Enzyme-Initiated Domino-(Cascade)-Reaction

An impressive number of chemo-catalyzed cascade-reactions (especially those involving cyclizations) have been accomplished by using palladium [1-3]. Other types of typical cascade-reactions (although they have been denoted as 'tandem-reactions' in the respective publications) have been reviewed and classified according to their type of mechanism [4]. All of these reaction sequences were initiated by an organic or inorganic catalyst, or by thermal reactions. On the contrary, only few examples of cascade-reactions have been reported, where the initiation of the reaction cascade consisted of a biotransformation [5]. Taking advantage of the unparalleled diastereo- and enantio-specificity of enzymes, in many cases the reaction cascade was turned into an asymmetric fashion which furnished non-racemic product(s).