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An efficient, regioselective, onepot and twostep synthesis of βhydroxy 1,4disubstituted 1,2,3triazoles from a wide range of nonactivated terminal alkynes and epoxides and sodium azide by way of a threecomponent click reactionusing a catalytic amount of mesotetrakisochlorophenylporphyrinatocopperII 5mol% in excellent isolated yields is described. The reactions were performed in water as a greensolvent at ambient temperature without any additives. By performing two reaction steps in one pot and purifying only at the final step, this procedure excludes any interim purification of in situgenerated organic azide intermediates, which significantly improves the overall yield and reduces the reaction time. To benefit from the recovery and reuse of the catalyst, a new heterogeneous catalyst was prepared by simple and successful impregnation of the catalyst onto activated multiwalled carbon nanotubes AMWCNT. The heterogeneous catalyst was characterized by powder Xray diffraction XRD, transmission electron microscopy TEM, scanning electron microscopy SEM, atomic forced microscopy AFM, and thermogravimetric TG analysis to estimate the amount of nitrogen adsorption, and Raman and FTIR spectroscopy. Leaching experiments after ten successive cycles showed that the catalyst is most strongly anchored to the AMWCNT support. Mechanistically, porphyrinatocopper catalyzes each step of the reaction in different ways as a bifunctional catalyst including epoxide ring opening by azide delivery to epoxide, forming in situgenerated 2azido alcohols followed by activation of the CC triple bond of the starting terminal alkynes by forming a porphyrinatocopperacetylide intermediate and thereby promoting the 32cycloaddition reaction as the key step to form the triazole framework.

An efficient and highly selective synthesis of 2arylbenzimidazoles by condensation of a wide range of aryl aldehydes bearing electrondonating or withdrawing substituents and phenylenediamines in a single pot using a catalytic amount of mesotetrakisochlorophenylporphyrinatoironIII chloride 5 mol in excellent isolated yields is described. The reactions were performed in the presence of atmospheric air as a “green” oxidant at ambient temperature in ethanol without any additives. To benefit from the recovery and reuse of the catalyst, a new ironIII porphyrin–silica heterogeneous catalyst was prepared by simple and successful impregnation of mesotetrakisochlorophenylporphyrinatoironIII chloride onto activated commercial chromatographic silica gel. The silica was modified by treatment with HCl solution followed by NaOH solution, giving rise to the transformation of –O– strained siloxane atoms and silanol–OH groups into terminal negatively charged silanol–O–groups. The heterogeneous catalyst was characterized by powdered Xray diffraction XRD, scanning electronic microscopy SEM, atomic force microscopy AFM, thermogravimetry TG to analyse for nitrogen adsorption, and Raman and FTIR spectroscopy. Leaching experiments showed that the catalyst is most strongly anchored to the activated support after 10 cycles. ToClPPFeIII–SiO2was successfully used for all runs performed by the homogeneous catalyst and exhibited high isolated yields, selectivity, reusability, and the potential for largescale synthesis. Mechanistically, the highvalent oxidoironIV–porphyrin could be the key intermediate in this efficient and highly selective synthesis of benzimidazole derivatives. © WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.