Terphenyl-derived covalent organic polymer for the cycloaddition reaction of carbon dioxide with spiro-epoxy oxindoles

Abstract

Covalent organic polymers are a class of fascinating material derived from pre-designed molecular scaffolds with tailorable structural features. The choice of designed functionalities and prospective strategy for its preparation enables them to address the application requirements. In this work, we report the synthesis of a spherical covalent organic polymer (COP) derived from terphenyl structural unit, achieved through a template-free condensation reaction. The prepared material demonstrated efficient organocatalytic activity toward the cycloaddition reaction of carbon dioxide with spiro-epoxy oxindoles to access spirocyclic carbonates (63%–99%) under ambient reaction conditions. Notably, the organic material outperformed its corresponding monomeric unit, which clearly reveals the requirement of a covalent organic polymer. The heterogeneous organic material is found to be recyclable for four times with retention of its catalytic activity. The calculated green metrics reveal that the developed catalytic protocol is efficient, creates minimal waste, and is environmentally friendly.