One-pot conversion of carbamates of unsaturated β-aminoesters into unsaturated β-lactams by use of trimethylsilyl iodide

Trimethylsilyl iodide (TMSI) is introduced as an efficient reagent for the one-pot and direct transformation of carbamates of unsaturated β-aminoesters into the corresponding α-methylene-β-lactams and α-arylidene-β-lactams. The mild reaction conditions, excellent yields and easy work-up procedures make it a useful alternative to previously applied procedures for the rapid synthesis of β-lactams from easily available Baylis-Hillman adducts.     

One-pot synthesis of novel pyrido[2,3-d]pyrimidines using HAp-encapsulated-γ-Fe2O3 supported sulfonic acid nanocatalyst under solvent-free conditions

Novel pyrido[2,3-d]pyrimidine derivatives were synthesized through a one-pot three-component approach using HAp-encapsulated-γ-Fe2O3[γ-Fe2O3@HAp-SO3H]catalyzed condensation of 6-arnino-2-（methylthio or ethylthio）pyrimidin-4（3H）-one,Meldrum＇s acid and aryl aldehydes at 60 ℃ and under solvent-free conditions.In this protocol the use of nanocatalyst provided a green,useful and rapid method to generate the products in short reaction times and excellent yields（88%-94%）.     

Novel,One-Pot,Three-Component,Regioselective Synthesis of Fluorine-Containing Thiazole and Bis-3H-thiazole Derivatives Using Polyvinyl Pyridine as Heterogeneous Catalyst,and Evaluation of Their Antibacterial Activity

A convenient, one-pot, three-component regioselective synthesis of novel 2,2′-(1,4-phenylene)-bis-(3-aryl-2-substituted imino-4-aryl-3H-thiazole) derivatives from 1,4-phenylene diisothiocyanate, aryl amines, and various phenacyl bromide, and also the regioselective synthesis of 3-alkyl-2-(aryl imino)-4-cyclopropyl-5-(2′-fluorophenyl)-thiazole derivatives from alkylisothiocyanate, aryl amines, and 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone in the presence of poly-4-vinyl pyridine as heterogenous basic catalyst are described. This efficient method produced the products at room temperature with excellent yields (82–96%). The structures of all products were characterized by spectral and elemental analyses. The antimicrobial activity of the synthesized compounds was evaluated against Salmonella enterica, Micrococcus luteus, Bacillus subtilis, and Pseudomonas aeruginosa.     

Studies on the Synthesis and Dynamic NMR Properties of 2-(Benzylidene amino)-N-[(R)-2-hydroxy-2-methyl-1-phenylpropyl]acetamide

An efficient method was employed for the preparation of 2-(benzylideneamino)-N-[(R)-2-hydroxy-2-methyl-1-phenylpropyl] acetamide utilizing optically pure (R)-5,5-dimethyl-4-phenyloxazolidin-2-one. This product showed interesting dynamic NMR properties for the methylene protons adjacent to the azomethine group (ΔG^? = 15.1 ± 0.1 kcal mol^-1).     

Photochromic behavior of several new synthesized dyes via Zincke salts

Synthesis of several ‘dyes’, analogs of retinal imine visual pigment via nucleophilic attack of some secondary amines to pyridinium salts following precyclic ring‐opening reaction, is discussed. The photochromic properties of these dyes have been studied by UV‐Vis spectroscopy under irradiation of UV light. Copyright © 2009 John Wiley & Sons, Ltd.     

An Expedient Synthesis of Novel Derivatives of Pyrido[2,3‐d]pyrimidines Using Magnetically Supported ZrO2 Nanocatalyst

An efficient synthesis of pyrido[2,3‐d]pyrimidine derivatives via one‐pot multicomponent reactions of 6‐amino‐2‐(alkylthio)pyrimidin‐4(3H)‐one, 3‐cyanoacetylindole and arylaldehydes using [Fe₃O₄@ZrO₂] as magnetically recyclable nanocatalyst is reported. This protocol furnished the desired products in good to excellent yields (70–93 %) and lower reaction times. The catalyst could be easily and efficiently separated from the final product solution by an external magnet and be reused in 5 consecutive runs without any significant activity decrease.     

Basic Ionic Liquid as Catalyst and Reaction Media for the One‐pot Three‐component Regioselective Synthesis of Various Thiazol‐2‐imine Derivatives

Thiazol‐2‐imine derivatives were synthesized in an easy and efficient route from the regioselective one‐pot three‐component reaction of aryl amine, alkylisothiocyanate, and various α‐haloketones in [omim][OH] basic ionic liquid. Recyclable reaction media, catalyst free, and short reaction times are the main advantages of this protocol. This method produces the products at room temperature in excellent yields (68–96%). Furthermore, the target compound 6b was determined by X‐ray crystallographic analysis.     

An efficient regioselective sonochemical synthesis of novel 4-aryl-3-methyl-4,5-dihydro-1H-pyrazolo[3,4-b]pyridin-6(7H)-ones

An efficient ultrasound-assisted preparation of a series of novel 4-aryl-3-methyl-4,5-dihydro-l//-pyrazolo[34-b]pyridin-6(7H)ones via the reaction of 5-amino-3-methyl-1H-pyrazole,Meldrum’s acid and various arylaldehydes using one-pot three-component approach is described.This rapid method produced the products in short reaction times(3-4 min) and excellent yields(87-95%).     

A convenient synthesis of novel 5-arylidene-2-imino-4-thiazolidinones using base supported ionic liquid-like phase (SILLP) as efficient green catalyst

A facile and convenient protocol was developed for the synthesis of 5-arylidene-2-imino-4-thiazolidinones using solid basic catalyst immobilized onto supported ionic liquid-like phase (SILLP) in high yields (80?C95%). The X-ray analysis of the representative compound established the Z configuration of the product at the chiral axis.     

Diastereoselective Ruthenium-Catalyzed Michael Addition of Indoles to Hormone Steroids: An Efficient Route to New Indole Derivatives

Diastereoselective conjugate 1,4-addition of indoles to α,β-unsaturated carbonyl compounds (hormone steroids) using Ru(III) as catalyst is reported. It was found that RuCl₃·nH₂O catalyzes the Michael addition of indoles to hormone steroids, providing new 3-alkylated derivatives in good to excellent yields.