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Cyanide test for cassava

27 Oct 2014

A new sensing system that changes colour to indicate if a cassava-based foodstuff is safe to eat by checking for hydrogen cyanide has been devised by researchers in Switzerland and Mozambique.

Cassava, an edible root that grows well in poor conditions, is the third largest source of calories for people in the tropics. However, as a self-defence mechanism against attack from pests and predators, cassava releases hydrogen cyanide upon damage to its cells. Sun-drying, fermentation and other traditional processing techniques can successfully eliminate the hydrogen cyanide but it may remain and cause a variety of illnesses, including tropical ataxic neuropathy and epidemic spastic paraparesis, if pre-consumption treatment is substandard…..

Read the full article in Chemistry World»

Read the original journal article in Organic & Biomolecular Chemistry – it’s free to access until 4 December:
Corrin-based chemosensors for the ASSURED detection of endogenous cyanide
Felix Zelder and Lucas Tivana
DOI: 10.1039/C4OB01889C

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Diversification of a Multicomponent Reaction

15 Oct 2014

The Ugi reaction was one of the very first multicomponent reactions exploited to develop chemical libraries, which further extended to combinatorial, solid phase and flow synthesis for evolving new lead structures of active agents. Implementing the Ugi reaction in combination with other organic reactions enlarges the chemical diversity of possible products.

Researchers at Vrije University Brussel, led by Steven Ballet, have made a step forward by executing a one-pot Ugi-Huisgen tandem reaction and found an alternative high atom economy pathway for the synthesis of conformationally constrained, amino-triazoloazepinone-containing di- and tripeptides.

Strategically, they have used an unconventional azide containing acid, and alkyne amine along with traditional aldehydes and isocyanides. By using equimolar reactants with very mild reaction conditions, they were able to observe total conversion to the linear Ugi-compounds equipped with azide and alkyne functionality. Furthermore, they have cyclised the resulting compounds into the respective triazoles, by performing a catalyst-free Huisgen cycloaddition reaction in a sealed tube.

Variation in substitution patterns and tolerance of a large array of aldehydes in this methodology will open a new avenue for the synthesis of various building blocks to be used in peptidomimetics with a wide range of applications.

Find out more in their Communication:

Efficient synthesis of conformationally constrained, amino-triazoloazepinone-containing di- and tripeptides via a one-pot Ugi–Huisgen tandem reaction
T. M. A. Barlow, M. Jida, D. Tourwéa and S. Ballet
DOI: 10.1039/C4OB01381F

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Q2 Top Ten most accessed articles

01 Oct 2014

During the months April – June 2014, the most downloaded Organic & Biomolecualr Chemistry articles were:

Design, synthesis, and application of tartaric acid derived N-spiro quaternary ammonium salts as chiral phase-transfer catalysts
Mario Waser, Katharina Gratzer, Richard Herchl and Norbert Müller
DOI: 10.1039/C1OB06573D

Far-red and near infrared BODIPY dyes: synthesis and applications for fluorescent pH probes and bio-imaging
Yong Ni and Jishan Wu
DOI: 10.1039/C3OB42554A

Direct acylation of N-benzyltriflamides from the alcohol oxidation level via palladium-catalyzed C–H bond activation
Jihye Park, Aejin Kim, Satyasheel Sharma, Minyoung Kim, Eonjeong Park, Yukyoung Jeon, Youngil Lee, Jong Hwan Kwak, Young Hoon Jung and In Su Kim
DOI: 10.1039/C3OB40140E

sp³ C–H oxidation by remote H-radical shift with oxygen- and nitrogen-radicals: a recent update
Shunsuke Chiba and Hui Chen
DOI: 10.1039/C4OB00469H

Watsonianone A–C, anti-plasmodial β-triketones from the Australian tree, Corymbia watsoniana
Anthony R. Carroll, Vicky M. Avery, Sandra Duffy, Paul I. Forster and Gordon P. Guymer
DOI: 10.1039/C2OB26931G

Recent advances in biocompatible nanocarriers for delivery of chemotherapeutic cargoes towards cancer therapy
Chung Yen Ang, Si Yu Tan and Yanli Zhao
DOI: 10.1039/C4OB00164H

Continuous flow chemistry: a discovery tool for new chemical reactivity patterns
Jan Hartwig, Jan B. Metternich, Nikzad Nikbin, Andreas Kirschning and Steven V. Ley
DOI: 10.1039/C4OB00662C

Bifunctional primary amine-thioureas in asymmetric organocatalysis
Olga V. Serdyuk, Christina M. Heckel and Svetlana B. Tsogoeva
DOI: 10.1039/C3OB41403E

Palladium-catalyzed three-component reaction of N-tosylhydrazone, norbornene and aryl halide
Fangdong Hu, Ying Xia, Zhenxing Liu, Chen Ma, Yan Zhang and Jianbo Wang
DOI: 10.1039/C4OB00590B

A coumarin-quinolinium-based fluorescent probe for ratiometric sensing of sulfite in living cells
Li Tan, Weiying Lin, Sasa Zhu, Lin Yuan and Kaibo Zheng
DOI: 10.1039/C4OB00132J

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Winners at the 25th Symposium on Physical Organic Chemistry

25 Sep 2014

From left to right: Professor Yoshito Tobe (President) Mr. Tomoya Nakamura (OBC) Mr. Yuta Shiina (RSC Advances) Mr. Hirotaka Mori (Chemical Science) Hiroyuki Isobe (Organizer)

Congratulations to the winners of the poster prizes at the 25th Symposium on Physical Organic Chemistry (Japan), which was held September 7th to September 9th in Sendai.

Organic & Biomolecular Chemistry prize: Mr. Tomoya Nakamura (Supervisor: Professor Eiichi Nakamura), Department of Chemistry, The University of Tokyo
Title: Benzodipyrrole-Based Donor-Acceptor Type Boron Complexes for Near-Infrared Absorption

RSC Advances prize: Mr. Yuta Shiina (Supervisor: Professor Nagao Kobayashi), Department of Chemistry, Tohoku University
Title: Redox-control of Molecular Alignment of TTF-Annulated Silicon Phthalocyanine Oligomers

Chemical Science prize: Mr. Hirotaka Mori (Supervisor: Professor Atsuhiro Osuka), Department of Chemistry, Kyoto University
Title: Synthesis and Properties of 5,20-α-Oligothienyl-substitued [26]Hexaphyrins

The event organised by the Society of Physical Organic Chemistry, Japan, saw 624 participants attend, with 2 keynote lectures from E. Nakamura & C. Nuckolls. In addition there were 328 poster presentations, and 96 oral presentations.

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HOT Organic & Biomolecular Chemistry articles

19 Sep 2014

Check out the following HOT articles, as recommened by the reviewers of the articles. These have all been made free to access until 20th October:

Estimating the shape and size of supramolecular assemblies by variable temperature diffusion ordered spectroscopy
Benjamin M. Schulze, Davita L. Watkins, Jing Zhang, Ion Ghiviriga and Ronald K. Castellano
DOI: 10.1039/C4OB01373E, Communication

Evolution of a strategy for preparing bioactive small molecules by sequential multicomponent assembly processes, cyclizations, and diversification
James J. Sahn, Brett A. Granger and Stephen F. Martin
DOI: 10.1039/C4OB00835A, Review Article
From themed collection In Celebration of Richard Taylor’s 65^th Birthday

Development and mechanistic studies of an optimized receptor for trimethyllysine using iterative redesign by dynamic combinatorial chemistry
Nicholas K. Pinkin and Marcey L. Waters
DOI: 10.1039/C4OB01249F, Paper

Modulation of DNA–polyamide interaction by β-alanine substitutions: a study of positional effects on binding affinity, kinetics and thermodynamics
Shuo Wang, Karl Aston, Kevin J. Koeller, G. Davis Harris, Nigam P. Rath, James K. Bashkin and W. David Wilson
DOI: 10.1039/C4OB01456A, Paper

Iridium-catalyzed C–H borylation of pyridines
Scott A. Sadler, Hazmi Tajuddin, Ibraheem A. I. Mkhalid, Andrei S. Batsanov, David Albesa-Jove, Man Sing Cheung, Aoife C. Maxwell, Lena Shukla, Bryan Roberts, David C. Blakemore, Zhenyang Lin, Todd B. Marder and Patrick G. Steel
DOI: 10.1039/C4OB01565G, Paper

Efficient synthesis of conformationally constrained, amino-triazoloazepinone-containing di- and tripeptides via a one-pot Ugi–Huisgen tandem reaction
T. M. A. Barlow, M. Jida, D. Tourwé and S. Ballet
DOI: 10.1039/C4OB01381F, Communication

Influence of B-ring modifications on proton affinity, transmembrane anion transport and anti-cancer properties of synthetic prodigiosenes
Estelle Marchal, Soumya Rastogi, Alison Thompson and Jeffery T. Davis
DOI: 10.1039/C4OB01399A, Paper

Catalytic amide allylation of α-ketoesters: extremely high enantioselective synthesis of ester functionalised α-methylene-γ-butyrolactones
Masaki Takahashi, Yusuke Murata, Masahiro Ishida, Fumitoshi Yagishita, Masami Sakamoto, Tetsuya Sengoku and Hidemi Yoda
DOI: 10.1039/C4OB01508H, Communication

Recent developments in transition metal-catalysed spiroketalisation
Rachelle Quach, Daniel F. Chorley and Margaret A. Brimble
DOI: 10.1039/C4OB01325E, Perspective

Non-isoprenoid polyene natural products – structures and synthetic strategies
Katrina S. Madden, Fathia A. Mosa and Andrew Whiting
DOI: 10.1039/C4OB01337A, Review Article

A Lewis acid-mediated conformational switch
Peter C. Knipe, Hannah Lingard, Ian M. Jones, Sam Thompson and Andrew D. Hamilton
DOI: 10.1039/C4OB01556H, Paper

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RSC Organic Division Poster Symposium 2014 one month left to submit

03 Sep 2014

Calling all final year organic chemistry PhD students

There is only one month left to submit your abstract for the RSC Organic Division’s poster symposium, headline sponsored by F. Hoffmann-La Roche, Ltd.

When & where?

The symposium will take place at The Royal Society of Chemistry, Burlington House, London on Monday 01 December 2014 and offers you the chance to showcase your research to your peers, leading academics and industrial chemists.

Prizes

There will be a first prize of £500, two runner-up prizes of £250, and a “selected by Industry Prize” also of £500.

Closing date for submissions is Wednesday 01 October 2014.

For more information and to submit your abstract go to http://rsc.li/organic-poster

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Myriad Multiplicity in Nitroenamine Multicomponent Methodology

28 Aug 2014

Not many molecules can claim to be both a Michael donor and Michael acceptor while containing a good leaving group as is the case with nitroketene-N,S-acetals like N-methyl-S-methyl nitroethylene (NMSM), broadly categorized as nitroenamines.

As a double actor in the pseudo three-component reaction investigated by Rao and Parthiban, moieties of NMSM react three times in two roles: twice as a nucleophile and once as an electrophile. The other components in the same pot included the aromatic aldehyde and catalytic 2-aminopyridine.

The methodology generates an alternate route from the classic Hantzsch reaction to the 1,4-dihydropyridine (DHP) platform with a broader scope and purification by recrystallization. Advantageously, 1,4-DHPs are calcium channel blockers and hydride sources for reduction.

The functionally-rich NMSM component conveniently diversifies DHP which could lead to more potent medicinal applications or pesticides.

The two inherent diversity points on the platform arose from the aldehyde and amine precursors. Additional diversity from amine substitution of the built-in sulfide leaving group created a total of 29 unique 1,4-DHP possibilities.

Specifically, they synthesized a neonictinoid insecticide analogue to the popular nitenpyram compound to constrain the alkene to the cis-isomer with muted toxicity to mammals.

Overall, leveraging an electronically versatile synthon like NMSM in a multicomponent reaction leads to enhanced diversity for analoging with myriad compounds that could perform better than those currently available.

To find out more see:

One-pot pseudo three-component reaction of nitroketene-N,S-acetals and aldehydes for synthesis of highly functionalized hexa-substituted 1,4-dihydropyridines
H. Surya Prakash Rao and A. Parthiban
DOI: 10.1039/c4ob00628c

Jennifer Lee is currently a Ph.D. candidate in Dr. George Kraus’ organic chemistry lab at Iowa State University. Her research focuses on designing methodologies to transform carbohydrate-derived biomass into biorenewable commodity and specialty chemicals. The creation of a versatile platform technology led to diverse and industrially-relevant aromatic compounds to work toward a more sustainable future.

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14th Anglo-Italian Meeting on Heterocyclic Chemistry

17 Jul 2014

The 14th Anglo-Italian Meeting on Heterocyclic Chemistry, organised by the Heterocyclic & Synthesis Group in collaboration with the Italian Chemical Society, recently took place.

It was an excellent meeting, held at Cumberland Lodge in Windsor Great Park, with around 50 participants, equally split between the two countries. There were some excellent lectures, including plenaries from:

Professor Stephen Clark (University of Glasgow)

Professor Sabine Flitsch (University of Manchester)

Dr King Kuok (Mimi) Hii (Imperial College London)

Professor Emanuela Licandro (University of Milan)

Professor Andrea Pace (University of Palermo)

Professor Claudio Trombini (University of Bologna)

Our congratulations go to Susan Lepri from University of Perugia who won our poster prize.

Susan receiving her prize from Professor Chris Willis (Heterocyclic Group) and Professor Giuseppe Musumarra (Italian Chemical Society)

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RSC Organic Division Poster Symposium 2014

04 Jul 2014

RSC Organic Division Poster Symposium 2014, headline sponsored by F. Hoffmann-La Roche, Ltd.

The poster symposium, for final year organic chemistry PhD students, will take place at The Royal Society of Chemistry, Burlington House, London on Monday 01 December 2014.

The symposium offers final year PhD students a chance to showcase their research to their peers, leading academics and industrial chemists, and is open to all branches of organic chemistry. The symposium has a tradition of being the most competitive and highly regarded organic chemistry symposium for PhD students in the UK and ROI and we would like to thank F. Hoffmann-La Roche, Ltd. for their generous support of the event.

There will be a first prize of £500, two runner-up prizes of £250, and a “selected by Industry Prize”. Industrial delegates will make this selection by considering the research’s potential for application in an industrial context; the winner will also receive a prize of £500.

Closing date for submissions is Wednesday 01 October 2014.
For more information and to submit your abstract go to http://rsc.li/organic-poster

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When a Spectator is not Just a Spectator in Iodonium Salts

30 Jun 2014

Advances in hypervalent iodine are flourishing¹ from the classic non-toxic Dess-Martin periodinane oxidation to synthetic reagents for elaborate natural products². New types of both iodine(III) and iodine(V) compounds are constantly being discovered for ever increasing applications.

Iodonium salts, classified as iodine(III) compounds, are notoriously electrophilic. Those with two carbon ligands like alkynyl(aryl)iodonium salts react with a nucleophile which couples with the alkyne. Overall, the reaction seemingly pieces together two nucleophilic entities.

The remaining aryl iodide in the balanced equation seems to be a “spectator” since it is absent in the product, but in this recent (open access) paper Hamnett and Moran sought to investigate whether that is truly the case.

They improved the preparation of alkynyl(aryl)iodonium tosylates and systematically applied them to two model reactions, finding that the 2-anisyl ligand provided the highest yields.

It significantly out-performed the 3-anisyl derivative, suggesting that the key to success is the inherent stability of the 2-anisyl iodonium salt with the methoxy group ideally situated for coordination to the iodine.

Discovering the effectiveness of the 2-anisyl ligand in iodonium salts could have implications for more efficient transformations involving hypervalent iodine. More broadly, the work shows the importance of optimizing reactions across all variables and highlighting that spectators may not always be simple bystanders.

To find out more see:

Improving alkynyl(aryl)iodonium salts: 2-anisyl as a superior aryl group
David J. Hamnett and Wesley J. Moran
DOI: 10.1039/C4OB00556B

1. M. S. Yusubov, A. V. Maskaev and V. V. Zhdankin, ARKIVOC, 2011, i, 370–409.
2. D. J. Wardrop and J. Fritz, Org. Lett., 2006, 8, 3659–3662.

Posted on behalf of Jennifer Lee, guest web writer for Organic & Biomolecular Chemistry

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