Green methodologies for the synthesis of 2-aminothiophene

Abstract

Pollution and the rising energy demand have prompted the design of new synthetic reactions that meet the principles of green chemistry. In particular, alternative synthesis of 2-aminothiophene have recently focused interest because 2-aminothiophene is a unique 5-membered S-heterocycle and a pharmacophore providing antiprotozoal, antiproliferative, antiviral, antibacterial or antifungal properties. Here, we review new synthetic routes to 2-aminothiophenes, including multicomponent reactions, homogeneously- or heterogeneously-catalyzed reactions, with focus on green pathways.

Green Synthesis of Pyrazoles: Recent Developments in Aqueous Methods

“…[1][2][3][4][5] The green approaches which are mainly considered for the organic synthetic reactions are (i) use of green solvents like nature's solvent, the water, as reaction medium instead of organic solvent (ii) reactions in solid state without using any solvent at all (iii) using catalytic amount of organometallic reagents instead of stoichiometric amounts (iv) preference for biosynthetic processes. For the synthesis of heterocyclic compounds, many green methods have been applied, [6][7][8][9] performing the reactions at ambient temperature and using alternative energy sources being the methods of choice.…”

Synthesis of Five-Membered Heterocycles Using Water as a Solvent

“…A simple and convenient synthesis of 2-aminothiophenes was investigated by the reaction of ketones with malononitrile using water as a solvent in a reaction ignited by sodium polysulfides in catalyst-free conditions under ultrasound activation with 42-90% product yields (Figure 13). The use of water as a solvent as well as sonification activation is part of green chemistry principles for this protocol [21].…”

Green Chemistry in Organic Synthesis: Recent Update on Green Catalytic Approaches in Synthesis of 1,2,4-Thiadiazoles

“…The concept of green chemistry introduced the environmentally benign synthetic protocols for the synthesis of heterocycles that has had a significant impact in many fields, such as the use of green solvents, solvent-free synthesis, sustainable catalytic materials, reduced energy consumption, improved atom economy, optimized reaction yields, the use of alternative energy sources, the introduction of multicomponent reactions (MCRs), ionic liquids and the design of high-efficiency and time-saving reactions that work at ambient temperatures [16][17][18][19][20][21][22][23][24][25]. Pollution and an increase in energy demands prompted the design of novel synthetic protocols to fulfill the requirements of green and sustainable chemistry to promote the synthesis of organic products in an ecofriendly environment [26,27]. The new green and sustainable synthetic approaches are listed below and have advantages over conventional synthetic approaches, as depicted in Figure 2 [28][29][30][31][32][33][34][35]:…”