Dhruva Kumar

Efficient, Solvent-Free, Microwave-Enhanced Condensation of 5,5-Dimethyl-1,3-cyclohexanedione with Aldehydes and Imines Using LiBr as Inexpensive, Mild Catalyst

Efficient, solvent-free, microwave-enhanced condensation of 5,5-dimethyl-1,3-cyclohexanedione with aldehydes using LiBr as catalyst affords xanthenediones. Imines gave only bis-5,5-dimethyl-1,3-cyclohexanediones at high power; a slightly longer period gave xanthenediones. In both types of reactions, the products are obtained in very good to excellent yields. The present protocol is inexpensive and ecofriendly.

New Efficient Protocol for the Production of Hantzsch 1,4-Dihydropyridines Using RuCl3

Abstract Hantzsch 1,4-dihydropyridines are synthesized in a few minutes and in good to excellent yields from aldehydes, 1,3-dicarbonyl compounds, and ammonium acetate. The reaction is performed in solvent-free conditions, and 5 mol% of RuCl3 is enough for this protocol.

Multicomponent eco-friendly synthesis of 3,4-dihydropyrimidine-2-(1H)-ones using an organocatalyst Lactic acid

Abstract Biginelli compounds 3,4-dihydropyrimidine-2-(1H)-ones are synthesized in high yields via eco-friendly simple reaction procedure using Lactic acid: organocatalyst. The new method reported herein is green and is free of formation of any hazardous by products. The process has significant advantages over other reported methods.

Bismuth(III) Chloride–Mediated, Efficient, Solvent-Free, MWI-Enhanced Doebner Condensation for the Synthesis of (E)-Cinnamic Acids

A bismuth(III) chloride–mediated green process for the production of (E)-cinnamic acid derivatives using microwave irradiation under solvent-free conditions is described. The (E)-cinnamic acids are obtained in excellent yields. This protocol is green because it employs an established environmentally benign procedure, microwave irradiation. Solvent vapor pollution is not there because it is solvent free, and bismuth(III) chloride is an established nontoxic catalyst.

An efficient green protocol for the synthesis of chalcones by a Claisen–Schmidt reaction using bismuth(III)chloride as a catalyst under solvent-free condition

Abstract An environmentally benign protocol for the synthesis of chalcones by the Claisen–Schmidt condensation of aldehydes with ketones using eco-friendly non-toxic bismuth(III)chloride catalyst under solvent-free condition is reported. In this protocol, the reaction time is very short, yields are high, and there are no other pollutants formed.

Aldonitrones as Aldehyde Equivalents: An Efficient, Green, and Novel Protocol for the Synthesis of 1,8-Dioxo-octahydroxanthenes

Abstract A novel, self-catalyzed, solvent-free, microwave-enhanced, green, and efficient protocol for the synthesis of 1,8-dioxo-octahydroxanthenes and bis-5,5-dimethyl-1,3-cyclohexanediones by condensing aldo-nitrones (imine oxide) and dimedone (5,5-dimethyl-1,3-cyclohexanedione) under microwave irradiation is disclosed. Product formation (viz. xanthenes and bis-5,5-dimethyl-1,3-cyclohexanediones) is dependent on reaction conditions. The entire process is green and sustainable in terms of solvents, chemicals, reaction procedure, and yields. A plausible reaction mechanism of this reaction is also proposed. Supplementary materials are available for this article. Go to the publishers online edition of Synthetic Communications® for full experimental and spectral details. GRAPHICAL ABSTRACT

Catalyst-free synthesis of highly biologically active 5-arylidene rhodanine and 2,4-thiazolidinedione derivatives using aldonitrones in polyethylene glycol.

A green, efficient synthesis of 5-arylidene rhodanine and 2,4-thiazolidinedione derivatives without using any external catalyst in polyethylene glycol (PEG) at 80°C has been described. Reaction procedure is very simple, short, and obtained yields are very high.