This is an original work on catalytic performance of urease in organic synthesis which in one-pot dissociation of urea and condensation of the in situ generated ammonia with aldehydes, acetophenones, and malononitrile occurs in water to give 2-amino-3-cyanopyridines. Comparative experiments with ammonium salts supported the enzymatic specify of 0.01 g/mL (50 U/mg) of urease for bio-production of ammonia, while trace amount of heavy metal ions such as Pb 2+ , Hg 2+ , and Ag + inhibit these specific reactions. The scalability and promiscuity of urease facilitate the applicability of the process for biotechnological organic reactions based on ammonia.

Urease-catalyzed synthesis of aminocyanopyridines from urea under fully green conditions

New ecofriendly Biginelli reaction procedures have been adapted to prepare new dihydropyrimidines (DHPMs) using a multicomponent one-pot reaction. All the synthesized compounds were evaluated for t...

https://www.tandfonline.com/doi/pdf/10.1080/17518253.2021.1896789

Design, ecofriendly synthesis, anticancer and antimicrobial screening of innovative Biginelli dihydropyrimidines using β-aroylpyruvates as synthons

Many methods to prepare heterocyclic compounds involve toxic solvents and reagents. There is therefore a need to design cleaner synthetic procedures. 1,6-Naphthyridine derivatives are used in many applications such as cancer chemotherapy, antibacterials, antivirals and antiproliferatives. Here, we report the solvent-free and catalyst-free synthesis of 1,6-naphthyridine derivatives. Synthesis is done by grinding of 2 mmol of ketones, 2 mmol of malononitrile and 1 mmol of amines in a mortar at room temperature for 5–7 min. 1,2-Dihydro[1,6]-naphthyridine derivatives were obtained in 90–97 % yields.

Rapid synthesis of 1,6-naphthyridines by grindstone chemistry

Facile synthesis of aminoalkyl naphthols and single crystal X-ray, computational studies on 1-[morpholino(thiophen-2-yl)methyl]naphthalen-2-ol

Herein, we report the catalytic action of phosphotungstic acid - Jeffamine® hybrid (PTA-Jeffamine®) for the synthesis of dihydropyrimidinones (DHPMs) starting from benzyl alcohol by Biginelli reaction in water in a one-pot system. Hydrogen peroxide was used as oxidizing agent instead of the conventional nitrate salts. A two-step and a one-step protocol was used to evaluate the catalytic activity. Both processes showed appreciable results with the one-pot one-step protocol demonstrating appreciable yield (87 %) of DHPM within 5.5 h at pH 7.5. No acid was added and the pH was adjusted by controlling ratio of PTA/ Jeffamine®. Catalytic results were compared with literature reports for one-pot one-step Biginelli reactions starting from benzyl alcohol. Biginelli products were characterized by UV-visle–vis, FT-IR, NMR spectroscopy. DHPMs formed from the two-step process demonstrated appreciable anticancer activity. The present work may lead to the development of industry-friendly, non-toxic and scalable catalyst for one-pot Biginelli reactions.

Phosphotungstic acid - Jeffamine® hybrid catalyst for one-pot Biginelli reaction starting from benzyl alcohol

A simple, green and highly efficient procedure for the Biginelli condensation
reaction of aldehydes, β-ketoesters, urea or thiourea catalyzed by
crushed garlic clove at ambient temperature is reported.

/pdf/garlic-clove-catalyzed-biginelli-reaction-in-water-at-20h6nk8zxi.pdf

Garlic Clove Catalyzed Biginelli Reaction in Water at Ambient Temperature

Abstract Starting from readily available 2-naphthol, aldehydes, aryl and alkylamines, a variety of Betti bases were efficiently synthesized utilizing a catalytic amount of cerium (IV) ammonium nitrate (CAN) at room temperature. This protocol has advantages of high yield, mild reaction conditions, no environmental pollution, diversity of reactants and simple work up procedure.

An efficient multicomponent, one-pot synthesis of Betti bases catalyzed by cerium (IV) ammonium nitrate (CAN) at ambient temperature

Abstract An efficient one-pot multicomponent reaction of 2-aminopyridine with aromatic aldehydes and either benzoyl cyanide or cyanamide in pyridine under controlled microwave heating afforded N-aryldene-2-arylimidazo[1,2-a]-pyridine-3-ylamine derivatives. The reaction is catalyst free and is of high atom economy.

An efficient and catalyst-free synthesis of N-arylidene-2-arylimidazo[1,2-a]pyridine-3-ylamine derivatives via Strecker reaction under controlled microwave heating

Reham R. Awed

Papers

Garlic Clove Catalyzed Biginelli Reaction in Water at Ambient Temperature

An efficient multicomponent, one-pot synthesis of Betti bases catalyzed by cerium (IV) ammonium nitrate (CAN) at ambient temperature

An efficient and catalyst-free synthesis of N-arylidene-2-arylimidazo[1,2-a]pyridine-3-ylamine derivatives via Strecker reaction under controlled microwave heating