The tert-butyloxycarbonyl (Boc) group is one of the most widely used amine-protecting groups in multistep reactions synthetic organic chemistry as well peptide synthesis. Traditional methods to remove Boc have disadvantages terms high acidity, use expensive reagents, excessive amounts catalysts and harmful solvents temperatures, making them environmentally unsustainable. Therefore, more efforts...

This article describes the synthesis of a library of structurally diverse bifunctional organocatalysts bearing both a quasi-Lewis acidic (thio)urea moiety and a Brønsted basic tertiary amine group. Sequential modification of the modular catalyst structure and subsequent screening of the compounds in the alcoholytic dynamic kinetic resolution (DKR) of azlactones revealed valuable structure-activ...

We report here an efficient and green method for Biginelli condensation reaction of aldehydes, β-ketoesters and urea or thiourea catalyzed by Brønsted acidic ionic liquid [Btto][p-TSA] under solvent-free conditions. Compared to the classical Biginelli reaction conditions, the present method has the advantages of giving good yields, short reaction times, near room temperature conditions and the ...

An efficient synthesis of novel 3,4-dihydropyrimidin-2(1H)-ones (DHPMs) and their derivatives, using Brønsted acidic ionic liquid [C₂O₂BBTA][TFA] as a catalyst, from the condensation of aryl aldehyde, β-ketoester and urea was described. Reactions proceeded smoothly for 40 min under solvent-free conditions and gave the desirable products with good to excellent yields (up to 99%). The catalyst co...

Pyrido[2,3-d]pyrimidine derivatives were synthesized regioselectivly in good to high yields by one-pot three-component condensation of 6-amino-2-(methylthio)pyrimidin-4(3H)-one, aromatic aldehydes and ethylcyanoacetate or meldrum's acid using 1,2-dimethyl-N-butanesulfonic acid imidazolium hydrogen sulfate ([DMBSI]HSO4) Brønsted-acidic ionic liquid as catalyst. Solvent-free mild reaction conditi...

In this paper, we introduce Brønsted acidic ionic liquid (BAIL), (4-sulfobutyl) tris (4-sulfophenyl) phosphonium hydrogen sulfate as a green and efficient catalyst for the synthesis of 2,3-disubstituted quinoxaline derivatives via the one-pot condensation reaction of various o-phenylenediamine with 1,2-diketone derivatives. At all experiments, the desired products were synthesized successfully....

Reaction kinetics were studied to quantify the effects of polar aprotic organic solvents on the acid-catalyzed conversion of xylose into furfural. A solvent of particular importance is γ-valerolactone (GVL), which leads to significant increases in reaction rates compared to water in addition to increased product selectivity. GVL has similar effects on the kinetics for the dehydration of 1,2-pro...

The Brønsted acidic ionic liquid ([BMIm]HSO4) catalyzed three-component synthesis of 2H-indazolo[2,1-b]phthalazine-trione derivatives at room temperature. The integrity of the ionic liquid remains reasonably unchanged when it is separated from the reaction mixture by water extraction, as it can be recycled several times without any loss of activity in each of the title syntheses. The products a...

Catalysts obtained by the immobilisation of acidic ionic liquids (ILs) on solid supports offer several advantages compared to the use of catalytically active ILs themselves. Immobilisation may result in an increase in the number of accessible active sites of the catalyst and a reduction of the amount of the IL required. The ionic liquid films on the carrier surfaces provide a homogeneous enviro...