4. State of the Art and Outlook

The biotransformations described in this book demonstrate that this area is in an active state of development and that enzymes have attained an important position in contemporary organic synthesis [1–3]. The increased interest of synthetic chemists in the biotransformation of nonnatural compounds has spurred the commercial availability of enzymes in various forms and grades of purity [4]. To date, almost 10% of all papers published in the area of synthetic organic chemistry contain elements of biotransformations [5] and >130 industrial-scale processes are documented worldwide [6–17]. As shown in Fig. 4.1 the frequency of use of a particular biocatalyst is not evenly distributed among the various types of enzymes and it is obvious that the more ‘simple’ hydrolytic reactions are dominant.