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Why does the management of impurities scare people?

A recent survey suggested that out of all CMC topics the one at the forefront of many people’s minds and concerns is that of impurity control.  Why might that be the case? After all there is a strong framework provided by ICH in the form of ICH Q3A / Q3B (Impurities in drug substance and

Development and Scale Up of a Miyauri Borylation Process Using Tetrahydroxydiboron

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

Suzuki-Miyaura Coupling of Heteroaryl Halides – Understanding the trends for Pharmaceutically-Important Classes

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

Suzuki-Miyaura Cross-Coupling of Amides and Esters

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

Continuous Photo-Oxidation in a Vortex reactor

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

Green and Sustainable Solvents in Chemical Processes

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

Borrowing Hydrogen – a New Review

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