Biomimetic organocatalytic C-C-bond formations.

Mother Nature utilizes simple precursors to build up complex organic molecules efficiently. One important example is the C3 building block dihydroxyacetone phosphate, which is used in various enzyme-catalyzed reactions. Following this biosynthetic strategy the DHAP equivalent 'dioxanone' can be used in organocatalytic reactions to synthesize sugars, aminosugars, carbasugars, polyoxamic acids and sphingosines. In this respect, organocatalytic domino reactions can also be seen as biomimetic as they are reminiscent of tandem reactions that may occur during biosyntheses of complex natural products. In nature, the coenzyme thiamin (vitamin B1), a natural thiazolium salt, is used in biochemical nucleophilic acylations ('Umpolung'). The catalytic active species is a nucleophilic carbene. Mimicking this approach, organocatalytic carbene catalysis has emerged to an exceptionally fruitful research area, which is used in asymmetric C-C bond formations.