Recent Advances in the Green Synthesis of Heterocycles: From Building Blocks to Biologically Active Compounds

Abstract

: Recent advances in the environmentally benign synthesis of common heterocycles are described. This account features three main parts; the preparation of non-aromatic heterocycles, one-ring aromatic heterocycles and their condensed analogs. Due to the great variety of and high interest in these compounds, this work focuses on providing representative examples of the preparation of the target compounds.

High pressure initiated solvent and catalyst-free instant Paal–Knorr reactions

“…The synthesis of the pyrroles attracted extensive attention due to their biological importance. 17 Our earlier investigations on the synthesis of pyrroles based on the Paal–Knorr reaction 18 resulted in efficient procedures. 19,20…”

Preparation of Deuterium Labeled Compounds by Pd/C-Al-D2O Facilitated Selective H-D Exchange Reactions

“…The deuteration of other compounds such as anilines, esters or alcohols is of great interests as well. Notably, they can serve as building blocks for the synthesis of compounds with medicinal relevance [ 36 , 37 , 38 ]. A few aniline derivatives were tested, and the conditions were optimized for each one of those substrates as well.…”

Recent Advances in the Synthesis of Isoquinoline-Fused Benzimidazoles

“…Recently, significant emphasis was placed on the environmental compatibility of the synthesis of heterocycles [ 43 , 44 ], including benzimidazo[2,1- a ]isoquinolines. Generally, phenyl-substituted benzimidazoles produce benzimidazo[2,1- a ]isoquinolines in reactions using either ketone or alkyne reagents.…”