Coupling of unactivated aldehydes and Anticancer activity of oleanolic acid derivatives on the cover of OBC issue 11

Welcome to OBC issue 11, 2012 

Oscar Navarro and colleagues at the University of Hawaii at Manoa have used well-defined (N-heterocyclic carbene)–Ag(I) complexes for the A3 reaction, thereby allowing for the coupling of unactivated aldehydes at room temperature with very short reaction times. This work is featured on OBC‘s outside front cover, showcasing a scheme of the reaction depicted in their article over a picture of the coast of Lanikai, in Hawaii.

Well-defined (N-heterocyclic carbene)–Ag(I) complexes as catalysts for A3 reactions
Ming-Tsz Chen, Brant Landers and Oscar Navarro 
DOI: 10.1039/C2OB06900H 

The inside front cover illustrates work by Barbara Bednarczyk–Cwynar et al. at Poznan University of Medical Sciences, Poland, who highlight the strong cytotoxic activity on KB, MCF-7 and HeLa cell lines of novel A-ring or/and C-ring modified methyl oleanolate derivatives.

Anticancer effect of A-ring or/and C-ring modified oleanolic acid derivatives on KB, MCF-7 and HeLa cell lines
Barbara Bednarczyk–Cwynar, Lucjusz Zaprutko, Piotr Ruszkowski and Bogusław Hładoń
DOI: 10.1039/C2OB06923G

Interested? Why not read both communications, they are FREE to access for the next 6 weeks.

 

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Countdown to OBC’s 10th anniversary continues with tin and aluminium!

Continuing our countdown to OBC’s 10th anniversary issue, we’ve collected together 10 tin and aluminium related articles published in the journal. Why? An old tradition in the UK is to give gifts of made of symbolic materials on significant wedding anniversaries, and the metals associated with a 10th wedding anniversary are tin and aluminium. Now, we don’t have any trinkets for you, but why not take a look at some of these interesting tin and aluminium-themed articles!

Effective 1,5-, 1,6- and 1,7-remote stereocontrol in reactions of alkoxy- and hydroxy-substituted allylstannanes with aldehydes
John S. Carey, Somhairle MacCormick, Steven J. Stanway, Aphiwat Teerawutgulrag and Eric J. Thomas
DOI: 10.1039/C0OB01084G

A selective, cell-permeable fluorescent probe for Al3+ in living cells
Lina Wang, Wenwu Qin, Xiaoliang Tang, Wei Dou, Weisheng Liu, Qingfeng Teng and Xiaojun Yao
DOI: 10.1039/C0OB00123F, Paper

Microwave-assisted regioselective ring opening of non-activated aziridines by lithium aluminium hydride
Sonja Stanković, Matthias D’hooghe and Norbert De Kimpe
DOI: 10.1039/C004960C

Synthesis of Biginelli dihydropyrimidinone derivatives with various substituents on aluminium-planted mesoporous silica catalyst
Hiroaki Murata, Haruro Ishitani and Masakazu Iwamoto
DOI: 10.1039/B920821F, Paper

Intramolecular carbolithiation reactions for the preparation of 3-alkenylpyrrolidines
Iain Coldham, Kathy N. Price and Richard E. Rathmell
DOI: 10.1039/B303670G

Rapid methylation on carbon frameworks useful for the synthesis of 11CH3-incorporated PET tracers: Pd(0)-mediated rapid coupling of methyl iodide with an alkenyltributylstannane leading to a 1-methylalkene
Takamitsu Hosoya, Kengo Sumi, Hisashi Doi, Masahiro Wakao and Masaaki Suzuki
DOI: 10.1039/B515215A

Aluminium triflate: a remarkable Lewis acid catalyst for the ring opening of epoxides by alcohols
D. Bradley G. Williams and Michelle Lawton
DOI: 10.1039/B508924G

Cyclizative radical carbonylations of azaenynes by TTMSS and hexanethiol leading to α-silyl- and thiomethylene lactams. Insights into the E/Z stereoselectivities
Mami Tojino, Noboru Otsuka, Takahide Fukuyama, Hiroshi Matsubara, Carl H. Schiesser, Hiroki Kuriyama, Hironari Miyazato, Satoshi Minakata, Mitsuo Komatsu and Ilhyong Ryu
DOI: 10.1039/B309944J

Photochemical intramolecular aromatic substitutions of the imidazol-2-yl radical are superior to those mediated by Bu3SnH
Mairéad A. Clyne and Fawaz Aldabbagh
DOI: 10.1039/B512729G

On the use of mixtures of organotin species for catalytic enantioselective ketone allylation—a detective story
Anthony Cunningham, Vijaya Mokal-Parekh, Claire Wilson and Simon Woodward
DOI: 10.1039/B313384B

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

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Top ten most accessed articles in December

This month sees the following articles in Organic & Biomolecular Chemistry that are in the top ten most accessed:

Is nevirapine atropisomeric? Experimental and computational evidence for rapid conformational inversion
Edmund W. D. Burke, Gareth A. Morris, Mark A. Vincent, Ian H. Hillier and Jonathan Clayden
Org. Biomol. Chem., 2012, 10, 716-719
DOI: 10.1039/C1OB06490H

A one-pot catalysis: the strategic classification with some recent examples
Nitin T. Patil, Valmik S. Shinde and Balakrishna Gajula
Org. Biomol. Chem., 2012, 10, 211-224
DOI: 10.1039/C1OB06432K

N-Heterocyclic carbene catalysed aerobic oxidation of aromatic aldehydes to aryl esters using boronic acids
Panjab Arde, B. T. Ramanjaneyulu, Virsinha Reddy, Apurv Saxena and R. Vijaya Anand
Org. Biomol. Chem., 2012, 10, 848-851
DOI: 10.1039/C1OB06566A

Direct preparation of thiazoles, imidazoles, imidazopyridines and thiazolidines from alkenes
Timothy J. Donohoe, Mikhail A Kabeshov, Akshat H. Rathi and Ian E. D. Smith
Org. Biomol. Chem., 2012, 10, 1093-1101
DOI: 10.1039/C1OB06587D

Towards the systematic exploration of chemical space
Mark Dow, Martin Fisher, Thomas James, Francesco Marchetti and Adam Nelson
Org. Biomol. Chem., 2012, Advance Article
DOI: 10.1039/C1OB06098H

Fluoride-selective optical sensor based on the dipyrrolyl-tetrathiafulvalene chromophore
Shadi Rivadehi, Ellen F. Reid, Conor F. Hogan, Sheshanath V. Bhosale and Steven J. Langford
Org. Biomol. Chem., 2012, 10, 705-709
DOI: 10.1039/C1OB06459B

Syntheses of furo[3,4-c]coumarins and related furyl coumarin derivatives via intramolecular Wittig reactions
Yeong-Jiunn Jang,  Siang-en Syu,  Yu-Jhang Chen,  Mei-Chun Yang and Wenwei Lin
Org. Biomol. Chem., 2012, 10, 843-847
DOI: 10.1039/C1OB06571H

Synthesis and biological activity of phosphonoacetate- and thiophosphonoacetate-modified 2′-O-methyl oligoribonucleotides
Richard N. Threlfall, Adrian G. Torres, Angelika Krivenko, Michael J. Gait and Marvin H. Caruthers
Org. Biomol. Chem., 2012, 10, 746-754
DOI: 10.1039/C1OB06614E

C–H functionalization of tertiary amines by cross dehydrogenative coupling reactions: solvent-free synthesis of α-aminonitriles and ß-nitroamines under aerobic condition
Kaliyamoorthy Alagiri and Kandikere Ramaiah Prabhu
Org. Biomol. Chem., 2012, 10, 835-842
DOI: 10.1039/C1OB06466E

Calixarene-induced aggregation of perylene bisimides
Dong-Sheng Guo,  Bang-Ping Jiang,  Xiang Wang and Yu Liu
Org. Biomol. Chem., 2012, 10, 720-723
DOI: 10.1039/C2OB06973C

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

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

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Collagen triple helices and click chemisry on the cover of OBC issue 10

Welcome to OBC issue 10!

OBC‘s cover this week features work by Helma Wennemers et al. at the University of Basel (Switzerland), who have used click chemistry to introduce moieties as sterically demanding as monosaccharides into the Yaa position of collagen model peptides, and studied the effect of different triazolyl derivatives as well as the configuration of the functionalized proline residue on the thermal stability of the collagen triple helices.

Conformational stability of collagen triple helices functionalized in the Yaa position by click chemistry

Roman S. Erdmann and Helma Wennemers
Org. Biomol. Chem., 2012, 10, 1982-1986
DOI: 10.1039/C2OB06720J

As with all of our cover articles, it will be FREE to access for the next 6 weeks

This article is part of OBC‘s web-themed issue on Foldamer Chemistry – View the full collection of articles here

The issue also contains:

three ‘Hot Articles’

and that’s just a taster… we hope you enjoy the whole issue!

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Top 10 Perspective articles from Organic & Biomolecular Chemistry

Now bringing you the top 10 most cited Perspectives ever – take a look!

Continuing with our countdown to OBC’s 10th anniversary celebratory issue we’ve made the top cited* Perpsective articles from the journal free to access for one week:

1. Recognition and activation by ureas and thioureas: stereoselective reactions using ureas and thioureas as hydrogen-bonding donors
Yoshiji Takemoto
DOI: 10.1039/B511216H

2. Bifunctional transition metal-based molecular catalysts for asymmetric syntheses
Takao Ikariya,  Kunihiko Murata and Ryoji Noyori
DOI: 10.1039/B513564H

3. Analysis of the reactions used for the preparation of drug candidate molecules
John S. Carey,  David Laffan, Colin Thomson and Mike T. Williams
DOI: 10.1039/B602413K

4. Density functional theory with dispersion corrections for supramolecular structures, aggregates, and complexes of (bio)organic molecules
Stefan Grimme,  Jens Antony, Tobias Schwabe and Christian Mück-Lichtenfeld
DOI: 10.1039/B615319B

5. Mechanistic aspects of transition metal catalysed 1,6-diene and 1,6-enyne cycloisomerisation reactions
Guy C. Lloyd-Jones
DOI: 10.1039/B209175P

6. Multivalency in supramolecular chemistry and nanofabrication
Alart Mulder,  Jurriaan Huskens and David N. Reinhoudt
DOI: 10.1039/B413971B

7. Porphyrin–fullerene linked systems as artificial photosynthetic mimics
Hiroshi Imahori
2004, DOI: 10.1039/B403024A

8. Ru complexes bearing bidentate carbenes: from innocent curiosity to uniquely effective catalysts for olefin metathesis
Amir H. Hoveyda,  Dennis G. Gillingham,  Joshua J. Van Veldhuizen,  Osamu Kataoka,  Steven B. Garber,  Jason S. Kingsbury and Joseph P. A. Harrity
DOI: 10.1039/B311496C

9. Molecular similarity: a key technique in molecular informatics
Andreas Bender and Robert C. Glen
DOI: 10.1039/B409813G

10. DNA-programmed assembly of nanostructures
Kurt V. Gothelf and Thomas H. LaBean
DOI: 10.1039/B510551J

  • Interested in joining in with a Perspective article for OBC? Why not get in contact – we’d love to hear your ideas.

*Top cited Perspective articles according to ISI on the 1st of February 2012

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Chameleons and catalysis on the cover of the latest issue of OBC

The colourful images on our covers are from Andrew C. Benniston and Ming-Hua Xu et al.

Andrew Benniston (University of Newcastle) together with colleagues from Istanbul Technical University and Hacettepe University, Turkey have created a series of colour-responsive fluorescent fluorene-fused benzoquinones with potential for use as reactive oxygen species sensors.  One of the compounds synthesised exhibits ‘chameleon-like’ behaviour switching from red to blue fluorescence on reduction, and reverts back to red on reaction with ROSs.

Colour-responsive fluorescent oxy radical sensors
Baris Yucel, Bahar Sanli, Huseyin Akbulut, Suheyla Ozbey and Andrew C. Benniston
DOI: 10.1039/C2OB06825G

Ming-Hua Xu and colleagues at Shanghai Institute of Materia Medica have designed a structurally simple new class of chiral sulfur–olefin hybrid ligands – N-cinnamyl sulfinamides – for use in asymmetric catalysis. The ligands where tested in rhodium-catalyzed asymmetric 1,4-addition reactions, converting aryl boronic acids to α,β-unsaturated carbonyl compounds with up to 99% yield and 98% ee.

Design of N-cinnamyl sulfinamides as new sulfur-containing olefin ligands for asymmetric catalysis: achieving structural simplicity with a categorical linear framework
Shen-Shuang Jin, Hui Wang, Ting-Shun Zhu and Ming-Hua Xu
DOI: 10.1039/C2OB06723D

This issue also contains a review on the recognition properties of imidazole derivatives by Franscico Otón et al. and a hot article from Luis Simón and Jonathan Goodman on hydrogen-bond stabilization in oxyanion holes, showing that the 3D arrangement, rather than planar arrangement, of H-bonds stabilises oxyanion holes.

View the issue

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Review on microwave synthesis of small molecules to target TB, HIV/AIDS, malaria and hepatitis C

Mats Larhed and colleagues from the University of Uppsala provide an extremely accessible introduction to microwave synthesis in this review article, demonstrating the use of single-mode microwave synthesis for laboratory-scale preparation of small molecules.  They focus of the synthesis of potential treatments of four of the world’s most infectious diseases; tuberculosis, HIV/AIDS, malaria and hepatitis C.


Microwave-assisted synthesis of small molecules targeting the infectious diseases tuberculosis, HIV/AIDS, malaria and hepatitis C
Johan Gising, Luke R. Odell and Mats Larhed
DOI: 10.1039/C2OB06833H

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Building a nation of scientists

An interview with Goverdhan Mehta, former president of the International Council for Science

Goverdhan Mehta talks to Sheena Elliott and Elinor Richards about the progress of science in India and the challenges scientists face

Goverdhan Mehta is a researcher, specialising in organic synthesis. He has helped to build institutions in India – the Indian Institute of Technology, Kanpur, the University of Hyderabad, and the Indian Institute of Science, Bangalore. He was director of the Indian Institute of Science (1998-2005) and vice chancellor of the University of Hyderabad (1994-1998).

Your research is focused on organic chemistry. What attracted you to that field?

There is something intrinsically fascinating about organic chemistry. In my early high school years, when I was exposed to interesting chemical structures, I was attracted to them. I had a sense of appreciation for art and organic molecules to me provided a wonderful expression of art at a molecular level.

What are your main achievements in the field?

I have worked in many areas of organic chemistry, but it’s synthesis that’s given me the greatest pleasure. As organic chemistry advanced, different contemporary challenges came to my attention. The main driver for me to pursue those challenges was the intricacy of the target structure synthesis. There was also an element of expectation that perhaps our research might become useful to society. We continue to need new drugs for a variety of disorders, so we synthesised a large number of natural products; many of them are biologically active and it is quite possible that some of them can provide leads for new drug discovery.

Over the last few years, I have become interested in how to address a problem that the ageing population is facing – neurodegeneration. It has been shown that some natural products can slow down neurodegeneration. In some cases, there is also an indication that they can help restore lost cognitive function. So I have been working on the synthesis of such lead molecules. As I’m getting older, I recognise the need for doing something in that area!

You’ve won numerous awards. Which achievements are you most proud of?

I don’t think that awards and recognition have necessarily brought me a great sense of joy. They do bring a sense of satisfaction because your peers have recognised your work. But I don’t think any serious researcher works for awards. It is the sheer joy of research that keeps people going. Recognition has come my way, but don’t think that I can equate that with the joy of doing research.

What are the challenges facing scientists in India and how could these be overcome?

Scientists all over the world are facing challenges on two fronts. The first problem is that scientists are not being supported by society as much as they should and some governments are not always forthcoming in terms of providing budgetary support. The second problem is that scientists, and science in general, have become isolated both in terms of discipline and, to some extent, in terms of geographical location. This is being redressed now with increasing international collaborations, so in the geographical sense, the isolation is being reduced. But I think disciplinary isolation vis a vis other knowledge streams and fragmentation of science is still a serious challenge.

It is a good time for scientists in India because the government is very supportive of science. Funding is no longer as serious a problem as it is in other parts of the world. Recently, our prime minister said that the budget for science will be almost doubled over the next few years. But I’m not too sure that we as a scientific community are steering science in India in the direction that it ought to be heading. I believe that the government and the scientific community must set a goal that in the next 10 years, India will be among the world’s leading scientific countries.

What is your opinion on the perception that Indian science and research is falling behind the rest of the world, following recent comments by Prime Minister Manmohan Singh?

Prime Minister Singh’s statement referred mainly to China. China has made more progress in science and technology than India. Scientific productivity in India has increased, but not as much as in China. Since we are behind, to simply say that we are walking and walking well is not enough. We should be galloping to catch up. My judgement is that our progress is not commensurate with the support that the government is providing, and not commensurate with the capacity, capability, enthusiasm and the vibrancy that our youth have. We can achieve much more.

How do the different industries compare (the pharmaceutical industry in particular or the more general chemical industry)?

It is only over the last 10 or 12 years, since the economic reforms, that industry in India has grown at such a rate so as to be in a position to invest in research and development. I expect that investment by industry is going to rise; however, the current level of investment is not in an acceptable range. There are certain sectors – pharma, for example – and some other chemical industries, where I think India’s potential is immense, but there are some challenges with the policies that are being pursued. We have to devise a well thought out strategy.

The prime minister’s Science Advisory Council reported that there in an absence of any Indian universities among the world’s best. What is your opinion on the quality of universities in India?

I’m not a great believer in the ranking systems being followed, but the fact is that no Indian university features among the top few hundred  universities. However, if we were to look at undergraduate teaching, India has institutions that produce graduates through excellent teaching and training. The graduates are probably as good as they are anywhere else in the world. If you were to grade an institution on the quality of undergraduates, I would say that the Indian Institutes of Technology rank among the top 10 institutions in the world. But, if you bring in research and other elements, they will not feature anywhere near the top. So the quality of research is a serious problem. I think it is high time that the scientific community and scientific leadership in our country sort out an effective, implementable strategy to make a major shift.

You experienced difficulty obtaining a visa to travel to the US in 2006, when you were invited to give a lecture at the University of Florida. At the time, a report from the National Academy of Sciences in the US said that at least 3000 scientists had faced a similar problem. Have things improved since then or do you believe that the visa problem is hampering scientific progress and career development for scientists?

It was ironic that I and a leading scientist from the US, Jane Lubchenco (who at that time was president of the International Council for Science before I succeeded her), wrote an editorial about the principle of universatility of science and the visa regime in Science a few months before this happened. We wrote that it was important for the international growth of science that scientists were able to travel. Little did I realise that soon I would be a victim of this! I think the situation has improved, but a lot more needs to be done. While the US National Academy of Sciences is playing a very positive role towards this end, the academies can only do the advocacy. Eventually, it is the government and the state department of security staff that makes the final judgement.

If you have any spare time, how do you fill it?

For most scientists, and I’m no exception, your research is a hobby. What other profession can give you that pleasure and privilege? In a previous interview, I was asked what I would wish for. I said we Indians believe in rebirth and so the only wish I have is that if I were to be born again, I would be a scientist. I would like to be a chemist, hopefully a better one.

Read some of Goverdhan Mehta’s recent research:

Towards a temperature-guided molecular switch: an unusual reversible low-temperature polymorphic phase transition in a conformationally locked environment
Goverdhan Mehta and Saikat Sen, Chem. Commun., 2009, 5981
DOI: 10.1039/b905651c

Understanding the self-assembling process in crystalline cyclooctitols: an insight into the conformational flexibility of medium-sized rings
Goverdhan Mehta, Saikat Sen and Kotapalli Pallavi, CrystEngComm, 2008, 10, 534
DOI: 10.1039/b712877k

Additive induced polymorphous behavior of a conformationally locked hexol
Goverdhan Mehta, Saikat Sen and Kailasam Venkatesan, CrystEngComm, 2007, 9, 144
DOI: 10.1039/b613949c

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Top 10 Emerging Area articles from Organic & Biomolecular Chemistry

OBC celebrates its 10th year of publication in 2012, so over the coming weeks we’ll be bringing you some of the ‘Top 10’s’ from the journal – keep checking back for more!

Continuing with our countdown to OBC’s 10th anniversary celebratory issue we’ve made the top cited Emerging Area articles from the journal free to access for one week:

Asymmetric organocatalysis
Jayasree Seayad and Benjamin List
DOI: 10.1039/B415217B

The golden gate to catalysis
Anja Hoffmann-Röder and Norbert Krause
DOI: 10.1039/B416516K

Organocatalysis: asymmetric cascade reactions catalysed by chiral secondary amines
Xinhong Yu and Wei Wang
DOI: 10.1039/B800245M

A hitchhiker’s guide to G-quadruplex ligands
David Monchaud and Marie-Paule Teulade-Fichou
DOI: 10.1039/B714772B

Advanced organic synthesis using microreactor technology
Batoul Ahmed-Omer, Johan C. Brandt and Thomas Wirth
DOI: 10.1039/B615072A

Diversity-oriented synthesis; a challenge for synthetic chemists
David R. Spring
DOI: 10.1039/B310752N

“Frustrated Lewis pairs”: a concept for new reactivity and catalysis
Douglas W. Stephan
DOI: 10.1039/B802575B

Synthesis of protein–polymer conjugates
Karina L. Heredia and Heather D. Maynard
DOI: 10.1039/B612355D

Catalytic asymmetric hydroamination of non-activated olefins
Kai C. Hultzsch
DOI: 10.1039/B418521H

Out of the oil bath and into the oven—microwave-assisted combinatorial chemistry heats up
Helen E. Blackwell
DOI: 10.1039/B301432K

Want to write a new emerging area that you think is going to be big in the future? Why not get in contact – we’d love to hear your ideas.

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Mouth bacteria makes metabolite that could prevent yeast infections

A bacteria present in the mouth – Streptococcus mutans – has been shown to generate the metabolite mutanobactin A by scientists from the US. They found that the metabolite inhibits biofilms formed by the fungal oral pathogen Candida albicans, which causes yeast infections.

In biofilms, pathogens are less susceptible to antibiotics, so this finding could have implications for treating yeast infections.

Fungal biofilm inhibitors from a human oral microbiome-derived bacterium
Xiaoru Wang, Lin Du, Jianlan You,  Jarrod B. King and Robert H. Cichewicz
DOI: 10.1039/C2OB06856G

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