March 2012 – Organic & Biomolecular Chemistry Blog

Archive for March, 2012

There’s still time to join ICPOC21!

30 Mar 2012

Good news!

There’s still a chance to submit your oral abstract to ICPOC21: 21^st IUPAC International Conference on Physical Organic Chemistry to be held 9 – 13 September 2012 at Durham University.

The Scientific Committee is currently reviewing all submissions, and has agreed to accept contributions up to Friday 13 April to allow for the Easter holiday break.

Why join ICPOC21?

This meeting is organised by the Organic Division of the RSC on behalf of IUPAC. In addition to outstanding plenary sessions, there will be three parallel sessions over the five days comprising invited lectures and contributed talks, as well as poster sessions.

Key topics that will be covered in the meeting include:

• Physical underpinnings
• Mechanism and Catalysis
• Supramolecular and Systems Chemistry

A broad range of scientists from across the whole community who share a quantitative perspective on chemistry will be there, providing an opportunity to discuss and celebrate the current status, development, and the future of physical organic chemistry.

Make sure you are one of them! Don’t miss the oral abstract submission deadline – 13 April

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Take a stroll down memory lane with Organic & Biomolecular Chemistry on our 10th anniversary

29 Mar 2012

In our continued countdown to Organic & Biomolecular Chemistry‘s 10th anniversary issue we have had a look back at some of the art work that has appeared on our covers through the years. Below are the front covers of issue 1 and the work that featured on them for each year since the inception of OBC. What’s your favourite?

These stylish old school covers (right) were originally seen in 2003 & 2004 on volumes 1 & 2 respectively.

Volume 3:
Free: New chiral anion mediated asymmetric chemistry
Jérôme Lacour and Richard Frantz
Org. Biomol. Chem., 2005, 3, 15–19
DOI: 10.1039/B413554G

Volume 4:
Free: Artificial ribonucleases
Teija Niittymäki and Harri Lönnberg
Org. Biomol. Chem., 2006, 4, 15–25
DOI: 10.1039/B509022A

Volume 5:
Free: Synthesis of protein–polymer conjugates
Karina L. Heredia and Heather D. Maynard
Org. Biomol. Chem., 2007, 5, 45–53
DOI: 10.1039/B612355D

Volume 6:
Free: Metallo-nucleosides: synthesis and biological evaluation of hexacarbonyl dicobalt 5-alkynyl-2′-deoxyuridines
Craig D. Sergeant et al.

Org. Biomol. Chem., 2008, 6, 73–80
DOI: 10.1039/B713371E

Volume 7:
Free: Chemical approach toward efficient DNA methylation analysis
Akimitsu Okamoto
Org. Biomol. Chem., 2009, 7, 21–26
DOI: 10.1039/B813595A

Volume 8:
Free: Synthesis and biological evaluation of phosphatidylinositol phosphate affinity probes
Stuart J. Conway et al.

Org. Biomol. Chem., 2010, 8, 66–76
DOI: 10.1039/B913399B

Volume 9:
Free: Practical access to highly enantioenriched quaternary carbon Michael adducts using simple organocatalysts
Thomas C. Nugent, Mohammad Shoaib and Amna Shoaib
Org. Biomol. Chem., 2011, 9, 52–56
DOI: 10.1039/C0OB00822B

Volume 10:
Free: Synthesis of enantioenriched γ-quaternary cycloheptenones using a combined allylic alkylation/Stork–Danheiser approach: preparation of mono-, bi-, and tricyclic systems
Nathan B. Bennett et al.

Org. Biomol. Chem., 2012, 10, 56–59
DOI: 10.1039/C1OB06189E

All of these articles are FREE to access so if you missed them the first time round why not have a read now. In fact, why not have a look at the whole of the issue? All the content from each issue 1 is now FREE to access so dive in and enjoy:

Volume: 1 2 3 4 5 6 7 8 9 10

Do you have a favourite cover from our 10 years? Why not share it with us by leaving a comment below.

Interested in having your work featured on a cover? Submit your work to us and show us your artwork.

Missed our other 10th anniversary posts? Take a look here for some of our top cited work.

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OBC issue 16 has landed!

28 Mar 2012

The outside front cover of this week’s OBC is a communication from Barbara Zajcand colleagues at The City College and The City University of New York presenting a mild and efficient synthesis of 1-aryl-1-fluoroethenes from benzothiazolyl (aryl)fluoromethyl sulfones and paraformaldehyde, under DBU- or Cs₂CO₃-mediated conditions at room temperature.

Expedient synthesis of α-substituted fluoroethenes
Samir K. Mandal, Arun K. Ghosh, Rakesh Kumar and Barbara Zajc
Org. Biomol. Chem., 2012, 10, 3164–3167
DOI: 10.1039/C2OB07031F

The inside front cover is work from Keisuke Kato et al. at Toho University on the cyclization–carbonylation–cyclization coupling reaction of γ-propynyl-1,3-diketones catalysed by palladium(II)-bisoxazoline complexes to give symmetrical ketones bearing two oxabicyclic groups in moderate to excellent yields.

Cyclization–carbonylation–cyclization coupling reaction of γ-propynyl-1,3-diketones with palladium(II)-bisoxazoline catalyst
Taichi Kusakabe, Yasuko Kawai, Rong Shen, Tomoyuki Mochida and Keisuke Kato
Org. Biomol. Chem., 2012, 10, 3192–3194
DOI: 10.1039/C2OB07016B

Also in this issue:

Review:

Recent advances and applications of iridium-catalysed asymmetric allylic substitution by Paolo Tosatti and co-workers

Hot articles:

Electrophilicity of α-oxo gold carbene intermediates: halogen abstractions from halogenated solvents leading to the formation of chloro/bromomethyl ketones
Weimin He, Longyong Xie, Yingying Xu, Jiannan Xiang and Liming Zhang

Highly enantioselective [4 + 2] cycloadditions of allenoates and dual activated olefins catalyzed by N-acyl aminophosphines
Hua Xiao, Zhuo Chai, Dongdong Cao, Hongyu Wang, Jinghao Chen and Gang Zhao

Enantioselective synthesis of fluorene derivatives by chiral N-triflyl phosphoramide catalyzed double Friedel–Crafts alkylation reaction
Shou-Guo Wang, Long Han, Mi Zeng, Feng-Lai Sun, Wei Zhang and Shu-Li You

Hydrogen tunnelling influences the isomerisation of some small radicals of interstellar importance. A theoretical investigation
Tianfang Wang and John H. Bowie

See the rest HERE….

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HOT: Fluorene derivatives by chiral N-triflyl phosphoramide catalyzed double Friedel–Crafts alkylation

28 Mar 2012

In this addition to OBC‘s online Organocatalysis collection, Shu-Li You and co-workers from Shanghai Institute of Organic Chemistry report a highly efficient tandem double Friedel–Crafts reaction between indoles and 2-formylbiphenyl derivatives catalysed by chiral N-triflyl phosphoramide which produces various fluorene derivatives in excellent yields and ee.

Notably, the fluorene products obtained with the chiral N-triflyl phosphoramide have the opposite absolute configuration compared to that obtained with the corresponding chiral phosphoric acid. This allows access to both enantiomers of the products by utilizing different catalysts derived from one enantiomer of binaphthol.

This paper is FREE to access for 4 weeks, and while you’re there why not have a look at the rest of the Organoncatalysis collection.

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HOT: gold carbenes and halogen abstraction for chloro/bromomethyl ketones

26 Mar 2012

In this HOT communication Liming Zhang and colleagues at Hunan University demonstrate how α-oxo gold carbenes generated via intermolecular oxidation of terminal alkynes are highly electrophilic. So much so that they can effectively abstract halogens from halogenated solvents. They rationalise that this carbene is more electrophilic than related rhodium species due to the presence of only one α-carbonyl group, meaning it is less capable of back bonding.

Liming Zhang et al. believe that because of this differnece α-oxo gold carbenes may provide new opportunities for methodology development. To exemplify this they show that synthetically useful chloro/bromomethyl ketones can be prepared in one-step from terminal alkynes, avoiding the problems of poor regioselectivity and over-halogenation experienced by previous methods.

Sound interesting? Why not take a look, it’s FREE to access for the next 4 weeks.

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HOT: [4 + 2] cycloadditions of allenoates and dual activated olefins with N-acyl aminophosphines

26 Mar 2012

Gang Zhaoet al. from University of Science and Technology of China present highly diastereoselective and enantioselective [4 + 2] cycloadditions between allenoates and dual activated olefins catalyzed by bifunctional N-acyl aminophosphine catalysts.

To demonstrate the potential of the N-acyl aminophosphine catalysts in asymmetric phosphine mediated reactions, Gang Zhao et al. have prepared a range of synthetically valuable cyclohexene structures based on α-substituted buta-2,3-dienoates, which bear three contiguous chiral centers with good to excellent diastereoselectivities and enantioselectivities.

Take a look and let us know what you think!

This HOT OBC article will be free to access for the next 4 weeks.

Highly enantioselective [4 + 2] cycloadditions of allenoates and dual activated olefins catalyzed by N-acyl aminophosphines
Hua Xiao, Zhuo Chai, Dongdong Cao, Hongyu Wang, Jinghao Chen and Gang Zhao
Org. Biomol. Chem., 2012,
DOI: 10.1039/C2OB25295C

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Picking out cysteine for health study

23 Mar 2012

A highly selective indicator for the amino acid cysteine has been designed by scientists from the US and China to monitor levels in human plasma. Elevated cysteine levels have been linked with motor neurone disease, Parkinson’s disease and Alzheimer’s disease.

Cysteine is an essential amino acid and plays an important role in cell functions. Its structure contains both a sulfhydryl (-SH) and an amino group (-NH₂), both of which are reactive. Previous detectors have focused on reactions with the sulfhydryl group, but it has been tricky to detect cysteine over other SH-containing biomolecules in the blood, such as glutathione and the closely related homocysteine.

Row of sample vials with a blank control (clear and colourless), cysteine (pink), homocysteine (clear and colourless) and glutathione (clear and colourless)

The indicator molecule reacts with the sulfhydryl and amino parts of the cysteine molecule to form a pink compound that's fluorescent under UV light. No such reaction is seen with other biothiols

Robert Strongin from Portland State University, Portland, and co-workers, have found a way to overcome this problem, by designing a fluorescent sensor called a chemodosimeter (so called because the visible change is due to an irreversible reaction). They used an indicator molecule that reacts with both the sulfhydryl and amino parts of the cysteine molecule.

‘We can detect cysteine selectively due to its unique chemistry, which we have complemented with our indicator design,’ explains Strongin. ‘There is a very selective reaction that turns the indicator on.’ The cysteine’s sulfhydryl group reacts with the indicator molecule to form a colourless compound. The amino part attacks an ester group on the indicator molecule to form a pink compound that is fluorescent under UV light. When tested with other amino acids or SH-containing molecules, no colour change or fluorescence could be seen.

‘Compared to designing probes for the detection of metal ions or inorganic anions, analytes such as cysteine tend to be far more problematic. The work provides convincing evidence that a clever design can overcome such obstacles,’ says Michael Heagy, an expert in fluorescent chemosensors for biological molecules at the New Mexico Institute of Mining and Technology, US.

In the future, Strongin plans to develop the approach to make other specialised indicators for non-polar metabolites, such as amino acids, sugars and phospholipids.

A seminaphthofluorescein-based fluorescent chemodosimeter for the highly selective detection of cysteine
Xiaofeng Yang , Yixing Guo and Robert M. Strongin
DOI: 10.1039/C2OB25178G

Read the original article at Chemistry World

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Organic & Biomolecular Chemistry International Symposium

22 Mar 2012

The first Organic & Biomolecular Chemistry International Symposium will take place in China in April 2012. The symposium will be comprised of three one-day meetings, each one featuring a selection of lectures covering organic and bioorganic chemistry by some of the world’s leading international scientists.

The meetings will be held at Shanghai Institute of Organic Chemistry, Lanzhou University and Peking University. The symposium is organised by Organic & Biomolecular Chemistry, the Royal Society of Chemistry and the local host organisations. The OBC International Symposium will take place as follows:
• Monday 16th April 2012 – Shanghai Institute of Organic Chemistry, Shanghai, China
• Wednesday 18th April 2012 – Lanzhou University, Lanzhou, China
• Friday 20th April 2012 – Peking University, Beijing, China

For more information please visit the symposium website.

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An aerobic copper relay race and pharmacological chaperones for Gaucher disease treatment on the OBC covers

21 Mar 2012

This week’s issue of OBC features art work from Qing Xu and Xin-Shan Ye et al.

Qing Xu and colleagues from Wenzhou University have developed a green copper catalyzed N-alkylation method for various amides and amines with alcohols, employing aerobic oxidation of the alcohols to aldehydes for a more effective way of activating the alcohols. This advantageous method uses a ligand-free catalyst and its only byproduct is water!

Copper-catalyzed N-alkylation of amides and amines with alcohols employing the aerobic relay race methodology
Qiang Li, Songjian Fan, Qing Sun, Haiwen Tian, Xiaochun Yu and Qing Xu
Org. Biomol. Chem., DOI: 10.1039/C1OB06743E

Xin-Shan Ye and co-workers at Peking University and University of Oxford have designed a concise route to a series of N-substituted ε-hexonolactams employing a tandem ring-expansion as the key step. These novel N-alkylated iminosugars are promising pharmacological chaperones for the treatment of N370S mutant Gaucher disease.

Synthesis of N-substituted ε-hexonolactams as pharmacological chaperones for the treatment of N370S mutant Gaucher disease
Guan-Nan Wang, Gabriele Twigg, Terry D. Butters, Siwei Zhang, Liangren Zhang, Li-He Zhang and Xin-Shan Ye
Org. Biomol. Chem., DOI: 10.1039/C2OB06987C

Both of these articles can be accessed for free for the next 6 weeks!

Other interesting articles in this issue are:

A perspective by Alfredo Ricci et al. about bioinspired organocatalytic asymmetric reactions

and 2 HOT articles which are free to access for the next 4 weeks:

Fluorimetric detection of Mg²⁺and DNA with 9-(alkoxyphenyl)benzo[b]quinolizinium derivatives
Maoqun Tian, Heiko Ihmels and Shite Ye
Org. Biomol. Chem., DOI: 10.1039/C2OB06948B

Substituted oxines inhibit endothelial cell proliferation and angiogenesis
Shridhar Bhat, Joong Sup Shim, Feiran Zhang, Curtis Robert Chong and Jun O. Liu
Org. Biomol. Chem., DOI: 10.1039/C2OB06978D

If you liked those why not view the rest of the issue HERE!

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