Read the complete study for free for 4 weeks!
A new approach to inhibit human β-tryptase by protein surface binding of four-armed peptide ligands with two different sets of arms
Qian-Qian Jiang, Lina Bartsch, Wilhelm Sicking, Peter R. Wich, Dominik Heider, Daniel Hoffmann and Carsten Schmuck
DOI: 10.1039/C3OB27302D
Over the past few decades a lot of interest has been given to macrocycles with a twisted structure that has a preferred direction and show an optical chirality due to their possible uses in many areas such as in materials for chiral recognition.
In this HOT paper Eiji Yashima and colleagues from Nagoya University report the design and synthesis of three helically twisted [1 + 1]macrocycles, whose chirality can be controlled by acid–base interactions and zinc coordination.
Yashima et al. connect the twisted [1 + 1]macrocycles using via o-, m-, and p-linkages and use chiral amidinium–carboxylate salt bridges as a versatile structural motif to control the twisting motion of the macrocycles.
Find out all of the details of this study by downloading this paper. It’s free to access for 4 weeks.
Synthesis of helically twisted [1 + 1]macrocycles assisted by amidinium–carboxylate salt bridges and control of their chiroptical properties
Yuji Nakatani, Yoshio Furusho and Eiji Yashima
DOI: 10.1039/C2OB27054D
The deadline for submitting poster abstracts for the 23rd International Symposium: Synthesis in Organic Chemistry is fast approaching – 11 March 2013.
The Synthesis in Organic Chemistry conference is the flagship event of the RSC’s Organic Division. This conference will provide an international showcase for the core area of organic chemistry – synthesis – covering all aspects of contemporary organic synthesis and providing a forum for the ever more exciting methodologies and strategies that continue to emerge.
Don’t miss out – reserve your poster presentation space for a chance to showcase your own work, and register early to take advantage of the £50 saving on the standard fee.
Remember too that there are a limited number of bursaries on offer for students and younger members of the RSC in the early stages of their career – worth £150.
Make sure you take the opportunity to join us to hear outstanding speakers across the many themes of the symposium in an extremely stimulating programme of plenary and keynote lectures.
Check out the event website to find out more – http://rsc.li/os23
Issue 9 of Organic & Biomolecular Chemistry is out now. Why not take a break, put your feet up with a can of your favourite drink and browse all the great content.
This week’s front cover highlights the work of Simon E. Lewis and colleagues at the University of Bath who demonstrate the applicability of Baddeley’s “aliphatic Friedel–Crafts” procedure to a range of saturated hydrocarbon substrates, and discuss its mechanism with the aid of DFT modelling data.
Aliphatic C–H activation with aluminium trichloride–acetyl chloride: expanding the scope of the Baddeley reaction for the functionalisation of saturated hydrocarbons
Catherine L. Lyall, Mario Uosis-Martin, John P. Lowe, Mary F. Mahon, G. Dan Pantoş and Simon E. Lewis
DOI: 10.1039/C2OB26765A
On the inside front cover is the work of Lei Zhou and co-workers at Sun Yat-Sen University who describe a general synthesis of 2-substituted benzofurans and indoles through a CuBr-catalyzed coupling–allenylation–cyclization sequence.
Benzofuran and indole synthesis via Cu(I)-catalyzed coupling of N-tosylhydrazone and o-hydroxy or o-amino phenylacetylene
Tiebo Xiao, Xichang Dong and Lei Zhou
DOI: 10.1039/C2OB26867A
Both articles can be read for free for the next 6 weeks!
| Inside this issue: 1 Perspective, 6 Communications, 12 Papers.
HOT Communication: An organocatalytic asymmetric double Michael cascade reaction of unsaturated ketones and unsaturated pyrazolones: highly efficient synthesis of spiropyrazolone derivatives HOT Communication: A sterically demanding organo-superbase avoids decomposition of a naked trifluoromethyl carbanion directly generated from fluoroform |
Zhao et al. use techniques including dynamic light scattering, scanning electron microscopy and transmission electron microscopy to permit the detailed examination of these elegant supramolecular assemblies.
Acetone mixtures of the two components produce small building blocks at concentrations of 0.5 mM, with expanding aggregates rolling into hollow nanospheres when concentrations approach 1 mM. Beyond this concentration large flat layers are created, which stack at concentrations in excess of 2 mM. In essence the system demonstrates a reversible multidimensional transformation from 0D to 3D, and is an example of controlled dynamic self-assembly. This represents a novel method for developing new functional materials with a switchable morphology control.
| Host–guest complexation driven dynamic supramolecular self-assembly Huacheng Zhang, Kim Truc Nguyen, Xing Ma, Hong Yan, Junfei Guo, Liangliang Zhu and Yanli Zhao DOI: 10.1039/C2OB27340C Free to access for 4 weeks |
Published on behalf of Steve Moore, Organic & Biomolecular Chemistry web science writer.
Issue 8 of Organic & Biomolecular Chemistry has landed and has brought clouds of chemistry along with it.
The front cover highlights the work of Goran Angelovski and colleagues who report the preparation and characterization of two novel macrocyclic gadolinium pH sensitive smart contrast agents appended with a phosphonate pendant arm and either an aliphatic or aromatic linker.
Synthesis and characterization of pH-sensitive, biotinylated MRI contrast agents and their conjugates with avidin
Sandip M. Vibhute, Jörn Engelmann, Tatjana Verbić, Martin E. Maier, Nikos K. Logothetis and Goran Angelovski
DOI: 10.1039/C2OB26555A
On the inside cover is the HOT article by Maggie He and Jeffrey W. Bode, which we have previously blogged about, highlighting their efforts in isolating a single bullvalene structure from a dynamic mixture of 852 isomers and their computational & network mapping investigations.
E pluribus unum: isolation, structure determination, network analysis and DFT studies of a single metastable structure from a shapeshifting mixture of 852 bullvalene structural isomers
Maggie He and Jeffrey W. Bode
DOI: 10.1039/C2OB26954F
Both of these cover articles are free to access for 6 weeks.
Also in this week’s issue: 1 Emerging area review, 3 Communications & 14 Articles.
Researchers in China have developed a simple and effective way to construct spiropyrazolones, stereochemically complex and challenging structural motifs found in many biologically active molecules.
| An organocatalytic asymmetric double Michael cascade reaction of unsaturated ketones and unsaturated pyrazolones: highly efficient synthesis of spiropyrazolone derivatives Jinyan Liang, Qiao Chen, Luping Liu, Xianxing Jiang and Rui Wang DOI: 10.1039/C2OB27095A |
3-Pyrazolones are privileged structures and molecules that contain them have been found to possess a huge range of useful biological effects such as antibiotic and anti-tumour properties. In addition to their marked medicinal potential, they have also found use as dyes and anti-corrosives.
For these reasons, methods for the construction of pyrazolone derivatives have attracted intense interest from organic chemists in recent years. The synthesis of optically active pyrazolones, including spiropyrazolones, is particularly challenging with only a handful of syntheses reported in the current literature.
Professor Rui Wang, of the State Key Laboratory of Applied Organic Chemistry, Lanzhou University in China and his research group have been looking into new ways to make spirocyclic compounds, using organocatalytic cascade reactions.
In their latest HOT PAPER, they turn their attention to the construction of spiropyrazolones. A very elegant organocatalytic double Michael cascade reaction between unsaturated ketones and unsaturated pyrazolones yields the desired spiropyrazolone core structure in excellent diastereo- and enantioselectivities.
This reaction provides rapid entry into stereochemically complex spiropyrazolone derivatives and will no doubt prove useful in the manufacture of future medicines and materials.
Published on behalf of Annabella Newton, Organic & Biomolecular Chemistry web science writer.
Welcome to this week’s issue of Organic & Biomolecular Chemistry!
On the front cover:
M. Cepeda and co-workers explore the solution phase behaviour of β-cyclodextrin/alkyltrimethylammonium bromide mixtures, varying the surfactant alkyl chain length from hexyl (C6) to octadecyl (C18).
Competition between surfactant micellization and complexation by cyclodextrin
M. Cepeda, R. Daviña, L. García-Río, M. Parajó, P. Rodríguez-Dafonte and M. Pessêgo
DOI: 10.1039/C2OB26318A
On the inside cover:
Jasmin Mecinović and colleagues describe how hydroxylamine acts as an oxygen nucleophile in the substitution reaction with benzothiazole-2-sulfonamides in aqueous media.
Hydroxylamine as an oxygen nucleophile: substitution of sulfonamide by a hydroxyl group in benzothiazole-2-sulfonamides
Jos J. A. G. Kamps, Roman Belle and Jasmin Mecinović
DOI: 10.1039/C2OB26929E
Don’t forget, both of these cover articles are free to access for the next 6 weeks!
Get your hands on the rest of the great content in this issue HERE, and why not have a look at some of the latest published articles not yet in an issue.
The flow-based route required minimal manual intervention and was achieved despite poor solubility of many reaction components
UK chemists have used a combination of flow chemistry methods with solid-supported scavengers and reagents to synthesise the active pharmaceutical ingredient, imatinib, of the anticancer drug Gleevec. The method avoids the need for any manual handling of intermediates and allows the drug to be synthesised in high purity in less than a day.
Gleevec, developed by Novartis, is a tyrosine kinase inhibitor used for the treatment of chronic myeloid leukaemia and gastrointestinal stromal tumours. The drug molecule represents a particularly challenging target for flow chemistry because of the low solubility of many of the reaction components required for its synthesis. The team devised a new synthesis route that prevents the equipment blockages from product precipitation and avoids many of the labour and time intensive practices of traditional batch-based preparation.
The work proved to be a challenge. Steve Ley, at the University of Cambridge, who led the team, says that along the way, they ‘met some considerable obstacles and dead ends’. He remarks that ‘in order to overcome the need to change solvents between some of the reaction stages, we had to invent a new in-line evaporator, which served us well in this and in later synthesis studies’.
Unlike the conventional industrial synthesis of Gleevec, this newly developed route couples molecular fragments in a modular approach. Thomas Wirth, who works on microreactor technology at Cardiff University, UK, remarks that ‘although not designed to compete with the industrial synthesis, the modular approach allows an easy variation of building blocks for the efficient and rapid generation of Gleevec analogues for screening purposes’.
A total of nine analogues were synthesised using the final equipment set-up, which were then screened for anticancer activity. The findings revealed that the piperazine group in the drug molecule plays a role in receptor binding, rather than simply acting as a solubilising group as previously thought.
Ley’s team is now working to combine the synthesis and screening to provide information on products rapidly, as well as extending their approach to new functional materials.
Read the Organic & Biomolecular Chemistry paper, for free for 4 weeks here:
An expeditious synthesis of imatinib and analogues utilising flow chemistry methods
Mark D. Hopkin, Ian R. Baxendale and Steven V. Ley
Org. Biomol. Chem.
DOI: 10.1039/C2OB27002A
Story first published in Chemistry World.
This week in Organic & Biomolecular Chemistry we are bringing you: 1 Emerging Area review, 4 Communications and 18 articles full of interesting chemistry. Visit the issue and get it all!
On the front cover:
Andreea R. Schmitzer and coworkers present the first example of a benzimidazolium-based artificial transmembrane chloride transporter and a synthetic calcium ionophore that can regulate intracellular calcium concentrations in bacteria.
Benzimidazolium-based synthetic chloride and calcium transporters in bacterial membranes
Claude-Rosny Elie, Audrey Hébert, Mathieu Charbonneau, Adam Haiun and Andreea R. Schmitzer
DOI: 10.1039/C2OB26966J
On the inside cover:
Noriho Kamiya and colleagues at Kyushu University assess how the spatial arrangement of the avidin–biotin interaction between protein building blocks affects the formation of a protein supramolecular complex.
Protein supramolecular complex formation by site-specific avidin–biotin interactions
Yutaro Mori, Rie Wakabayashi, Masahiro Goto and Noriho Kamiya
DOI: 10.1039/C2OB26625C
![Synthesis of helically twisted [1 + 1]macrocycles assisted by amidinium–carboxylate salt bridges and control of their chiroptical properties](http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=C2OB27054D)