Organic Chemistry Research
Volume:5 Issue: 2, Autumn 2019

Reduction of aldehydes and ketones to the corresponding alcohols in the presence of sodium cyanoborohdride as reductive agent and Tonsil clay as catalyst under solvent free conditions was investigated. Tonsil (catalyst) decreased the reduction time of each aldehyde and ketone to proportional alcohols in comparison with their reduction in the absence of catalyst with high degree purity of alcohols. Reduction reactions were carried out in solvent free condition in less than 15 minutes at room temperature. All obtained alcohols from reduction of related carbonyl compounds were detected by FT-IR and 1H/13C NMR spectra.

In this paper, the applicability of immobilized lanthanum (III) triflate on amine grafted graphene oxide [La(OTf)2-amine grafted-GO] as the first multifunctional catalyst is described for the efficient synthesis of α-aminophosphonates by one-pot three-component reaction of carbonyl compounds, substituted anilines and trialkyl phosphites. Various α-aminophosphonates were synthesized in good to high yields under solvent-free conditions at room temperature. The catalyst was reused five times without significant loss of its activity.

A new, efficient and mild approach for the oxidative dehydrogenation of dihydropyrimidinones and thiocyanation of aromatic compounds using 1,1,2,2-tetrahydroperoxy-1,2-diphenylethane (THPDPE) as a terminal oxidant was developed. Initially, various substrates bearing different electron-donating and electron-releasing functionalities were synthesized and next under the optimized reaction conditions the desired products were yielded after an easy work-up and the structures were characterized compared with those reported. All of the reactions proceeded in short reaction times and 1,1,2,2-tetrahydroperoxy-1,2-diphenylethane (THPDPE) proved its potential to yield the desired products in high yields.

A facile synthesis of highly functionalized 2H-iminopyran derivatives by the multi-component reaction of cyclohexyl isocyanide, dialkyl acetylenedicarboxylates, arylglyoxals and arylamines is described. The zwitterionic intermediate produced by addition of cyclohexyl isocyanide to electron-deficient acetylene diesters was trapped by the electrophilic imine moiety of α-iminoketones, derived from arylglyoxals and arylamines, to afford an inner salt intermediate which converted to 2H-iminopyran derivatives by an intramolecular cyclization.

N1,N1,N2,N2-tetramethyl-N1,N2-bis(sulfo)ethane-1,2-diaminium chloride ([TMBSED][Cl]2) was synthesized as an acidic ionic liquid and characterized using FT-IR, 1H and 13C NMR, mass spectroscopy, TG, DTG and DTA techniques. This ionic liquid was employed as efficient catalyst for the extremely facile and efficient synthesis of dihydropyrrol-2-ones and functionalized tetrahydropyridines. One-pot four-component reaction of amines, dialkyl acetylenedicarboxylates and formaldehyde in the presence of [TMBSED][Cl]2 in ethanol at ambient temperature provides substituted dihydropyrrol-2-ones in good to high yields. This ionic liquid catalyst was also found useful for the synthesis of functionalized tetrahydropyridines using a multi-component reaction of amines, aldehydes and β-ketoesters in methanol.the formula is not displayed correctly!

An aqueous solution of boric acid, as an efficient and green catalytic system, was efficiently utilized four-component cascade reaction of aryl aldehydes, dimedone, β-ketoesters and ammonium acetate to give hexahydroquinolines. By the reaction of boric acid with water, H+ was generated and efficiently catalyzed the reaction under mild and green condition. Also, optimization of the reaction condition was investigated using the response surface method {Central Composite Design (CCD)}.

A new and imaginative technique for the synthesis of substituted pyranoquinoline via Algar Flyn Oyamanda oxidation cyclization approach has been achieved by hydrogen peroxide and sodium hydroxide catalyzed of quinoline chalcone with intramolecular cyclization to formed pyranoquinoline. In this reaction, two new C-C bonds were formed in a one step with high atom economy. The possible reaction pathway for the formation of the products was also discussed in greener technique this paper.

A convenient method for the synthesis of 5-substituted-1H-tetrazoles from organic nitriles and sodium azide in the presence of nano silica melamine trisulfonic acid is reported. A series of aliphatic and aromatic nitriles were underwent a [3+2] cycloaddtion with sodium azide to afford tetrazoles in good to excellent yields and acceptable reaction times. The nano silica melamine trisulfonic acid is an efficient heterogeneous nanocatalyst with high catalytic performance. The nano silica melamine trisulfonic acid is readily prepared, environmentally friendly and reusable. The catalyst was characterized by Powder X-ray diffraction, energy-dispersive X-ray mapping and SEM techniques. The procedure was simple, cost effective that holds potential for further applications in organic syntheses and industrial requirements.

In the recent decades, development of green and reliable processes for synthesis of metallic nanoparticles is inevitable because of their important applications in all fields of science, especially in nanotechnology and industry. Biological systems have received great attentions from scientist due to low cat, green nature and simple process for synthesis of metallic NPs. In this research, metal nanoparticles, Ag and Fe3O4 NPs, were synthesized through an ecofriendly and cost effective approach using aqueous extract of Cleome heratensis (C. heratensis). The influence of effective parameters including pH, interaction time, temperature, plant extract concentration and Ag concentration were thoroughly investigated base on surface plasmon resonance (SPR) for Ag NPs at max  470 nm. The bio-synthesized NPs were characterized by FTIR, UV-Vis, XRD, TEM and VSM analyses. The TEM images showed the size of silver and magnetite nanoparticles as 12.27 and 14.12 nm respectively with a homogeneous distribution and nearly spherical in shape.

 In this research, new derivatives of poly (propylene imine) dendrimer were synthesized using propylamine and ethylenediamine. First, amines via aza-Micheal addition reacted with methyl acrylate, then their products were affected treated with poly (propylene imine) dendrimer (PPI). The products were identified by FT- IR, 1 HNMR and 13CNMR methods. Morphology and size of particles were evaluated by scanning electron microscopy.

Three components one-pot Mannich reaction of ketone, aromatic aldehyde and aromatic amines has been efficiently catalyzed by recyclable and heterogeneous L-Cysteine supported on ZnS nanoparticles at ambient temperature to give various β-amino carbonyl compounds with high yields. This simple method has some advantages such as mild condition and no environmental pollution. Structures of the compounds were confirmed by 1H NMR and IR spectral analyses. ZnS nanoparticles were prepared in hydrothermal procedure from an aqueous solution of Zinc acetate and NaS in the presence of L-Cysteine. L-Cysteine supported on ZnS nanoparticles was characterized by FT-IR, TEM, TGA/DTA and XRD analysis.

With the aim of developing an efficient and eco-friendly method for a diastereoselective synthesis of dispiro[tetrahydroquinoline-bis(2,2-dimethyl[1,3] dioxane-4,6-dione)] derivatives, a one-pot pseudo-eight-components reaction between arylamines, aromatic aldehydes and Meldrum’s acid has occurred in the presence of lactic acid as catalyst. The salient aspects of this protocol are, operational simplicity, facile product separation, a cheap and eco-friendly catalyst, clean reaction conditions, absence of any hazardous organic solvent and moderate to high yields.