One-Pot Approach to α,β-Unsaturated Carboxylic Acids

 

One-Pot Approach to α,β-Unsaturated Carboxylic Acids

Carboxylation of alkynes with carbon dioxide in a one-pot approach could become a practical route to unsaturated carboxylic acids
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Concise Total Synthesis of a Newly Discovered Alkaloid

 

A concise synthesis of a novel alkaloid natural product with the pyrroloindoloquinazoline skeleton has been devised
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Nano-Technoloogy Makes Medicine Greener

The ultra small nanoreactors have walls made of lipids. During their fusion events volumes of one billionth of a billionth of a liter were transferred between nanoreactors allowing their cargos to mix and react chemically. We typically carried out a million of individual chemical reactions per cm2 in not more than a few minutes. (Credit: Image courtesy of University of Copenhagen)http://www.sciencedaily.com/releases/2011/11/111103132357.htm

 Researchers at the University of Copenhagen are behind the development of a new method that will make it possible to develop drugs faster and greener. Their work promises cheaper medicine for consumers.

Over the last 5 years the Bionano Group at the Nano-Science Center and the Department of Neuroscience and Pharmacology at the University of Copenhagen has been working hard to characterise and test how molecules react, combine together and form larger molecules, which can be used in the development of new medicine.http://www.sciencedaily.com/releases/2011/11/111103132357.htm

The first total synthesis of fuscain

First total synthesis of fuscain

Fuscain is a new furanolactam isolated from the sponge Phacellis fusca from the South China Sea. Furan analogues isolated from marine organisms have valuable medicinal properties. The first total synthesis of fuscain is reported in Journal of Chemical Research December issue. The key step in the synthesis is the formation of seven-membered lactam by acylation of a furan ring using the mild Lewis acid CuSO₄•5H₂O.

Fuscain, a new furanolactam which was originally isolated from the sponge Phacellis fusca collected in South China Sea, showed a moderate cytotoxicity toward P388 and L1210 cell lines. The same sponge yielded three pyrrololactam alkaloids: saldisin, 2-bromoaldisin and debromohymenialdisin.2 Recently, furan analogues isolated from marine organisms have shown anticancer,3–5 antibacterial,6 anticoagulant, antifungal, antimalarial,  antiplatelet, antituberculosis and antiviral activities11. Aldisin-based derivatives can be easily synthesised. However, it is still a challenge to synthesise fuscain. Hence the biological effects of fuscain and its derivatives on cell cycle progression and antitumour activities have rarely been reported. The synthetic route to fuscain is shown below.

The key step is an intramolecular Friedel–Crafts cyclisation to form the seven-membered ring. Various Lewis acids (polyphosphoric acid, POCl3, polyphosphoric acid–acetic acid, POCl3–P2O5, TFA or MSA) have been reported for Friedel– Crafts cyclisation.13,14. Initially, we selected PPA and P2O5 as catalysts but no product was obtained. Because of the structural difference between Alidisin and fuscain, the aromaticity of furan ring is less than a pyrrole ring, and a furan ring usually polymerised under acidic conditions, we selected a relatively mild Lewis acid CuSO4•5H2O to complete the intramolecular cyclisation to form fuscain.

Source: Journal of Chemical Research, Volume 36, Number 12, December 2012 , pp. 736-737(2)

doi: 10.3184/174751912X13528167435099

Yuan-wei Liang, Xiao-jian Liao, Chang-jun Wang, Jin-zhi Guo, Shuo Li and Shi-hai Xu*
Department of Chemistry, Jinan University, Guangzhou 510632, P. R. China

http://stl.publisher.ingentaconnect.com/content/stl/jcr/2012/00000036/00000012/art00016

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A Spontaneous Resolution

 

Chiral supramolecular fluorophores can be made by simple crystallization
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http://www.chemistryviews.org/details/ezine/1421575/A_Spontaneous_Resolution.html

Building nanographene by organic synthesis

Direct C-H coupling of pyrene makes nanographenes with defined shape and edge structures

Japanese scientists are making tiny fragments of graphene using direct
cross-coupling of C-H bonds to determine what effect size and edge geometry
have on the properties of carbon materials. By bolting together aromatic hydrocarbons, they can
build nanographene fragments with defined shapes in an attempt to relate geometry to performance.

Speaking at the RSC’s seventh International Symposium on Advancing the Chemical Sciences in Edinburgh, UK, Kenichiro Itami from Nagoya University explained .............read all at

http://www.rsc.org/chemistryworld/2012/06/building-nanographene-organic-synthesis

A new labdane diterpene from Rauvolfia tetraphylla Linn. (Apocynaceae)

A new labdane diterpene from Rauvolfia tetraphylla Linn. (Apocynaceae)

Rauvolfia tetraphylla Linn. (syn. R. canescens L., family: Apocynaceae) holds an important position in the Indian traditional system of medicine, and has other immense applications. This particular plant is regarded as a rich source of a wide variety of important alkaloid constituents such as reserpine, reserpiline, raujemidine, isoreserpiline, deserpidine, aricine, ajmaline, ajmalicine, yohimbines, serpentine, sarpagine, vellosimine and tetrphylline. However, there is no report on the terpenoid constituent from this plant, and we report the isolation from the air-dried stems and branches of R. tetraphylla and structural elucidation of a new labdane diterpene, 3-hydroxy-labda-8(17),13(14)-dien-12(15)-olide (1; Fig. 1) bearing  an unusual -lactone moiety.

Fig. 1 Structure of labdane diterpene

Goutam Brahmachari*, Lalan Ch. Mandal, Dilip Gorai, Avijit Mondal, Sajal Sarkar and Sasadhar Majhi

Doi: 10.3184/174751911X13220462651507

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http://www.sciencereviews2000.co.uk/blog/view/journal-of-chemical-research/58/a-new-labdane-diterpene-from-rauvolfia-tetraphylla-linn-apocynaceae/552