New phosphonium bromobismuthate as selective catalytic reagent in the heterocyclization reactions

Abstract

A new hybrid phosphonium bromobismuthate compound was synthesized and characterized by 1H NMR, 13C NMR, 31P NMR, FT‐IR, differential scanning calorimetry (DSC) and single‐crystal X‐ray diffraction analysis. The crystal packing structures of title compound were stabilized by various intermolecular interactions especially of the type CH···Br hydrogen bonds between phosphonium cations and [Bi2Br9]3− anion. The relative contribution of various close contacts and 2D fingerprint plots of title compound and three analogous structures obtained from Cambridge Structural Database (CSD) were investigated by Hirshfeld surface analysis. Furthermore, the catalytic activity of title compound was investigated in heterocyclization reaction for the synthesis of significant and pharmacologically useful benzimidazole and benzoxazole derivatives. The results indicated that the yields of the product for aldehydes bearing p‐substituents and o‐substituents were higher than for m‐substituent ones. In addition to selectivity, simplicity of operation, waste minimization, ease of manipulation, short reaction time, excellent yield of product, and easy workup, this technique uses title compound as the catalyst, which is green, recyclable, soft, remarkably nontoxic, and easy to handle.