Archive for the ‘Uncategorized’ Category

Sn-Beta catalysed conversion of hemicellulosic sugars

Scientists from Denmark and the USA report the conversions of various pentoses and hexoses into methyl lactate and related products by using a Sn-Beta catalyst.

Esben Taarning and colleagues show that this Lewis Acidic zeotype material can convert hemicellulosic sugars into methyl lactate, glycoaldehyde dimethylacetal and methyl vinylglycolate.  The fact that this catalyst is able to convert both hexoses and pentoses to methyl lactate opens up the possibility of employing it in reactions with crude sugar mixtures.  This has major advantages over microorganism-catalysed reactions of sugars, as many microorganisms will often only use specific sugars as substrates.

This article will be free to access until the 12th March 2012!  Click on the link below to find out more…

Sn-Beta catalysed conversion of hemicellulosic sugars, Martin S. Holm, Yomaira J. Pagán-Torres, Shunmugavel Saravanamurugan, Anders Riisager, James A. Dumesic and Esben Taarning, Green Chem., 2012, DOI: 10.1039/C2GC16202D

You may also be interested to read these articles by the same authors – free to access for 2 weeks!

Production of liquid hydrocarbon fuels by catalytic conversion of biomass-derived levulinic acid, Drew J. Braden, Carlos A. Henao, Jacob Heltzel, Christos C. Maravelias and James A. Dumesic, Green Chem., 2011, 13, 1755-1765

Dependency of the hydrogen bonding capacity of the solvent anion on the thermal stability of feruloyl esterases in ionic liquid systems, Birgitte Zeuner, Tim Ståhlberg, Olivier Nguyen van Buu, Andreas Jonas Kunov-Kruse, Anders Riisager and Anne S. Meyer, Green Chem., 2011, 13, 1550-1557

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Green Chemistry Issue 2 now online!

The latest issue of Green Chemistry is now available online.

The front cover of this issue features work by Rodrigo Teixeira from the University of Alabama in Huntsville, USA who reports the energy efficient extraction of fuel and chemical feedstocks from algae.  The deconstruction of algae cell walls and release of the cells contents was achieved by dissolution and hydrolysis of wet algae biomass in ionic liquids.  This process does not require acids, bases or any other catalysts, and can be completed in less than 50 mins (regardless of the algae species) at 100-140 °C and atmospheric pressure. 

Energy-efficient extraction of fuel and chemical feedstocks from algae, Rodrigo E. Teixeira, Green Chem., 2012, 14, 419-427

The inside front cover highlights work by Richard Daniellou, Daniel Plusquellec and colleagues from the National School of Chemistry of Rennes and the European University of Brittany, France, who report aqueous solutions of facial amphiphilic carbohydrates as a sustainable media for organocatalyzed direct aldol reactions.  Their system was applied to the direct aldol reaction of m-nitrobenzaldehyde with various cyclohexanones, and proceeded with high yields, shortened reaction times and improved diastereoselectivities. 

Aqueous solutions of facial amphiphilic carbohydrates as sustainable media for organocatalyzed direct aldol reactions, Ana Bellomo, Richard Daniellou and Daniel Plusquellec, Green Chem., 2012, 14, 281-284

Read these articles for free until the 14th March 2012!

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One-pot synthesis of heterocycles

Read about two of our latest hot articles on one-pot syntheses of heterocycles…

Yong Huang (Peking University, China) and Hong Shen (Merck Research Laboratories, New Jersey, USA) and colleagues report the synthesis of medicinally useful heterocycles such as pyridazinones and dihydropyrimidinones through a mild and highly efficient one-pot triple cascade procedure.  The cascade involves a Claisen-decarboxylation, an electrophilic reaction and subsequent heterocyclisation.  Indazoles and benzofurans could also be constructed through a double cascade reaction.  Click on the link below to find out more…

One-pot synthesis of useful heterocycles in medicinal chemistry using a cascade strategy, Guiyong Wu, Weiyu Yin, Hong C. Shen and Yong Huang, Green Chem., 2012, DOI: 10.1039/C2GC16457D

Li-Rong Wen, Ming Li and colleagues from Qingdao University of Science and Technology, China, present the efficient, solvent-free synthesis of imidazo[1,2-α]pyridine derivatives via a one-pot three-component reaction.  The reaction involves annualtion of heterocyclic ketene aminals and β-oxodithioesters with aldehydes using ET3N as the catalyst. The procedure is completed quickly with high regioselectivity and allows for easy purification.  Click on the link below to find out more…

Solvent-free and efficient synthesis of imidazo[1,2-a]pyridine derivatives via a one-pot three-component reaction, Li-Rong Wen, Zhao-Rui Li, Ming Li and Han Cao, Green Chem., 2012, DOI: 10.1039/C2GC16388H

These articles are free to access until the 2nd March 2012!  

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Development of recyclable catalysts

Catalysis is one of the most important areas of process and synthetic chemistry.  In view of the vast range of applications, there has been extensive research into making catalysts and catalytic reactions more economical and environmentally friendly.  One aspect of this is developing catalysts which can be recycled and reused over and over again with minimal effort.  This can be particularly important when considering the viability of a process for industrial development, as catalysts are often expensive and so need to be recovered wherever possible in order to keep down costs.

Green Chemistry provides an excellent forum for such work and below is a selection of the cutting edge research we have published in this area over the last couple of years.  These articles have been made free to access until the 27th February 2012, so make the most of this and take a look…

Why not keep up-to-date with the latest content in Green Chemistry by registering for our free table of contents alerts!

Heterogeneously catalysed Strecker-type reactions using supported Co(II) catalysts: microwave vs.conventional heating, Fatemeh Rajabi, Saghar Nourian, Sara Ghiassian, Alina M. Balu, Mohammad Reza Saidi, Juan Carlos Serrano-Ruiz and Rafael Luque, Green Chem., 2011, 13, 3282-3289

Recyclable copper catalysts based on imidazolium-tagged C2-symmetric bis(oxazoline) and their application in D–A reactions in ionic liquids, Zhi-Ming Zhou, Zhi-Huai Li, Xiao-Yan Hao, Xiao Dong, Xin Li, Li Dai, Ying-Qiang Liu, Jun Zhang, Hai-feng Huang, Xia Li and Jin-liang Wang, Green Chem., 2011, 13, 2963-2971

Amorphous carbon-silica composites bearing sulfonic acid as solid acid catalysts for the chemoselective protection of aldehydes as 1,1-diacetates and for N-, O– and S-acylations, Princy Gupta and Satya Paul, Green Chem., 2011, 13, 2365-2372

Recyclable mesoporous silica-supported chiral ruthenium-(NHC)NN-pincer catalysts for asymmetric reactions, Carolina del Pozo, Avelino Corma, Marta Iglesias and Félix Sánchez, Green Chem., 2011, 13, 2471-2481

Simple and recyclable ionic liquid based system for the selective decomposition of formic acid to hydrogen and carbon dioxide, M. E. M. Berger, D. Assenbaum, N. Taccardi, E. Spiecker and P. Wasserscheid, Green Chem., 2011, 13, 1411-1415

An efficient and heterogeneous recyclable palladium catalyst for chemoselective conjugate reduction of α,β-unsaturated carbonyls in aqueous medium, Dattatraya B. Bagal, Ziyauddin S. Qureshi, Kishor P. Dhake, Shoeb R. Khan and Bhalchandra M. Bhanage, Green Chem., 2011, 13, 1490-1494

Iron(III)-based ionic liquid-catalyzed regioselective benzylation of arenes and heteroarenes, Jian Gao, Jin-Quan Wang, Qing-Wen Song and Liang-Nian He, Green Chem., 2011, 13, 1182-1186

Pd immobilized on amine-functionalized magnetite nanoparticles: a novel and highly active catalyst for hydrogenation and Heck reactions, Fengwei Zhang, Jun Jin, Xing Zhong, Shuwen Li, Jianrui Niu, Rong Li and Jiantai Ma, Green Chem., 2011, 13, 1238-1243

Catalytic oxidative desulfurization with a hexatungstate/aqueous H2O2/ionic liquid emulsion system, Yuxiao Ding, Wenshuai Zhu, Huaming Li, Wei Jiang, Ming Zhang, Yuqing Duan and Yonghui Chang, Green Chem., 2011, 13, 1210-1216

Supported ionic liquid silica nanoparticles (SILnPs) as an efficient and recyclable heterogeneous catalyst for the dehydration of fructose to 5-hydroxymethylfurfural, Kalpesh B. Sidhpuria, Ana L. Daniel-da-Silva, Tito Trindade and João A. P. Coutinho, Green Chem., 2011, 13, 340-349

A silica gel supported dual acidic ionic liquid: an efficient and recyclable heterogeneous catalyst for the one-pot synthesis of amidoalkyl naphthols, Qiang Zhang, Jun Luo and Yunyang Wei, Green Chem., 2010, 12, 2246-2254

Highly recyclable, imidazolium derived ionic liquids of low antimicrobial and antifungal toxicity: A new strategy for acid catalysis, Lauren Myles, Rohitkumar Gore, Marcel Špulák, Nicholas Gathergood and Stephen J. Connon, Green Chem., 2010, 12, 1157-1162

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Systematic optimization of a biocatalytic two-liquid phase oxyfunctionalization process guided by ecological and economic assessment

Scientists from Germany have optimized and assessed the ecological performance of a whole-cell two-liquid phase biocatalytic epoxidation of styrene.

Bruno Bühler and colleagues from the Technical University of Dortmund and Saarland University, Germany, considered how the ecological aspects of this reaction could be improved.  Currently, the ecological performance is hampered by the organic carrier solvent employed (bis(2-ethylhexyl)phthalate) which is toxic to humans and is produced from non-renewable resources.  Instead ethyl oleate (a biodiesel constituent) was tested and shown to be an environmentally attractive and cost-competitive solvent.

The authors also replaced the carbon/energy source glucose with glycerol as the latter is a waste product from the biodiesel and soap industries and thus cheap and abundant.  However, the use of glycerol was found to reduce the overall ecological and economic performance of the process.  The work presented here by Bühler and co-workers illustrates the capability of these assessments to identify critical process parameters and to enable systematic development towards industrial implementation.

This article is free to access until the 24th February 2012!  Click on this link below to find out more…

Systematic optimization of a biocatalytic two-liquid phase oxyfunctionalization process guided by ecological and economic assessment, Daniel Kuhn, Mattijs K. Julsing, Elmar Heinzle and Bruno Bühler, Green Chem., 2012, DOI: 10.1039/C2GC15985F

You may find this article of interest too – also free to access until the 24th February 2012, so why not take a look…

Intensification and economic and ecological assessment of a biocatalytic oxyfunctionalization process, Daniel Kuhn, Muhammad Abdul Kholiq, Elmar Heinzle, Bruno Bühler and Andreas Schmid, Green Chem., 2010, 12, 815-827

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Tailor-made biopolymers from leather waste valorisation

Scientists from Spain report tailor-made collagen biopolymers from tanning waste with diverse shapes such as fibers, films and sponges. 

Mercedes Catalina (Advanced Chemistry Institute of Catalunya), Rafael Luque (University of Cordoba) and colleagues valorised tanning waste from leather processing to give biopolymers which could be easily modified using various methodologies with the aim of generating waste-derived renewable biopolymers.  For example, introducing cross-linking agents on the  matrix network of the biopolymer provided a material with improved properties.  The authors envisage these materials could have promising in fields such as cosmetics and medicines.

This article is free to access until the 18th February 2012! Click on the link below to find out more…

Tailor-made biopolymers from leather waste valorisation, Mercedes Catalina, Jaume Cot, Alina Mariana Balu, Juan Carlos Serrano-Ruiz and Rafael Luque, Green Chem., 2012, DOI: 10.1039/C2GC16330F

You may find this review article of interest too which is also free to access.  Why not take a look…

Waste materials – catalytic opportunities: an overview of the application of large scale waste materials as resources for catalytic applications, M. Balakrishnan, V. S. Batra, J. S. J. Hargreaves and I. D. Pulford, Green Chem., 2011, 13, 16-24

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Linseed and soybean oil-based polyurethanes prepared via the non-isocyanate route and catalytic carbon dioxide conversion

Soy- and linseed oil-based polyurethanes were synthesized by curing carbonated soybean and linseed oils with different diamines. 

Moritz Bähr and Rolf Mülhaupt from the Freiburg Materials Research Center (FMF) and Department of
Macromolecular Chemistry, Germany, have developed a non-isocyante route to soy- and linseed oil-based polyurethanes.  The route involved conversion of the epoxidised seed oils with carbon dioxide to form cyclic carbonates catalysed by tetra-butylammonium bromide and silica supported 4-pyrrolidinopyridium iodide.  The catalysts could be easily recovered without needing traditional solvent extraction.  The resulting carbonates were then cured with various amines to give the polyurethanes.

As well as avoiding the use of toxic chemicals, this route also led to some polkyurethanes with increased glass transition temperatures and improved stiffness.  To find out more, just click on the article link below.  This article is currently free to access until the 15th February 2012!

Linseed and soybean oil-based polyurethanes prepared viathe non-isocyanate route and catalytic carbon dioxide conversion, Moritz Bähr and Rolf Mülhaupt, Green Chem., 2012, DOI: 10.1039/C2GC16230J

You may also find these articles of interest – free to access until the 15th February 2012 too!  So why not take a look…

Biorenewable polyethylene terephthalate mimics derived from lignin and acetic acid, Laurent Mialon, Alexander G. Pemba and Stephen A. Miller, Green Chem., 2010, 12, 1704-1706

Vegetable oil-based polymeric materials: synthesis, properties, and applications, Ying Xia and Richard C. Larock, Green Chem., 2010, 12, 1893-1909

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Green Chemistry article in C&EN

A recently published Green Chemistry aricle by David Cole-Hamilton (University of St. Andrews, UK), Stefan Mecking (University of Konstanz, Germany) and colleagues has just been featured in the latest issue of Chemistry & Engineering News (C&EN). 

The paper reports the synthesis of the diester dimethyl 1,19-nonadecanedioate from the palladium catalysed methoxycarbonylation of various commerial oils, including olive and sunflower oils.  The resulting product can then be easily converted to the diol and diacid, and all three chemicals can serve as useful polymer precursors. 

This article is now free to access until the 15th February 2012!  Click the link below to find out more…

Polymer precursors from catalytic reactions of natural oils, Marc R. L. Furst, Ronan Le Goff, Dorothee Quinzler, Stefan Mecking, Catherine H. Botting and David J. Cole-Hamilton, Green Chem., 2012, DOI: 10.1039/C1GC16094J

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Hot articles in ‘green’ organic synthesis

Read about our latest hot articles in green organic synthesis…

Martin Kluge and colleagues from the International Graduate School of Zittau and Lausitz University of Applied Sciences, Germany, report the stereoselective benzylic hydroxylation of alkybenzenes and epoxidation of styrene derivatives catalysed by the peroxygenase from the fungus Agrocybe aegerita.  This method avoids the use of transition metal catalysts and harsh reactions conditions present in other methods.  By using fed-batch devices and varying feeding strategies for the substrates, the Kluge and co-workers developed a suitable approach to optimize peroxygenase catalysis.

Antonio Braga and colleagues from the Federal University of Santa Catarina and the Federal University of Santa Maria, Brazil, report the synthesis of selenol esters from diorganyl diselenides and acyl cholrides under solvent-free conditions and microwave irradiation.  They describe an efficient, fast and eco-friendly method for the synthesis of selenol esters, which provided good to excellent yields of the products after just two minutes of microwave irradiation. 

Read these articles for free until 11th February 2012!

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Green Chemistry Issue 1, 2012 now online!

Issue 1 2012 of Green Chemistry is now online!

The front cover of the issue highlights work by Graham Hutchings and colleagues from Cardiff University, UK, who prepared several Au-Pd exchanged supported Cs-heteropolyacid catalysts and applied them to the direct synthesis of hydrogen peroxide from H2 and O2 in water under ambient conditions

The inside front cover features work by George Huber and co-workers from the University of Massachusetts-Amherst, USA and Southeast University, China, who report the catalytic fast pyrolysis of wood and alcohol mistures in a fluidized bed reactor.  By looking at the various reaction parameters, the authors demonstrate that catalytic fast pyrolysis can selectively produce a mixture of compounds and that the overall yield is a function of the hydrigen to carbon effective ratio. 

All articles in this issue are free to access.

Don’t forget to keep up-to-date with our latest hot articles and reviews!

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