End-to-End Automated Synthesis of C(sp³)‑Enriched Drug-like Molecules via Negishi Coupling and Novel, Automated Liquid–Liquid Extraction

Herein, we report an end-to-end process including synthesis, work-up, purification, and post-purification with minimal human intervention using Negishi coupling as a key transformation to increase Fsp³ in bioactive molecules. The main advantages of this protocol are twofold. First, the automated sequential generation of organozinc reagents from readily available alkyl halides offers a large diversity of alkyl groups to functionalize (hetero)­aryl halide scaffolds via Pd-catalyzed Negishi coupling in continuous flow. Second, a fully automated liquid–liquid extraction has been developed and successfully applied for unattended operations. The workflow was completed with mass-triggered preparative high-performance liquid chromatography HPLC, providing an efficient production line of compounds with enriched sp³ character and better drug-like properties. The modular nature allows a smooth adaptation to a wide variety of synthetic methods and protocols and makes it applicable to any medchem laboratory.