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Ionic liquid pretreatment of ligonocellulosic biomass with ionic liquid-water mixtures

Ionic liquids containing methyl sulfate, hydrogen sulfate and methanesulfonate anions were used to pretreat lignocellulose in the presence of water.

Ionic liquids (ILs) are salts which are liquid at room or slightly elevated temperatures, and the majority have negligible vapour pressures.  One of the applications of ILs is in the pretreatment and processing of biomass (e.g. cellulose and lignocellulose).  However, the presence of water in these processes reduces the solubility of the biomass in the ILs and therefore the effectiveness of the pretreatment.  ILs currently have to be dried before use which requires heat and vacuum, but as biomass contains significant quantities of water, it would be far more beneficial to have an IL pretreatment process that tolerates moisture.

In this work, Welton and co-workers from Imperial College London have used IL and water mixtures of 1-butyl-3-methylimidazolium methyl sulfate and 1-butyl-3-methylimidazolium hydrogen sulfate to pretreat ground lignocellulosic biomass.  These ILs were shown to work effectively in the presence of significant quantities of water thereby eliminating the need for anhydrous conditions during the process.

To find out more, please click on the link below:

Ionic liquid pretreatment of lignocellulosic biomass with ionic liquid–water mixtures, Agnieszka Brandt, Michael J. Ray, Trang Q. To, David J. Leak, Richard J. Murphy and Tom Welton, Green Chem., 2011, DOI: 10.1039/C1GC15374A

This article is free to access until the 21st September 2011

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Ecofriendly hydrogen production from hydrogen sulfide using a nanostructured photocatalyst driven by solar light

The photocatalyst ZnIn4S4was synthesized hydrothermally and applied to the conversion of hydrogen sulfide to hydrogen under solar light.

Scientists from India have demonstrated that a zinc nanostructured photocatalyst could be used to decompose hydrogen sulfide (H2S) into hydrogen (H2).  H2S is commonly converted into water and sulfur using the Claus process. However this process is not considered to be environmentally viable due to its high cost and the fact that it usually creates further environmental problems.  This has switched interest into converting H2S into H2 in order to try and avoid these issues.

Kale and colleagues report here the controlled synthesis of ZnIn4S4by a hydrothermal method and its application to H2S conversion to H2 using solar energy.  The H2 evolution rate obtained is much higher compared to earlier reported photocatalysts.

To read more, just click on the link below.  This article is free to access until the 21st September 2011!

Ecofriendly hydrogen production from abundant hydrogen sulfide using solar light-driven hierarchical nanostructured ZnIn2S4photocatalyst, Nilima S. Chaudhari, Ashwini P. Bhirud, Ravindra S. Sonawane, Latesh K. Nikam, Sambhaji S. Warule, Vilas H. Rane and Bharat B. Kale, Green Chem., 2011, DOI: 10.1039/C1GC15515F

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Dimethyl phosphorothioate and phosphoroselenoate ionic liquids as solvent media for cellulosic materials

A series of novel ionic liquids have been synthesized and applied to the dissolution of cellulose materials without causing considerable degradation of the polymer.

Hummel and co-workers from Finland and Austria have prepared by a facile route, a series of novel ionic liquids (ILs) which comprise of two asymmetric anions – dimethyl phosphorothioate and dimethyl phosphoroselenoate – and several imidazolium and non-imidazolium cations.  The principle of the work was to design an ionic liquid with reduced viscosity, while preserving its ability to dissolve lignocellulosic material, by altering the anion.

Hummel tested these new ionic liquids in the dissolution of cellulose, and the dimethyl phosphorothioate ionic liquids were able to dissolve cellulose with a high degree of polymerization but without extensive degradation.

To read more, please click on the link below.  This article is free to access until the 14th September 2011!

Dimethyl phosphorothioate and phosphoroselenoate ionic liquids as solvent media for cellulosic materials, Michael Hummel, Carmen Froschauer, Gerhard Laus, Thomas Röder, Holger Kopacka, Lauri K. J. Hauru, Hedda K. Weber, Herbert Sixta and Herwig Schottenberger, Green Chem., 2011, DOI: 10.1039/C1GC15407A

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Eco-friendly synthesis of β-nitro ketones

A variety of β-nitro ketones have been synthesised at room temperature using a supported nitrite.

Scientists from Italy have developed a more eco-friendly route to synthesize β-nitro ketones.  Nitroalkanes are an important class of organic substrates as the nitro group can be converted into many other functionalities, which makes them key starting materials for many fine chemicals.  Currently, the main method to make these compounds is by a Miyakoshi procedure – however, the method is limited to simple α,β-unsaturated ketone starting materials, gives only moderate yields and requires the presence of volatile organic solvents.

However, in this work, β-nitro ketones could be synthesized from a variety of α,β-unsaturated ketones using a solid supported nitrite, acetic acid and cyclopentyl methyl ether (CPME), an emerging ‘green solvent’.  This method works well with complex starting materials and it is able to preserve other functionalities, thereby minimizing work-up procedures (simple filtration and evapouration of the acetic acid and solvent) and decreasing the E-factor.

To read more, please click the link below:

Eco-friendly synthesis of β-nitro ketones from conjugated enones: an important improvement of the Miyakoshi procedure, Serena Gabrielli, Alessandro Palmieri, Alvise Perosa, Maurizio Selva and Roberto Ballini,  Green Chem., 2011, 13, 2026-2028, DOI: 10.1039/C1GC15616K

This article is free to access until 14th September!

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Green ruthenium-catalysed reactions

Recyclable mesoporous silica-supported chiral ruthenium-(NHC)NN-pincer catalysts for asymmetric reactions.  Scientists from Spain have reported two new stable chiral Ru-pincer complexes with a pendant silyloxy group, which were grafted onto a mesoporous silica (MCM-41).  These supported complexes were shown to be highly active and recyclable catalysts for the asymmetric hydrogenation of alkenes and the cyclopropanation of styrenes.  These catalysts avoid the draw-backs associated with homogeneous catalysts such as high catalyst loadings and difficulties in catalyst recovery.  The supported catalysts reported here showed no deactivation after repeated recycling. (Green Chem., 2011, DOI 10.1039/c1gc15412e)

C-H bond functionalisation with [RuH(codyl)2]BF4 catalyst precursor.  Scientists from the CNRS-University of Rennes, France have employed a ruthenium catalyst, assisted by a coordinating base, for the direct diarylation of arenes with (hetero)arylhalides.  This reaction under these conditions is milder that the classical organometallic cross-coupling reactions.  The coordinating ligand/base has an important role by promoting the initial cleavage of the C-H bond.  The efficiency of the system strongly depends on the nature of both the assisting ligand/base and the (hetero)aryl halides. (Green Chem., 2011, DOI: 10.1039/c1gc15642j)

These articles are free to access until September 9th!

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Controlled lactide polymerisation in supercritical carbon dioxide with organo-catalyst

Researchers from Australia and the UK have developed a truly ‘green’ process for the synthesis of polylactic acid in the absence of toxic solvents and catalysts.

The team led by Idriss Blakely (The University of Queensland, Australia) and Steven Howdle (University of Nottingham, UK) have developed an approach where polylactide can be synthesised in a controlled manner in supercritical CO2 using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as an organo-catalyst.  This new method, unlike others before it, does not require the use of organic solvents or metal catalysts, and is conducted at much lower temperatures than for bulk polymerisation of lactic acid.

To read more, click the link below! FREE until 27 July.

Controlled polymerisation of lactide using an organo-catalyst in supercritical carbon dioxide, Idriss Blakey, Anguang Yu, Steven M. Howdle, Andrew K. Whittaker and Kristofer J. Thurecht, Green Chem., 2011, DOI: 10.1039/C1GC15344G

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Direct conversion of polyamides to ω-hydroxyalkanoic acid derivatives by using supercritical MeOH, Akio Kamimura, Kouji Kaiso, Shuzo Suzuki, Yusuke Oishi, Yuki Ohara, Tsunemi Sugimoto, Kohichi Kashiwagi and Makoto Yoshimoto, Green Chem., 2011, DOI: 10.1039/C1GC15172J

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Top ten most accessed articles in December

This month sees the following articles in Green Chemistry that are in the top ten most accessed:-

Glycerol dehydration to acrolein in the context of new uses of glycerol 
Benjamin Katryniok, Sébastien Paul, Virginie Bellière-Baca, Patrick Rey and Franck Dumeignil 
Green Chem., 2010, 12, 2079-2098, DOI: 10.1039/C0GC00307G, Critical Review 

Synthesis of sugar alcohols by hydrolytic hydrogenation of cellulose over supported metal catalysts 
Hirokazu Kobayashi, Yukiko Ito, Tasuku Komanoya, Yuto Hosaka, Paresh L. Dhepe, Koji Kasai, Kenji Hara and Atsushi Fukuoka 
Green Chem., 2011, Advance Article, DOI: 10.1039/C0GC00666A, Paper 

Synergy of boric acid and added salts in the catalytic dehydration of hexoses to 5-hydroxymethylfurfural in water 
Thomas S. Hansen, Jerrik Mielby and Anders Riisager 
Green Chem., 2011, 13, 109-114, DOI: 10.1039/C0GC00355G, Paper 

Synthesis of thermoplastic starch mixed esters catalyzed by the in situ generation of imidazolium salts 
André Lehmann, Bert Volkert, Mehdi Hassan-Nejad, Tonino Greco and Hans-Peter Fink 
Green Chem., 2010, 12, 2164-2171, DOI: 10.1039/C0GC00366B, Paper 

ß-cyclodextrin catalysed synthesis of tryptanthrin in water 
Atul Kumar, Vishwa Deepak Tripathi and Promod Kumar 
Green Chem., 2011, 13, 51-54, DOI: 10.1039/C0GC00523A, Communication 

Eco-friendly liquid chromatographic separations based on the use of cyclodextrins as mobile phase additives 
Víctor González-Ruiz, Andrés G. León, Ana I. Olives, M. Antonia Martín and J. Carlos Menéndez 
Green Chem., 2011, 13, 115-126, DOI: 10.1039/C0GC00456A, Paper 

An efficient copper-catalysed aerobic oxybromination of arenes in water 
Jian Wang, Wei Wang and Jing-Hua Li 
Green Chem., 2010, 12, 2124-2126, DOI: 10.1039/C0GC00328J, Communication 

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, DOI: 10.1039/C0GC00685H, Tutorial Review 

A green protocol for palladium-catalysed Suzuki-Miyaura cross-coupling 
Alexander N. Marziale, Dominik Jantke, Stefan H. Faul, Thomas Reiner, Eberhardt Herdtweck and Jörg Eppinger 
Green Chem., 2011, 13, 169-177, DOI: 10.1039/C0GC00522C, Paper 

Selective hydrogenolysis of biomass-derived xylitol to ethylene glycol and propylene glycol on supported Ru catalysts 
Jiying Sun and Haichao Liu 
Green Chem., 2011, 13, 135-142, DOI: 10.1039/C0GC00571A, Paper 

Why not take a look at the articles today and blog your thoughts and comments below.

Fancy submitting an article to Green Chemistry? Then why not submit to us today or alternatively email us your suggestions.

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Nominations for the 2011 RSC Prizes and Awards are now open

The RSC currently presents around 60 prestigious Prizes and Awards annually to scientists in all the main chemical science disciplines allowing for the greatest range of scientists to be recognised for their work; individuals, teams and organisations working across the globe.

There are nine categories of awards including specific categories for Industry and Education so whether you work in business, industry, research or education recognition is open to everyone.

Our Prizes and Awards represent the dedication and outstanding achievements in the chemicals sciences and are a platform to showcase inspiring science to gain the recognition deserved.

Do you know someone who has made a significant contribution to advancing the chemical sciences?

View our full list of Prizes and Awards and use the online system to nominate yourself or colleagues.

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Inviting submissions from the Asia Pacific Conference on Ionic Liquids and Green Processes

We invite you to contribute to a web-themed issue on ionic liquid and green processes.

Contributors to the 2nd Asia Pacific Conference on Ionic Liquids and Green Processes (APCIL-2) are invited to submit their work to Green Chemistry and those that are accepted for publication will be collated in a Green Chemistry SCI-indexed web themed issue dedicated to the conference.

We welcome the submission of primary research full papers, communications, critical reviews or perspectives within the scope of the Journal. If you would like to submit a review article based on the work presented at the conference, please do contact us to discuss this further.

The deadline for the submission of articles for the themed issue is 30th of September2010.

All articles will be peer-reviewed and will be published as Advance Articles online as soon as they are ready. All manuscripts will have a conference footnote added upon publication and all accepted papers will be collated as a web-themed issue dedicated to the conference. 

If you have any questions regarding the submission process please contact us: green-rsc@rsc.org.

Manuscripts can be submitted online: http://mc.manuscriptcentral.com/gc .

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Top ten most accessed articles in July

This month sees the following articles in Green Chemistry that are in the top ten most accessed:-

Glycerol as a sustainable solvent for green chemistry 
Yanlong Gu and François Jérôme 
Green Chem., 2010, 12, 1127-1138, DOI: 10.1039/C001628D , Critical Review 

Development of safe and scalable continuous-flow methods for palladium-catalyzed aerobic oxidation reactions 
Xuan Ye, Martin D. Johnson, Tianning Diao, Matthew H. Yates and Shannon S. Stahl 
Green Chem., 2010, 12, 1180-1186, DOI: 10.1039/C0GC00106F , Paper 

Catalytic production of hydrogen from glucose and other carbohydrates under exceptionally mild reaction conditions 
N. Taccardi, D. Assenbaum, M. E. M. Berger, A. Bösmann, F. Enzenberger, R. Wölfel, S. Neuendorf, Volker Goeke, N. Schödel, H. -J. Maass, H. Kistenmacher and P. Wasserscheid 
Green Chem., 2010, 12, 1150-1156, DOI: 10.1039/C002910F , Communication 

A two-step approach for the catalytic conversion of glucose to 2,5-dimethylfuran in ionic liquids 
Mandan Chidambaram and Alexis T. Bell 
Green Chem., 2010, 12, 1253-1262, DOI: 10.1039/C004343E , Paper 

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, DOI: 10.1039/C003301D , Communication 

Fe3O4 nanoparticles: a robust and magnetically recoverable catalyst for three-component coupling of aldehyde, alkyne and amine 
Tieqiang Zeng, Wen-Wen Chen, Ciprian M. Cirtiu, Audrey Moores, Gonghua Song and Chao-Jun Li 
Green Chem., 2010, 12, 570-573, DOI: 10.1039/B920000B , Communication 

Production of liquid hydrocarbon transportation fuels by oligomerization of biomass-derived C9 alkenes 
David Martin Alonso, Jesse Q. Bond, Juan Carlos Serrano-Ruiz and James A. Dumesic 
Green Chem., 2010, 12, 992-999, DOI: 10.1039/C001899F , Paper 

Technology development for the production of biobased products from biorefinery carbohydrates-the US Department of Energy’s “Top 10” revisited 
Joseph J. Bozell and Gene R. Petersen 
Green Chem., 2010, 12, 539-554, DOI: 10.1039/B922014C , Critical Review 

Green chemistry by nano-catalysis 
Vivek Polshettiwar and Rajender S. Varma 
Green Chem., 2010, 12, 743-754, DOI: 10.1039/B921171C , Tutorial Review 

Direct synthesis of hydrogen peroxide on palladium catalyst supported on sulfonic acid-functionalized silica 
Gema Blanco-Brieva, M. Pilar de Frutos Escrig, Jose M. Campos-Martin and Jose L. G. Fierro 
Green Chem., 2010, 12, 1163-1166, DOI: 10.1039/C003700A , Communication 

Why not take a look at the articles today and blog your thoughts and comments below.

Fancy submitting an article to Green Chemistry? Then why not submit to us today or alternatively email us your suggestions.

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