The biocatalytic repertoire of natural biaryl formation.

The catalytic and selective construction of carbon-carbon bonds for the generation of complex molecules is one of the most important tasks in organic chemistry. This was clearly highlighted by the 2010 Nobel Prize in Chemistry, which was awarded for the development of Pd-catalyzed cross-coupling reactions. The underlying concept of cross-linking building blocks to generate molecular complexity can also be widely found in natural product biosynthesis. Impressive examples for such natural cross-coupling reactions are biosynthetic processes for the assembly of biaryl moieties in natural products--highly efficient enzymatic reactions that often achieve synthetically yet unmatched selectivities. This Minireview highlights selected examples that showcase these fascinating biotransformations.