Catalysis Green chemistry

Keywords Bismuth(IH) salts Catalysis Green chemistry Lewis acidity Moisture tolerance Non-toxicity Organic transformations... 

Ask the average man on the street for an example of catalysis, and you will most likely hear about the thing on the exhaust pipe that reduces engine emissions . As we shall see, the remarkable story of the catalytic converter is not only an excellent example of catalysis, but also highlights the connection between heterogeneous catalysis, green chemistry, and sustainable development. 

Control of residual metal content is outlined in ICH Q3D. It is noteworthy that the metals currently most useful for chemical catalysis (Green Chemistry Principle 9), e.g. palladium and some platinum group metals (Rh, Ru, Ir), are subject to tight restriction because of known toxicity, or the assumption of near neighbour similarity in the absence of data. All four metals have an oral concentration limit of 10 ppm, reducing to 1 ppm via parenteral administration and 0.1 ppm via inhalation. Typically, delivery of API with low residual metal content can require additional processing and careful analysis to determine levels. Some of the more abundant metals suggested... 

B. S. Green, Y. Ashani, and D. Chipman, eds.. Chemical Approaches to Understanding En me Catalysis Biomimetic Chemistry and Transition State Analogs, Elsevier, Amsterdam, 1982. 

Enzyme-mediated oxidation reactions offer highly diverse options for the modification of existing functional groups as well as for the introduction of novel function in chiral catalysis. Biooxidations often enable us to obtain complementary solutions to metal-assisted transformations and organocatalysis and are considered one of the important strategies of green chemistry . 

In the 20 years since the Brunddand report, great developments have taken place in industries toward sustainable practices. As a case in point, the problem of acid rain, an issue of concern in 1987, has improved to a large extent, thanks to catalytic pollution abatement both in stationary and automotive emissions. Catalysis for Green Chemistry and Engineering will continue to have a cracial role in improving the environmental performance of industry [25-27]. Nowadays, catalytic procedures are often implemented according to the green chemistry... 

Biocatalysis refers to catalysis by enzymes. The enzyme may be introduced into the reaction in a purified isolated form or as a whole-cell micro-organism. Enzymes are highly complex proteins, typically made up of 100 to 400 amino acid units. The catalytic properties of an enzyme depend on the actual sequence of amino acids, which also determines its three-dimensional structure. In this respect the location of cysteine groups is particularly important since these form stable disulfide linkages, which hold the structure in place. This three-dimensional structure, whilst not directly involved in the catalysis, plays an important role by holding the active site or sites on the enzyme in the correct orientation to act as a catalyst. Some important aspects of enzyme catalysis, relevant to green chemistry, are summarized in Table 4.3. 

Table 4.3 Aspects of enzyme catalysis relevant to green chemistry...

Born in Oban, Argyll, in 1960, Duncan Macquarrie studied Pure and Applied Chemistry at the University of Strathclyde, graduating with a first class degree in 1982 and a PhD in 1985. He then moved to York, where he carried out research in Phase Transfer Catalysis. He subsequently spent time in industry, where he worked in the UK and abroad, mostly in synthetic chemistry, but always with an interest in method development and catalysis. He returned to York in 1995 to take up a Royal Society University Research Fellowship, and has developed a range of novel catalysts for green chemistry. He is Associate Editor of Green Chemistry, and a National Member of Council with the Royal Society of Chemistry. 

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