Month: October 2013

Green N-Methylation of Electron Deficient Pyrroles with Dimethylcarbonate

The N-methylation of electron-deficient pyrroles was affected using dimethyl carbonate in the presence of DMF and catalytic DABCO. This alkylation methodology has proven useful for the alkylation of a variety of pyrroles in 72−98% yields and is considered to be greenchemistry relative to the more common use of methyl halides or dimethyl sulfate. Michael L. Laurila , Nicholas A.… Continue reading Green N-Methylation of Electron Deficient Pyrroles with Dimethylcarbonate

Article On Alternative Solvents:  Shades of Green

The use of alternative reaction solvents is reviewed in terms of life cycle. Supercritical CO2, ionic liquids, fluorous solvents, water, and renewable organics are compared on the basis of their solvency, ease of use, reusability, health and safety, environmental impact, and economic cost. James H. Clark * and Stewart J. Tavener Green Chemistry Centre, Department of Chemistry, University… Continue reading Article On Alternative Solvents:  Shades of Green

GAP chemistry for pyrrolyl coumarin derivatives: a highly efficient one-pot synthesis under catalyst-free conditions

Green Chem., 2013, Advance Article DOI: 10.1039/C3GC41799A, Communication Huiyan Wang, Xuecheng Liu, Xian Feng, Zhibin Huang, Daqing Shi This synthesis was confirmed to follow the GAP chemistry process, which can avoid traditional chromatography and recrystallization purification methods. GAP chemistry for pyrrolyl coumarin derivatives: a highly efficient one-pot synthesis under catalyst-free conditions http://pubs.rsc.org/en/Content/ArticleLanding/2013/GC/C3GC41799A?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract Huiyan Wang,ab   Xuecheng Liu,a   Xian… Continue reading GAP chemistry for pyrrolyl coumarin derivatives: a highly efficient one-pot synthesis under catalyst-free conditions

Lewis acid-surfactant-combined catalyzed synthesis of 4-aminocyclopentenones from glycals in water

Green Chem., 2013, 15,3180-3183 DOI: 10.1039/C3GC41032C, Communication Siming Wang, Ronny William, Kim Kui Georgina Estelle Seah, Xue-Wei Liu Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 Water makes the difference: an example of the Lewis acid-surfactant-combined catalyzed synthesis of biologically significant 4-aminocyclopentenones was developed.… Continue reading Lewis acid-surfactant-combined catalyzed synthesis of 4-aminocyclopentenones from glycals in water

RABEPRAZOLE

Pariprazole sodium;Rabeprazole sodium;LY-307640;E-3810;Aciphex;Pariet Rabeprazole /ˌræ.ˈbɛp.ræ.zɔːl/ is an antiulcer drug in the class of proton pump inhibitors. It was developed by Eisai Co. and is marketed by Janssen-Cilag as the sodium salt under the brand names AcipHex (/ˈæsɨfɛks/, referring to pH) in the US, Pariet in Europe, Brazil, Canada, Japan, Russia and Australia, Acigard, Cyra, Rabium, Esoon,Orporo, Parit, Rabemac, Rabiloz, Razo, Rabifast, Rablet and Rabsiv in India, and Zechin in… Continue reading RABEPRAZOLE

Axial-to-central chirality transfer in cyclization processes

Axial-to-central chirality transfer in cyclization processes Substrates, bearing axial chirality, can cyclize intra- or inter-molecularly with concomitant transfer of axial-to-central chirality to produce at least one stereocenter. In order to satisfy a strict definition of axial-to-central chirality transfer, the initial axial chirality must be lost during the cyclization process. Highly functionalized enantiopure carbocycles and heterocycles… Continue reading Axial-to-central chirality transfer in cyclization processes

An efficient palladium catalyst on bentonite for Suzuki-Miyaura reaction at room temperature

An efficient palladium catalyst on bentonite for Suzuki-Miyaura reaction at room temperature Green Chem., 2013, Advance Article DOI: 10.1039/C3GC41469H, Paper Guodong Ding, Weitao Wang, Tao Jiang, Buxing Han The Pd/bentonite catalyst prepared by a simple impregnation method in water is very active and stable for the Suzuki-Miyaura reaction. http://pubs.rsc.org/en/Content/ArticleLanding/2013/GC/C3GC41469H?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract Clays, which are nontoxic, abundant, and… Continue reading An efficient palladium catalyst on bentonite for Suzuki-Miyaura reaction at room temperature

Seeding removes barrier to curious cocrystal

Once the heteronuclear seeds had been used in the lab, the cocrystal formed regardless of whether or not the seeds were used The caffeine•benzoic acid cocrystal that has eluded scientists for 60 years has finally been crystallised Cocrystals are crystalline materials composed of two or more molecules held together within the same crystal lattice. Cocrystallisation… Continue reading Seeding removes barrier to curious cocrystal

Chemical conversion of biomass-derived hexose sugars to levulinic acid over sulfonic acid-functionalized graphene oxide catalysts

Green Chem., 2013, 15,2935-2943 DOI: 10.1039/C3GC40353J, Paper Pravin P. Upare, Ji-Woong Yoon, Mi Yeon Kim, Hyo-Yoon Kang, Dong Won Hwang, Young Kyu Hwang, Harold H. Kung, Jong-San Chang Sulfonated graphene oxide (GO-SO3H) catalyst selectively decomposes glucose to levulinic acid (LA) with excellent yield (around 78%). Chemical conversion of biomass-derived hexose sugars to levulinic acid over sulfonic… Continue reading Chemical conversion of biomass-derived hexose sugars to levulinic acid over sulfonic acid-functionalized graphene oxide catalysts