Synthesis and Reactions of Five-Membered Heterocycles Using Phase Transfer Catalyst (PTC) Techniques

Abstract

Phase transfer catalysts (PTCs) have been widely used for the synthesis of organic compounds particularly in both liquid-liquid and solid-liquid heterogeneous reaction mixtures. They are known to accelerate reaction rates by facilitating formation of interphase transfer of species and making reactions between reagents in two immiscible phases possible. Application of PTC instead of traditional technologies for industrial processes of organic synthesis provides substantial benefits for the environment. On the basis of numerous reports it is evident that phase-transfer catalysis is the most efficient way for generation and reactions of many active intermediates. In this review we report various uses of PTC in syntheses and reactions of five-membered heterocycles compounds and their multifused rings.

Development of Sustainable Chemistry in Madagascar: Example of the Valuation of CNSL and the Use of Chromones as an Attractant for Mosquitoes

“…In our study, the reaction was carried out with ethyl chloroacetate in the presence of potassium carbonate and a small amount of quaternary ammonium (tetrabutylammonium acid sulphate) as a phase transfer catalyst. Potassium carbonate is used to deprotonate the hydroxyl functions of the starting product [30] while quaternary ammonium is used to perform solid/liquid phase transfer [31]. Ethyl chloroacetate is used both as a reagent and as a solvent, so we put it in excess of 10 mol/mol.…”

Synthesis and Characterization of 1-(1-chlorocyclopropyl)-2-(1,2,4-triazol-1-yl)ethan-1-one

“…However, from a practical standpoint, their high cost and toxicity were limitations for their application to our purposes. Consequently, we evaluated several PEGs and quaternary ammonium salts as PTCs for the N-alkylation of 1,2,4-triazole 14- 15 . The relative catalytic effi ciency of each is displayed in Table 2, revealing the highest conversion rate for PEG-1000.…”

Synthesis and Toxicological Effect of Some New Pyrrole Derivatives as Prospective Insecticidal Agents against the Cotton Leafworm, Spodoptera littoralis (Boisduval)

“…As a consequence, reaction rates have been accelerated. 30,31 economic and environmental benefits for commercial organic synthesis operations. Many studies have shown that PTC is the most efficient approach to produce a large number of active intermediates.…”