► Novel C–C bond formations from lyases, oxidoreductases and transferases reviewed. ► Highlights from lyases are the Stetter reaction, and the synthesis of N-heterocyclases and the first intermolecular Diels-Alderase. ► The highlight from oxidoreductases is the aerobic oxidative C–C coupling.
Carbon–carbon bond formation is the key transformation in organic synthesis to set up the carbon backbone of organic molecules. However, only a limited number of enzymatic C–C bond forming reactions have been applied in biocatalytic organic synthesis. Recently, further name reactions have been accomplished for the first time employing enzymes on a preparative scale, for instance the Stetter and Pictet–Spengler reaction or oxidative C–C bond formation. Furthermore, novel enzymatic C–C bond forming reactions have been identified like benzylation of aromatics, intermolecular Diels-Alder or reductive coupling of carbon monoxide.