Sustainable Knoevenagel condensation catalyzed by recyclable biopolymer under concentrated solar radiation

Abstract

A sustainable Knoevenagel condensation protocol using recyclable chitosan as a biopolymer-based catalyst under concentrated solar radiation (CSR) has been developed. This green method eliminates conventional heating and harsh reagents by utilizing CSR as a renewable energy source. The catalyst is easily recoverable and reusable across multiple cycles with minimal activity loss, ensuring both environmental and economic advantages. The approach offers high yields (up to 98%) within short reaction times (8–28 min), demonstrating excellent atom economy and energy efficiency (89–99%) in alignment with green chemistry principles.

Graphical abstract