing both electron-donating and electronwithdrawing substitutions were coupled with substituted phenyl isothiocyanates (125) containing both electrondonating and electron-withdrawing substitutions to give 2-aminothiazole products (126) in 69-88% yields under standard reaction conditions (Scheme 31). [87] Yan et al described a domino synthesis of substituted imidazoindoles (128, 130, 132, 135 and 137) via a domino C-N, C-N cyclization process.…”