Continuous-Flow Synthesis of Cycloparaphenylene Building Blocks on a Large Scale.

The synthesis of [n]cycloparaphenylenes ([n]CPPs) and similar nanohoops is usually based on combining building blocks to a macrocyclic precursor, which is then aromatized in the final step. Access to those building blocks in large amounts will simplify the synthesis and studies of CPPs as novel functional materials for applications. Herein, we report a continuous-flow synthesis of key CPP building blocks by using versatile synthesis techniques such as electrochemical oxidation, lithiations and Suzuki cross-couplings in self-built reactors on up-to kilogram scale.