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An efficient InCl3-catalyzed sequential reaction of aromatic amines, aromatic aldehydes and functionalized alkynes leading to the formation of new quinoline derivatives exhibiting significant fluorescence activities is described. The photophysical investigations of quinolines were carried out by absorption and photoluminescence measurements. One particular compound 4 h having maximum intensity, emitting green colour (Φ = 0.78) with average life time of 6.20 ns was the best amongst the tested compounds. The presence of the amino group at the 4-aryl substituent of the quinoline backbone played an important role in executing the Povarov cyclization successfully and enhancing the flourescence properties of the newly synthesized quinolines. Supplementary Information The online version contains supplementary material available at 10.1007/s10895-020-02647-3.

An efficient deep eutectic solvent (DES) promoted reaction of 2-amino-5-chlorobenzophenone, aromatic aldehydes (benzoyl alcohols) and ammonium acetate leading to the formation of quinazolines with excellent yields is described. The use of expensive catalysts and organic solvents are avoided in this protocol with the use of DES, which is biodegradable and renewable.

An efficient and facile synthesis of spirooxindole derivatives bearing pyrano[2,3-c]pyrazole moiety has been achieved using deep eutectic solvent (DES) promoting a four-component reaction. The protocol avoids the use of costly and toxic catalysts and organic solvents which encounters many side effects on the environment and human beings. The simplicity and versatility of this eco-friendly green method is described. Deep eutectic solvent (DES) promoted eco-friendly synthesis of spirooxindole derivatives involving a four-component reaction is described in this article. This procedure is highly sustainable because of the involvement of readily available and biodegradable deep eutectic solvent as a reaction medium and promoter.

Synthetic application of Silica–ZnCl2 , as an efficient and eco-friendly catalyst for the synthesis of a small library of dihydropyrimidinones is described in this report. The reaction involves a one pot, multicomponent reaction of β-oxodithiocarboxylates, aldehydes, and urea under solvent-free conditions. The experimental procedure is simple, environmental benign, tolerated with many functional groups, and results in good to excellent yield of the products.

The cycloannulation of β-oxodithioesters and tryptamine in dichloromethane in the presence of a catalytic amount of InCl3 and TFA gave the novel 5-aryl/heteroaryl 2a(1),9b-dihydro-1H-2a,5a-diaza-cyclopenta[jk]fluorene-3(2H)-thiones in moderate to good yields. The reaction was proposed to involve a tandem transformation of thioamide, protonation, and dehydrative cyclization. KMnO4-oxidation of these newly prepared compounds yielded oxidative desulfurization products in good yields.

Stannous chloride, an inexpensive mild Lewis acid has been used in various organic synthetic operations. It was used in reducing various functional groups in the earlier days. The recent trends however expanded the scope of its applications in organic synthesis using it as an efficient catalyst. This review highlights the catalytic potential of this rea- gent in a wide range of reactions such as allylation, propargylation, multicomponent reactions and syntheses of bioactive heterocycles.

Transesterification of β-oxodithioesters catalyzed by stannous chloride under solvent-free condition has been reported for the first time. The short reaction time and good to excellent yields using inexpensive catalysts are attractive features of this synthetic protocol.

A facile synthesis of chromene-2-thiones by the Pechmann condensation of phenols and β-oxodithioesters catalyzed by AlCl 3 under solvent-free condition has been reported. The best results were obtained in the case of substituted phenols such as resorcinol, substituted resorcinol, and pyrogallol. The optimum condition was observed with the use of 10 mol % of AlCl 3 at 130 °C under solvent-free conditions. This method offers a wide scope for the synthesis of coumarins in good yields during a short period of time.

Synthetic application of Silica–ZnCl2 , as an efficient and eco-friendly catalyst for the synthesis of a small library of dihydropyrimidinones is described in this report. The reaction involves a one pot, multicomponent reaction of β-oxodithiocarboxylates, aldehydes, and urea under solvent-free conditions. The experimental procedure is simple, environmental benign, tolerated with many functional groups, and results in good to excellent yield of the products.

A highly efficient method of synthesis of S-allyl-N-aryl dithiocarbamates using SnCl2 as a catalyst under solvent-free conditions is described. The mild reaction conditions, high yields, and shorter reaction period illustrate the good synthetic utility of this method.

The reactions of ketene dithioacetals with ethane-1,2-diamine, propane-1,3-diamine, 2-aminoethanol, 3-aminopropanol, and 2-aminoethanethiol in ordinary water in the absence of any acid/base catalyst afforded the heterocyclic ketene N,N-, N,O- and N,S-acetals in good yields.

Regioselective allylation of enaminones using CuCl 2 as the catalyst to give C-allylated products is reported for the first time. The C-allylated products undergo hydrolysis followed by a rearrangement yielding β-keto allyl enamides in excellent yields.

Stannous chloride, an inexpensive mild Lewis acid has been used in various organic synthetic operations. It was used in reducing various functional groups in the earlier days. The recent trends however expanded the scope of its applications in organic synthesis using it as an efficient catalyst. This review highlights the catalytic potential of this rea- gent in a wide range of reactions such as allylation, propargylation, multicomponent reactions and syntheses of bioactive heterocycles.

The cycloannulation of β-oxodithioesters and tryptamine in dichloromethane in the presence of a catalytic amount of InCl3 and TFA gave the novel 5-aryl/heteroaryl 2a1,9b-dihydro-1H-2a,5a-diaza-cycl...

Notable features of the protocol include a short reaction time, mild conditions, and the use of an inexpensive catalyst.

A facile synthesis of chromene-2-thiones by the Pechmann condensation of phenols and β-oxodithioesters catalyzed by AlCl 3 under solvent-free condition has been reported. The best results were obtained in the case of substituted phenols such as resorcinol, substituted resorcinol, and pyrogallol. The optimum condition was observed with the use of 10 mol % of AlCl 3 at 130 °C under solvent-free conditions. This method offers a wide scope for the synthesis of coumarins in good yields during a short period of time.

The procedure is highly efficient in the case of primary aliphatic amines and no catalyst is necessary.

A highly efficient method of synthesis of S-allyl-N-aryl dithiocarbamates using SnCl2 as a catalyst under solvent-free conditions is described. The mild reaction conditions, high yields, and shorter reaction period illustrate the good synthetic utility of this method.

A facile route to hitherto unknown 5-methylmercaptothiocarbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones and substituted 2H-chromene-2-thiones has been developed. SnCl(2)-catalyzed cyclocondensation of beta-oxodithioesters with a variety of readily accessible aldehydes and urea affords the dihydropyrimidinones. The methodology involves the three-component Biginelli reaction. On the other hand, substituted salicylaldehyde and beta-oxodithioesters reacted under the same condition to afford the substituted 2H-chromene-2-thiones in high yields.

Regioselective allylation of enaminones using CuCl 2 as the catalyst to give C-allylated products is reported for the first time. The C-allylated products undergo hydrolysis followed by a rearrangement yielding β-keto allyl enamides in excellent yields.

Copper (II) chloride in the absence of any solvent, efficiently catalyses the synthesis of dihydropyrimidinones (80-96% yields) by the Biginelli reaction. Six compounds were selected and examined their antifungal activities against the radial growth of three fungal species viz., Trichoderma hammatum, Trichoderma koningii and Aspergillus niger.

A new general route for the title olefins 5a-e, 12, 13, 8a-e and 11a-e has been developed through nucleophilic addition of respective Grignard reagents i.e. allyl-, benzyl-, 1-(naphthylmethyl) magnesium halides to 5-aryl- 1,1-bis(methylthio)pent-4-en-3-ones, 7-aryl-1,1-bis(methylthio)hepta-4,6-dien-3-ones and 9-phenyl-1, 1-bis(methylthio)nona-4,6,8-trien-3-one followed by cycloaromatization of the resulting 3-substituted 1,1-bis(methylthio)alken-3-ols in the presence of boron trifluoride-diethyl ether complex.