N-Methylmorpholine N-oxide (NMO) is commercially available in bulk as a 50% aqueous solution. Anhydrous material is available but only in small quantities.
A NEW Book written by L A (Bert) Hulshof
Scientific Update LLP (SU) have published a new book which falls into the theme expressed on many SU courses and conferences, namely trying to bring chemists and chemical engineers closer together to help with transfer of processes from Lab to Plant.
The book, “Right First Time in Fine Chemical Process Scale Up” has been written by Dr Bert Hulshof, formerly of DSM and the University of Eindhoven in the Netherlands, who suggests that the key to success is to avoid scale-up problems.
Understanding mechanisms underpins much of what we do in organic chemistry, so I have always been interested in looking at mechanisms and enjoy looking at the possibilities when I come across something unusual or new to me.
This paper caught my as a nice piece of chemistry and set alongside the many papers with new chemistry I thought it interesting to see some more classical chemistry getting re-visited to generate chemistry of industrial utility.
Ever since 1997 when I was developing a process using aqueous sodium bicarbonate to mediate the mesylation of an amine and got impurities generated from the incorporation of carbon dioxide I have been intrigued by chemistry that uses carbon dioxide as a reactant.
We are all quite familiar with enzyme-mediated kinetic resolution of alcohols and of course have become accustomed to the extremely high enantiomeric excesses (ee’s) that can be achieved.
As a process chemist I like to look for unexpected chemistry and also chemistry which, under the wrong circumstances could result in reaction side-products and/or impurities. As a result I look out for reactions involving solvents, or at least ‘reactants’ typically regarded as ‘solvents’ as illustrated by these two cases.
Triggered by the work of Kriche and Williams I have found an interest in hydrogen-transfer reactions where the intermediate is trapped by a nucleophile. The paper I Ryu et al, (Org Lett, 2012, 14 (18), 4703) describes the formation of a C-C bond between a ketone and a primary alcohol catalysed by a ruthenium hydride.
Why not join us for free workshops at these events...
New Ligand for More Efficient Asymmetric Oxidation of Sulfides to Sulfoxides
Asymmetric oxidation of sulfoxides is an important industrial process, being used in the last step of manufacture of the blockbuster drug esomeprazole (Nexium) and other “prazoles” (see H-J. Federsel and M. Larsson (AstraZeneca) in Asymmetric Catalysis on Industrial Scale, ed H.U. Blaser and E. Schmidt, Wiley-VCH, 2004, pp 413-436). The AZ process derives from earlier work done by Kagan in 1984 in which the hydroperoxide oxidant achieves the desired enantioselectivity in the presence of titanium isopropoxide, diethyl tartrate (DET) and water ( the last three in a 1:2:1 ratio). In a similar system devised by Modena, which also dates from 1984, titanium isopropoxide, DET and isopropyl alcohol are used but in a 4:1:4 ratio.
Two recent papers from Molander’s group have described new reagents for the Pd catalysed borylation of aromatics as an alternative to the use of bispinacolatodiboron (B2Pin2). In the first paper the reagent used is bis-boronic acid which is an air-stable crystalline solid:
Here’s something from a Chemistry Olympiad challenge to play with over a mug of coffee or tea!
Two recent papers from the group of Percec at the University of Philadelphia have looked at the efficiency of nickel catalysed Szuki-Miyaura couplings1,2.
I attended this SCI conference on 24-25 September and was treated to a series of excellent lectures, with the majority being academic speakers discussing various aspects of catalysed reactions, since their brief was to present on their work which had involved collaboration with industry.
Last year I commented on a report by B Luy Angew Chem, Int ed 2011, 50, (2), 354 in which he discusses the prospects of portable proton NMR. In this 'highlights' paper the author comments on the current status, remarking that at least one group has designed and built a 30MHz machine wherein the magnet weighs about 3kg and the is about the size of a tea mug. Luy concluded that low-field high resolution NMR spectroscopy is advancing rapidly and a prototype 20MHz tabletop NMR spectrometer has been built.