Cationic and homoleptic copper(i)–thiazol-2-ylidenes: highly reactive thiazole N-heterocyclic carbenes as σ-Lewis acid catalysts

Abstract

Air- and moisture-stable cationic homoleptic Cu(I)–thiazol-2-ylidene complexes are developed as highly efficient σ-Lewis acid catalysts, outperforming imidazol-2-ylidenes in the alkynylation of ketones without requiring stoichiometric Cu-acetylides. These complexes exhibit exceptional operational simplicity and robustness, enabling key C–C bond formation. Structural insights and DFT studies highlight their enhanced reactivity and stability. With their superior performance and practicality, thiazol-2-ylidenes represent a promising class of catalysts for sustainable organic synthesis.