Catalyst-free synthesis of novel 4H-indeno[1,2-b]furan-4-ones and furo[2,3-d]pyrimidines in water

Aryl glyoxal: a prime synthetic equivalent for multicomponent reactions in the designing of oxygen heterocycles

The category of bifunctional building blocks overrides many others because of their fascinating wide applicability in synthetic chemistry. Aryl glyoxal is one of the key molecules that has been extensively used in heterocyclic chemistry to afford nearly all types of five- and six-membered heterocycles, which are the structural constituents of many natural products. The multicomponent reaction is a practical strategy to utilize this wonderful moiety with different types of starting materials to obtain numerous diverse oxygen heterocycles. This review covers the advancement of aryl glyoxal as a prime synthetic equivalent in recent years for the synthesis of oxygen heterocycles.

Recent Advances in the Application of Barbituric Acid Derivatives in Multicomponent Reactions

Abstract:

Barbituric acid is a pyrimidine heterocyclic organic compound, which is pharmacologically active. It is important to build structures containing various medicinal activities. This compound attracts the scientific research community in organic synthesis. It can be used in the synthesis of polyheterocyclic, natural, medicinal compounds, and organic sensors. Herein, the utilization of barbituric or thiobarbituric acid in multicomponent reactions is reported from 2016-2021 in this manuscript.

Recent Progress in the Synthesis of Heterocycles Based on 1,3-Diketones

N,O-heterocycles containing the dicarbonyl ring play a significant role in heterocyclic and therapeutic chemistry. Since the discovery of 1,3-diketones, numerous research works have been achieved regarding the synthesis and its chemical reactivity. In this review, we have described the most relevant publications involving β-diketone compounds published during the period between 2018 to date. In addition, we include the 1,3-diketones-based heterocyclic compounds prepared by various synthetic methodologies.

Green synthesis of new lawsone enaminones and their Z/E(CC)-isomerization induced by organic solvent

The synthesis of a new class of lawsone enaminone derivatives by using lawsone, triethyl orthoformate and aromatic amines in the presence of guanidinium chloride under solvent-free conditions has been developed.

Series of Functionalized 5-(2-Arylimidazo[1,2-a]pyridin-3-yl)pyrimidine-2,4(1H,3H)-diones: A Water-Mediated Three-Component Catalyst-Free Protocol Revisited

A water-mediated and catalyst-free practical method for the synthesis of a new series of pharmaceutically interesting functionalized 5-(2-arylimidazo[1,2-a]pyridin-3-yl)pyrimidine-2,4(1H,3H)-diones has been accomplished based on a one-pot multicomponent reaction between arylglyoxal monohydrates, 2-aminopyridines/2-aminopyrimidine, and barbituric/N,N-dimethylbarbituric acids under reflux conditions. The salient features of this protocol are avoidance of any additive/catalyst and toxic organic solvents, use of water as reaction medium, clean reaction profiles, operational simplicity, ease of product isolation/purification without the aid of tedious column chromatography, good to excellent yields, and high atom-economy and low E-factor.

Synthesis of indenofurans, benzofurans and spiro-lactones via Hauser–Kraus annulation involving 1,6-addition of phthalide to quinone methides

Base mediated 1,6-addition–Dieckmann cyclization of phthalide with quinone methide leads to oxygen heterocycles such as indenofurans, spiro-lactones and benzofurans through a cascade of rearrangements involving multiple ring opening and ring closure.