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Noroozi Pesyan N.,Urmia University | Gharib A.,Islamic Azad University at Mashhad | Gharib A.,Agricultural Researches and Services Center | Behroozi M.,Urmia University | Shokr A.,Urmia University
Arabian Journal of Chemistry | Year: 2013

Reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione (Meldrum's acid) with various aldehydes in the presence of cyanogen bromide and triethylamine leads to the selective and efficient formation of full-substituted cyclopropanes at room temperature. The products were obtained in good to excellent yields. Structure elucidation is carried out by 1H, 13C NMR, FT-IR spectroscopy and mass analysis techniques. A possible mechanism for the formation is discussed. © 2013. Source


Gharib A.,Islamic Azad University at Mashhad | Gharib A.,Agricultural Researches and Services Center | Jahangir M.,Islamic Azad University at Mashhad | Scheeren J.,Radboud University Nijmegen
Polish Journal of Chemical Technology | Year: 2011

The Preyssler, Wells-Dowson and Keggin heteropolyacids are efficient and eco-friendly solid acid catalysts for the acylation of electron-rich aromatic compounds with acid anhydrides. The performance of different forms of heteropolyacids was compared. In all the cases, the best results were obtained using the Preyssler heteropolyacid as the catalyst. In the presence of 25 mol% (with respect to H+ equivalency) Preyssler catalyst, highly para-selective acetylation of anisole occurs using two equivalents of acetic anhydride, in 15 min at room temperature. The isolated yield of the p-methoxyacetophenone product is 98%. Source


Gharib A.,Islamic Azad University at Mashhad | Gharib A.,Agricultural Researches and Services Center | Jahangir M.,Islamic Azad University at Mashhad | Scheeren J.H.W.,Radboud University Nijmegen
Synthetic Communications | Year: 2013

The catalytic performance of Preyssler, H 14[NaP5W 30O 110]: Wells-Dawson, H6[P 2W 18O 62]; and Keggin, H3[PW 12O 40] and H 4[PMo 11VO 40], heteropolyacids as pure compounds have been studied in the synthesis of pyrazoles and diazepines in the condensation of hydrazines, hydrazides, and diamines with various 1,3-diketones. In all cases the best yields were obtained using H 14[NaP 5W 30O 110]. Copyright © Taylor and Francis Group, LLC. Source


Noroozi Pesyan N.,Urmia University | Shokr A.,Urmia University | Gharib A.,Islamic Azad University at Mashhad | Gharib A.,Agricultural Researches and Services Center | And 2 more authors.
Journal of the Chinese Chemical Society | Year: 2015

Crossed one-pot reaction of mixed cyclic β-dicarbonyl with various aldehydes in the presence of cyano gen bromide and triethylamine leads to the selective and efficient formation of crossed new unsymmetri cal spiro dihydrofurans at room temperature. The products were obtained in good to excellent yields. Structure elucidation was carried out by 1H NMR, 13C NMR, FT-IR spectroscopy, Mass analyses and X-ray crystallography technique. A proposed mechanism was discussed for the formation of products. © 2015 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany. Source


Gharib A.,Islamic Azad University at Mashhad | Gharib A.,Agricultural Researches and Services Center | Jahangir M.,Islamic Azad University at Mashhad | Scheeren J.,Radboud University Nijmegen
Polish Journal of Chemical Technology | Year: 2011

A catalytic synthesis of calix[4]pyrroles and N-confused calix[4]pyrroles by reaction of dialkyl or cycloalkyl ketones with pyrrole was performed using Preyssler, sodium30-tungsto pentaphosphate, [NaP5W30O 110]14- and Wells-Dawson heteropolyacids as acidic catalysts. The process occurred under mild, eco-friendly and environmental friendly conditions and as a reusable, green catalyst at room temperature for 6 hours. The results showed that the yield for this synthesis is excellent with the use of Preyssler and Wells-Dawson type tungstophosphoric heteropolyacid, H6[P2W18O62], catalysts. The synthesis reaction of calix[4]pyrroles and N-confused calix[4]pyrroles was developed using different solvents and the best yields were obtained in chloroform. Source

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