Silica grafted DBU Supported NiCl2 : A Sustainable heterogeneous catalyst for A3 coupling

Abstract

Silica grafted DBU supported NiCl2 complex, SiO2@DBU-NiCl2 has been designed and synthesized by multistep approach and characterized by FT-IR, XRD, EDS, FE-SEM and TGA. Catalytic activity of SiO2@DBU-NiCl2 has been explored for A3 coupling of terminal alkynes, aldehydes and secondary amines. Special features of present protocol are high TONs and TOFs, low catalyst loading (0.08 mol %), solvent-free conditions and reusability of the catalyst.