Palladium supported on N-Heterocyclic carbene functionalized hydroxyethyl cellulose as a novel and efficient catalyst for the Suzuki reaction in aqueous media

摘要

Bearing an intrinsic green nature, biopolymers are expected to serve as ideal alternatives in the sustainable conversion process. In this paper, a N-Heterocyclic carbene functionalized hydroxyethyl cellulose supported palladium catalyst (HEC-NHC-Pd) has been successfully prepared through a surface functionalization approach. The as-prepared catalyst was characterized through TEM, CP/MAS C-13 NMR, and XPS analyses, etc. The new and eco-friendly catalyst was effectively employed in Suzuki reactions in ethanol aqueous solution. Dependent on dual coordination sites (eOH and N-Methylimidazole) binding to the active component (Pd), the palladium complex exhibited high stability and low metal leaching ( 1%). Additionally, the environmental friendliness catalyst could be retrieved through simple centrifugation within a few cycles. This study also offers a new pathway for the application of such biopolymer surface functionalization in organic transformations.