Recent Advances in Calix[4]arene-Catalyzed Synthesis of Five- and Six-Membered Oxa- and Azacycles

Heterocyclic compounds are not only ubiquitous in natural products, pharmaceuticals, and organic materials, but also function as essential ligands in both organic and medical chemistry. Among the current synthetic strategies, organocatalysis has garnered considerable attention in recent years owing to its cost-effectiveness, high catalytic efficiency, and environmental sustainability. In the realm of heterocycle synthesis via organocatalysis, calix[4]arenes have emerged as prominent catalysts. This review aims to highlight significant advancements in the calix[4]arene-catalyzed synthesis of five- and six-membered heterocyclic compounds using organic small molecules as starting materials over the past decade.