Enzymes are versatile catalysts in the laboratory and on an industrial scale. To broaden their applicability in the laboratory and to ensure their (re)use in manufacturing the stability of enzymes can often require improvement. Immobilisation can address the issue of enzymatic instability. Immobilisation can also help to enable the employment of enzymes in different solvents, at extremes of pH and temperature and exceptionally high substrate concentrations. At the same time substrate-specificity, enantioselectivity and reactivity can be modified. However, most often the molecular and physical–chemical bases of these phenomena have not been elucidated yet. This tutorial review focuses on the understanding of enzyme immobilisation.

The production of renewable chemicals is gaining attention over the past few years. The natural resources from which they can be derived in a sustainable way are most abundant in sugars, cellulose and hemicellulose. These highly functionalized molecules need to be de‐functionalized in order to be feedstocks for the chemical industry. A fundamentally different approach to chemistry thus becomes necessary, since the traditionally employed oil‐based chemicals normally lack functionality. This new chemical toolbox needs to be designed to guarantee the demands of future generations at a reasonable price. The surplus of functionality in sugars and glycerol consists of alcohol groups. To yield suitable renewable chemicals these natural products need to be defunctionalized by means of dehydroxylation. Here we review the possible approaches and evaluate them from a fundamental chemical aspect.

The many waves of biocatalysis have arisen to solve long-standing synthetic challenges. From industrially applied hydrolases to enzymes catalysing selective C–C-bond formation, biocatalysis enables new tools to access a plethora of compounds.

In this review the current state‐of‐the‐art of S‐adenosylmethionine (SAM)‐dependent methyltransferases and SAM are evaluated. Their structural classification and diversity is introduced and key mechanistic aspects presented which are then detailed further. Then, catalytic SAM as a target for drugs, and approaches to utilise SAM as a cofactor in synthesis are introduced with different supply and regeneration approaches evaluated. The use of SAM analogues are also described. Finally O‐, N‐, C‐ and S‐MTs, their synthetic applications and potential for compound diversification is given.

Biocatalysis is one of the most promising technologies for the sustainable synthesis of molecules for pharmaceutical, biotechnological and industrial purposes. From the gram to the ton scale, biocatalysis is employed with success. This is underpinned by the fact that the global enzyme market is predicted to increase from $7 billion to $10 billion by 2024. This review concentrates on showing the strong benefits that biocatalysis and the use of enzymes can provide to synthetic chemistry. Several examples of successful implementations of enzymes are discussed highlighting not only high-value pharmaceutical processes but also low-cost bulk products. Thus, biocatalytic methods make the chemistry more environmentally friendly and product specific.

During the last decades much attention has been paid, by both academia and industry, to the development of new solvents. The introduction of ILs, sc-fluids and solid–gas interphase reactions has definitely opened new perspectives. ILs have been introduced into organic chemistry to meet the increasing demand for clean technologies in industrial processes. However, the toxicology of ILs remains unclear and further studies are necessary to assess their sustainability. Use of supercritical fluids is already a mature technique and their power lies less in their number but more in the variety of characteristics that one sc-fluid can have depending on the pressure. Enzyme-catalysed reactions at the solid–gas interphase have undergone a rapid development, and this will definitely find a place in the production of high value added compounds, such as fragrances.