ZrOCl2·8H2O: an efficient Lewis acid catalyst for the one-pot multicomponent synthesis of β-acetamido ketones

Aromatic aldehydes were reacted in one-pot with enolisable ketones, acetonitrile and acetyl chloride at ambient temperature in the presence of ZrOCl₂·8H₂O to furnish the corresponding β-acetamido ketones in very good to excellent yields. X-ray crystallographic analysis of one anti-β-acetamido ketone exhibited a two-dimensional supramolecular framework by a combination of N-H?O, C-H?O and C-H?π (arene) hydrogen bonds.     

Highly efficient synthesis of homoallylic alcohols and amines via allylation of aldehydes and imines catalyzed by ZrOCl2·8H2O in water

The allylation of aldehydes and imines has efficiently been carried out by treatment with allyltributylstannane in the presence of a catalytic amount of ZrOCl₂·8H₂O in water to form the corresponding homoallylic alcohols and amines, respectively, in high yields.     

ZrOCl2·8H2O mediated microwave induced [3+2] cycloaddition of azomethine ylides—a facile one-pot synthesis of novel dispiroheterocycles

An efficient microwave-assisted, ZrOCl₂·8H₂O mediated, synthesis of novel dispiro-oxindolopyrrolidines and -pyrrolizidines was accomplished through [3+2] cycloaddition reaction of azomethine ylides derived from acenaphthenequinone and sarcosine/l-proline with (E)-2-oxoindolino-3-ylidene acetophenones in good yields.     

Efficient one-pot synthesis of functionalized piperidine scaffolds via ZrOCl2·8H2O catalyzed tandem reactions of aromatic aldehydes with amines and acetoacetic esters

A highly efficient diastereoselective one-pot synthesis of functionalized piperidines has been developed based on an aqua-compatible ZrOCl₂·8H₂O catalyst via tandem reactions of aromatic aldehydes, amines, and acetoacetic esters.     

Zn(OAc)2·2H2O: a versatile catalyst for the one-pot synthesis of propargylamines

An inexpensive and readily available catalyst, Zn(OAc)₂·2H₂O is successfully evaluated for effective one-pot synthesis of propargylamines with moderate to excellent yields for most of the substrates screened, without the need of base, co-catalyst or additive in the presence of air.     

An efficient and one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by InCl3·3H2O

InCl₃·3H₂O was found to be a mild and effective catalyst for the efficient, one-pot, three component synthesis of 2,4,5-trisubstituted imidazoles at room temperature. Moreover, the utility of this protocol was further explored conveniently for the one-pot, four component synthesis of 1,2,4,5-tetrasubstituted imidazoles in high yields.     

CeCl3·H2O/NaI-Promoted stereoselective synthesis of 2,4-disubstituted chiral tetrahydroquinolines

d-Glycals readily undergo cyclization with aryl amines in the presence of CeCl₃·7H₂O-NaI under mild and neutral conditions to afford a novel sugar derived tetrahydroquinoline derivatives in good yields with high stereoselectivity. The stereochemistry of the products was assigned by using various NMR studies.     

A facile one-pot procedure for the transformation of acetonides into diacetates catalyzed with Bi(OTf)3·xH2O

The transformation of acetonides into the corresponding diacetates is often required in the synthetic chemistry. An efficient procedure for direct conversion of acetonides into diacetates in the presence of Bi(OTf)₃·xH₂O under mild conditions has been developed. Primary hydroxyl-acetonides could be selectively transformed into diacetates in the presence of anomeric acetonides and the anomeric acetonides could be tunably converted into 2-acetoxyisopropyl or diacetate groups.     

RuCl3·3H2O as catalyst for Ferrier rearrangement: an efficient procedure for the preparation of pseudoglycosides

By using RuCl₃·3H₂O as catalyst, an improved method for the synthesis of 2,3-unsaturated-glycosides has been established. A series of 2, 3-unsaturated-glucosides were obtained from 2,4,6-tri-O-acetyl-d-glucal or 3,4-di-O-acetyl-6-deoxy-l-glucal in good yield and high anomeric selectivity.     

ZrOCl2·8H2O on montmorillonite K10 accelerated conjugate addition of amines to α,β-unsaturated alkenes under solvent-free conditions

At room temperature, ZrOCl₂·8H₂O on montmorillonite K10 efficiently catalyzes conjugate addition of amines to a variety of conjugated alkenes such as α,β-unsaturated carbonyl compounds, carboxylic esters, nitriles and amides under solvent-free conditions. The catalyst can be recycled for subsequent reactions without any appreciable loss of efficiency.     

Facile catalyzed acylation of alcohols, phenols, amines and thiols based on ZrOCl2·8H2O and acetyl chloride in solution and in solvent-free conditions

Acylation of heteroatoms (O, N and S) with acetyl chloride based on the use of a catalytic amount of the moisture stable, inexpensive ZrOCl₂·8H₂O, proceeds efficiently producing the corresponding acylated products in excellent yields.     

A simple,efficient thermally promoted protocol for Huisgen-click reaction catalyzed by CuSO4·5H2O in water

A thermally promoted and CuSO₄-catalyzed new version of the Huisgen-click reaction is presented in this Letter. Notably, this protocol was suitable not only for the reactions between organic azides and alkynes, but also for one-pot three-component reactions among alkyl halides, NaN₃, and alkynes.     

An efficient synthesis of unsymmetrical diarylmethanes from the dehydration of arenes with benzyl alcohols using InCl3·4H2O/acetylacetone catalyst system

An efficient and practical synthesis of unsymmetrical diarylmethanes has been achieved from the dehydration of arenes with benzyl alcohols in the presence of catalytic amount of InCl₃·4H₂O/acetylacetone.     

A mild and efficient acetylation of alcohols, phenols and amines with acetic anhydride using La(NO3)3·6H2O as a catalyst under solvent-free conditions

A wide variety of alcohols, phenols and amines are efficiently and selectively converted into the corresponding acetates by treatment with acetic anhydride in the presence of catalytic amounts of La(NO₃)₃·6H₂O under solvent-free conditions at room temperature. The method is compatible with acid sensitive hydroxyl protecting groups such as TBDMS, THP, OBz, OBn, Boc and some isopropylidenes and offers excellent yields of the mono acetates of 1,3-, 1,4- and 1,5-diols.     

An efficient and simple method for synthesis of 2,2-disubstituted-2H-chromenes by condensation of a phenol with a 1,1-disubstituted propargyl alcohol using BF3·Et2O as the catalyst

An efficient and simple method for the synthesis of 2,2-disubstituted-2H-chromenes by one-step cyclocondensation of a phenol with a variety of 1,1-disubstituted propargyl alcohols using BF₃·Et₂O as the catalyst is described.     

Y(NO3)3·6H2O catalyzed regioselective ring opening of epoxides with aliphatic, aromatic, and heteroaromatic amines

Yttrium nitrate hexahydrate [Y(NO₃)₃·6H₂O] was found to be an efficient catalyst for selective ring opening of epoxides with aliphatic, aromatic, and heteroaromatic amines at room temperature under solvent-free conditions. The system tolerated a variety of hindered and functionalized epoxides/amines and afforded the desired β-amino alcohols at low catalyst concentration.     

Cupric sulfate pentahydrate (CuSO4·5H2O): a mild and efficient catalyst for tetrahydropyranylation/depyranylation of alcohols and phenols

Various alcohols and phenols can be smoothly converted to the corresponding THP ethers using 20 mol % CuSO₄·5H₂O under mild reaction conditions at room temperature. Some of the major advantages of this procedure are nonaqueous work-up, very good yields, less expensive catalyst and compatibility with other protecting groups.     

Ultrasound-promoted synthesis of 2-amino-6-(arylthio)-4-arylpyridine-3,5-dicarbonitriles using ZrOCl2·8H2O/NaNH2 as the catalyst in the ionic liquid [bmim]BF4 at room temperature

We herein present an efficient and environmentally benign protocol for the synthesis of 2-amino-6-(arylthio)-4-arylpyridine-3,5-dicarbonitrile derivatives via the three-component condensation of a variety of aldehydes, arylthiols, and malononitrile catalyzed by ZrOCl₂·8H₂O/NaNH₂ (20 mol %) in the ionic liquid [bmim]BF₄ under ultrasound irradiation at room temperature.     

FeCl3·6H2O oxidation of protected resveratrol for the synthesis of tetraarylfuran-type oligostilbenes

Several 8-8-coupled tetraarylfuran-type oligostilbenes were prepared through FeCl₃·6H₂O-catalyzed regioselective oxidative couplings of protected resveratrol precursors. The global deprotection of the coupling dimers in a one-pot reaction yielded (±)-pallidol instead of the targets (±)-restrytisol B and (±)-tricuspidatol A.     

Facile N-tert-butoxycarbonylation of amines using La(NO3)3·6H2O as a mild and efficient catalyst under solvent-free conditions

Facile N-tert-butoxycarbonylation of amines is described by the treatment of various primary, secondary, benzylic and aryl amines with di-tert-butyl dicarbonate in the presence of catalytic amounts of La(NO₃)₃·6H₂O under solvent-free conditions at room temperature to afford N-tert-butylcarbamates in excellent yields.