Borrowing Hydrogen – a New Review
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| The concept of borrowing hydrogen (also known as Hydrogen auto-transfer) is a useful concept which combines transfer hydrogenation with other reactions to produce more complex molecules, exemplified by the alkylation of amines with alcohols and the reaction of benzyl alcohol with acetophenone to give 1,3 diphenylpropanone. For the process chemist these processes seem to be Read More | |
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Continuous Photo-Oxidation in a Vortex reactor
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| Photochemistry is an attractive synthetic method but has not been used widely in industry, except for one or two special processes. In batch processes, the efficiency of light usage is poor, partly owing to the reactors becoming fouled up in the region of the lamp and continuous processes should have more favourable characteristics. There has Read More | |
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Development and Scale Up of a Miyauri Borylation Process Using Tetrahydroxydiboron
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| One of the disadvantages of Miyaura borylation is that normally a diboron ester, such as bis(pinacolato)diboron, needs to be used and the resultant coupled ester has to be hydrolysed to its corresponding acid. This leads to poor atom efficiency and longer processing times. Separating the pinacol waste from desired products can sometimes be challenging. A Read More | |
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Green and Sustainable Solvents in Chemical Processes
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| The topic of green and sustainable solvents is of growing interest to industry, which recognizes the need to reduce solvent usage and to minimize the use of certain solvents of toxicological concern. This up-to-date review from the group of Hallett in the Chemical Engineering Dept at Imperial College, London has almost 500 references focusing on Read More | |
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Purge Factor Calculations – in ICH Quality Guidelines
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| ICH M7 provides greater flexibility to assess the risk posed by Mutagenic Impurities. This is described in section 8 – Control of the guideline and defined as a series of control options. Of these Option 4 permits an applicant to present an argument for control based on the physico-chemical properties of a mutagen and the Read More | |
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New Small-Scale Photoreactor
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| As someone who did his PhD on photochemistry, I have always been surprised at how little photochemistry is used in making new molecules, given the unusual transformations that photochemistry can enable. However, there has been a resurgence in the use of photochemistry in the last decade in academic laboratories. But the equipment had hardly changed Read More | |
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Suzuki-Miyaura Coupling of Heteroaryl Halides – Understanding the trends for Pharmaceutically-Important Classes
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| This perspective article, from workers at Imperial College London and Pfizer, Cambridge, reviews the literature on site-selectivity in S-M coupling reactions for a wide variety of heterocycles on a case-by-case basis. It is shown that experimental parameters can critically impact the dominant catalytic species in solution and its ability to undergo the site-selectivity determining oxidative Read More | |
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Suzuki-Miyaura Cross-Coupling of Amides and Esters
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| The Suzuki-Miyaura cross coupling reaction has been widely used in industry for C-C bond formation but has not successfully been applied to unactivated substrates such as amides and esters, in which the C-N and C-O bonds are cleaved. This recent report from scientists in Wroclaw (Poland), Beijing and New Jersey gets around the normally slow Read More | |
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