Journal of Chemical Reactivity and Synthesis
Volume:1 Issue: 4, Autumn 2011

A novel magnetically immobilized polyethyleneimine (PEI) fabricated by covalently anchoring on MCM-41 (MCM-41@PEI) was prepared. The synthesized catalyst was characterized by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The immobilized PEI was shown to be an efficient heterogeneous catalyst for the synthesis of spiro-oxindole and benzopyranes derivatives via multi-component reaction (MCR), in ethylene glycol as a green solvent. No leaching problem was observed after several runs, while the catalyst can be recovered and reused without loss of reactivity under the described reaction conditions.

Imidazo[2,1-b]thiazoles are obtaind in excellent yields from the addition reaction between thiohydantoin and ethylbromopyruvate.  These imidazo[2,1-b]thiazoles in the presence of p-TSA in boiling toluene refluxed for 2.5 hours led to imidazo[2,1-b]thiazole-3-carboxylates in elimination reactions

Novel imidazo[2,1-b]thiazoles were synthesized in good yield via a mild reaction of thiophenytoin and diethyl oxalatein the presence of 10% mol p-TSA.

In this study, a one-pot and efficient method is reported for the synthesis of symmetrical disulfides from alkyl halides in the present of sulfur and 1-butyl-3-methylimidazolium hydroxide as a basic reagent and phase transfer catalyst. The reaction proceeded very fast and afforded the desired products in moderate to excellent isolated yields.

7-hydroxy coumarin undergoes neutral conditions with alkyl propiolates in the presence of triphenylphosphine, and bysubstituation the corresponding aryl vinyl ethers was obtained in good yields

A natural and efficient method has been developed for the synthesis of quinoline derivatives in good-to-high yields, from various aryl aldehydes, amines and phenyl acethylene, using marine sponge/I2 as a green catalyst

The  inhibition effects seed and peel of melon on diphenolase activity of mashroom tyrosinase were investigated. The IC50 values and Ki values of seed and peel of melon were evaluated. increased the Km value and decreased the Vm value so it show mixed type inhibition on mushroom tyrosinase when L-DOPA was used as a substrate.

An efficient synthesis of vinylphosphonates is described. This involves the reaction of alkyl cyanoformates and dialkyl acetylendicarboxylates in the presence of trialkyl phosphites. The 1H, 13C NMR, and 31P NMR spectra of vinylphosphonates having different substitution are consistent with the presence of two geometrical isomers.