A Catalyst That Multitasks To Make Complex Molecules Organic Synthesis: Method leads to complex, biologically relevant molecules on gram scale

A copper catalyst guides this multicomponent reaction. 

A new synthetic strategy that relies on a multitasking copper catalyst allows chemists to construct useful molecules faster and with higher yield. Experts say it promises to fast-track complicated syntheses.

Fewer steps in a chemical synthesis often translate to a better yield of the final product. Chemists therefore prize so-called multicomponent reactions that orchestrate the assembly of multiple building blocks into a complex structure in a single stroke.

Boston College chemists Amir H. Hoveyda, Fanke Meng, and Kevin P. McGrath demonstrate their virtuosity in this regard by using an inexpensive copper catalyst that puts together complex molecules from an allene, a diboron reagent, and an allylic phosphate. The resulting products contain a stereogenic carbon center, a monosubstituted alkene, and a tough-to-synthesize Z-trisubstituted alkenylboron (Nature 2014, DOI: 10.1038/nature13735).

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http://cen.acs.org/articles/92/i38/Catalyst-Multitasks-Make-Complex-Molecules.html

A Catalyst Worthy of a Samurai

 

 http://www.chemistryviews.org/details/ezine/6244791/A_Catalyst_Worthy_of_a_Samurai.html

A Catalyst Worthy of a Samurai

New nickel catalyst to catalyze the cross-coupling reaction between carbonyl compounds and phenole derivatives
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Ketones Couple With Olefins In Alkylation Advance Organic Synthesis: Bifunctional catalyst weds reluctant partners

 

 

A bifunctional catalyst weds ketones to olefins in a by-product-free strategy. 

 

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 http://cen.acs.org/articles/92/i27/Ketones-Couple-Olefins-Alkylation-Advance.html

 

 

Ketones Couple With Olefins In Alkylation Advance

Organic Synthesis: Bifunctional catalyst weds reluctant partners.

Catalyst Under Stress

 
The oxidation of water to molecular oxygen is an important reaction in the frame of artificial photosynthesis, solar fuels, and a sustainable energy future. Iridium complexes have recently gained attention as effective precatalysts for this transformation. 

To gain deeper understanding of this process, Alceo Macchioni, University of Perugia, Italy, and colleagues aimed at intercepting the intermediates of the oxidative transformation of [Cp*Ir(bzpy)NO₃] (Cp* = pentamethylcyclopentadienyl, bzpy = 2-benzoylpyridine), which is a competent catalyst for water oxidation.
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http://www.chemistryviews.org/details/ezine/5838331/Catalyst_Under_Stress.html

Catalyst Calls The Shots - Organic Synthesis: Iron-based catalyst controls selectivity in C–H oxidations

 

Iron catalysts selectively oxidize different C–H bonds (yellow and green) in the same isoleucine substrate, reactions that would otherwise require independent synthetic routes from different starting materials.

http://cen.acs.org/articles/91/i40/Catalyst-Calls-Shots.html

Chemists have developed a new catalyst that accelerates oxidation of C–H bonds selectively in nonaromatic compounds such as terpenes, rather than relying on the inherent properties of the reactant molecules. The catalyst could boost the versatility with which organic compounds can be synthesized for drug discovery and other applications.

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http://cen.acs.org/articles/91/i40/Catalyst-Calls-Shots.html

Brevetoxin synthesis

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Anthony crasto brevetoxin synthesis from ANTHONY MELVIN CRASTO Ph.D

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

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

Novel uses of nanoparticle catalytic systems

Novel uses of nanoparticle catalytic systems

Easily prepared and recoverable nanoparticles with a diameter of 10–40 nm, with a high surface area and stability may provide a catalytic system or the support for a catalyst.

http://www.sciencereviews2000.co.uk/blog/view/journal-of-chemical-research/58/novel-uses-of-nanoparticle-catalytic-systems/676

Chemistry Living and Systems: 123.101 Lecture 1

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Chemistry Living and Systems: 123.101 Lecture 1 from Gareth Rowlands

Turning carbon dioxide into something useful -Carbon dioxide reduced to formate by iridium pincer catalyst

http://www.rsc.org/chemistryworld/2013/07/iridium-catalyst-carbon-dioxide-reduction-formate

New research shows that a water-soluble catalyst developed by scientists in the US can electrocatalytically transform carbon dioxide into a useful chemical feedstock.
The global demand for fuel is rising, as are carbon dioxide levels in the atmosphere. Recent studies have attempted to address the global carbon imbalance by exploring ways to recycle carbon dioxide into liquid fuels. Formate, the anion of formic acid, is an intermediate of carbon dioxide reduction and can be used as a fuel in formic acid fuel cells. However, the selective production of formate, without using organic solvents, is challenging. Water, being inexpensive and environmentally-friendly, is obviously preferred over organic solvents as a reaction medium. On the other hand, the reduction of carbon dioxide in water is complicated by the reduction of water to hydrogen being a more kinetically favourable process.
 http://www.rsc.org/chemistryworld/2013/07/iridium-catalyst-carbon-dioxide-reduction-formate

Catalyst duo exerts powerful stereocontrol

The dual catalyst enables selective access to the required stereoisomer © Science/AAAS

Chemists from the Swiss Federal Institute of Technology, ETH Zurich, have teamed chiral catalysts in pairs to selectively drive a reaction towards desired stereoisomeric products with high selectivity. Each catalyst activates one reagent and controls its substituent arrangement as it bonds to the other to form two neighbouring chiral centres. ‘We have shown that it is possible to develop fully stereodivergent reaction processes,’ says Erick Carreira, who led the work. ‘We expect that additional reactions displaying full stereodivergency will be identified.’

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http://www.rsc.org/chemistryworld/2013/05/catalyst-duo-powerful-stereocontrol-diastereomer

References

S Krautwald et al, Science, 2013, DOI: 10.1126/science.1237068