β-Cyclodextrin as a Biomimetic Catalyst for the Efficient Synthesis of 4-Oxo-pyrido[1,2-a] Pyrimidine-3-Carbonitrile in Aqueous Medium

A Focussed Analysis of β-cyclodextrins for Quinoxaline Derivatives Synthesis

Abstract:

Cyclodextrins (CDs), which are a type of cyclic oligosaccharides, are widely used in supramolecular chemistry. For example, they can be used to encapsulate volatile compounds, such as drugs, within their hydrophobic cavity. This encapsulation reduces the volatility of the compounds and helps to retain their desired properties. Due to its extraordinary properties, cyclodextrins have been utilized as catalysts in numerous organic synthesis processes. An intrinsic objective of organic chemists is to optimize the efficacy of organic synthesis through the mitigation of chemical waste and energy expenditure. Utilizing water as a green solvent is, therefore, economical, environmentally sustainable, and secure. It appears that employing water in conjunction with a recyclable catalyst is the most effective method for supramolecular catalysis. As a consequence, we focused this review on the use of water as a solvent and cyclodextrin as a polymer catalyst to produce quinoxaline derivatives in an environmentally friendly and sustainable manner.

β-Cyclodextrin: a green supramolecular catalyst assisted eco-friendly one-pot three-component synthesis of biologically active substituted pyrrolidine-2-one

A green, novel and eco-efficient synthetic route towards the synthesis of highly substituted bio-active pyrrolidine-2-one derivatives was demonstrated using β-cyclodextrin, a water-soluble supramolecular solid as a green and eco-benign catalyst at room temperature under water-ethanol solvent medium. The exploration of the green catalyst β-cyclodextrin for the metal-free one-pot three-component synthesis of a wide range of highly functionalized bio-active heterocyclic pyrrolidine-2-one moieties from easily available aldehydes and amines explains the superiority and uniqueness of this protocol.

Ultrasound-assisted synthesis of pyrimidines and their fused derivatives: A review

The pyrimidine scaffold is present in many bioactive drugs; therefore, efficient synthetic routes that provide shorter reaction times, higher yields, and site-selective reactions are constantly being sought. Ultrasound (US) irradiation has emerged as an alternative energy source in the synthesis of these heterocyclic scaffolds, and over the last ten years there has been a significant increase in the number of publications mentioning US in either the construction or derivatization of the pyrimidine core. This review presents a detailed summary (with 140 references) of the effects of US (synergic or not) on the construction and derivatization of the pyrimidine core through classical reactions (e.g., multicomponent, cyclocondensation, cycloaddition, and alkylation reactions). The main points that were taken into consideration are as follows: chemo- and regioselectivity issues, and the results of conventional heating methods compared to US and mechanistic insights that are also presented and discussed for key reactions.

β-Cyclodextrin: a supramolecular catalyst for metal-free approach towards the synthesis of 2-amino-4,6-diphenylnicotinonitriles and 2,3-dihydroquinazolin-4(1H)-one

β-Cyclodextrin, a green and widespread supramolecular catalyst, has been explored as a highly proficient promoter for the metal-free one-pot multi-component synthesis of a vast range of highly functionalized bioactive heterocyclic moiety, 2-amino-4,6-diphenylnicotinonitriles and 2,3-dihydroquinazolin-4(1H)-one, from easily available precursor aldehydes. The main endeavor of these protocols is to explore this organic supramolecule in one-pot multi-component synthesis. Absence of metal catalyst or toxic acid and harsh reaction conditions, excellent functional group tolerance, inexpensive, greener and environmentally safe protocol are the key advantages of this work.

DIPEAc promoted one-pot synthesis of dihydropyrido[2,3-d:6,5-d′]dipyrimidinetetraone and pyrimido[4,5-d]pyrimidine derivatives as potent tyrosinase inhibitors and anticancer agents: in vitro screening, molecular docking and ADMET predictions

Efficient and rapid synthesis of 18 tyrosinase inhibitors with good to moderate anticancer activity and good oral drug like properties.