Recent progress on the synthesis of henna-based dibenzoxanthenes

Abstract

Xanthenes are a class of natural and synthetic heterocyclic compounds that exhibit a broad spectrum of biological properties and synthetic applications. The purpose of this current review is to demonstrate different synthetic methodologies for the construction of various dibenzo[a,i]xanthene, spiro-dibenzo[a,i]xanthene, dibenzo[b,i]xanthene, spiro dibenzo[b,i]xanthene, and dibenzo[b,h]xanthene derivatives by one-pot three-component reactions of lawsone, naphthols, and aldehydes or isatins or ninhydrin in the presence of homogeneous and heterogeneous catalysts under different conditions.