Enzymes in Domino Reactions

Over the years of evolution, Nature has developed enzymes which are able to catalyze a multitude of different transformations with amazing enhancements in rate [1]. Moreover, these enzyme proteins show a high specificity in most cases, allowing the enantioselective formation of chiral compounds. Therefore, it is not surprising that they have been used for decades as biocatalysts in the chemical synthesis in a flask. Besides their synthetic advantages, enzymes are also beneficial from an economical - and especially ecological - point of view, as they stand for renewable resources and biocompatible reaction conditions in most cases, which corresponds with the conception of Green Chemistry [2]. 

Nature, however, has performed more than simple stepwise transformations using a combination of enzymes in so-called multienzyme complexes, it performs multistep synthetic processes. A well-known example in this context is the biosynthesis of fatty acids. Thus, Nature can be quoted as the inventor of domino reactions. Usually, as has been described earlier in this book, domino processes are initiated by the application of an organic or inorganic reagent, or by thermal or photochemical treatment. The use of enzymes in a flask for initiating a domino reaction is a rather new development. One of the first examples for this type of reaction dates back to 1981 [3], although it should be noted that in 1976 a bio-triggered domino reaction was observed as an undesired side reaction by serendipity [4]. 

In recent years, due to their increased availability, enzymes have been used in the development of domino reactions. This interesting field has recently been summarized by Faber and coworkers in an excellent review [5]. In this chapter, the different types of biocatalyzed domino reactions are discussed and classified (Table 8.1). 

Domino Reactions in Organic Synthesis. Lutz F. Tietze, Gordon Brasche, and Kersten M. Gericke Copyright 2006 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 3-527-29060-5 

Enzymatic trigger reaction Effect of trigger reaction Domino process 

Domino Reactions in Organic Synthesis. Lutz F. Tietze, Gordon Brasche, and Kersten M. Gericke 

Copyright 2006 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 3-527-29060-5 

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