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

Abstract

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.

Fully Automated Flow Protocol for C(sp3)–C(sp3) Bond Formation from Tertiary Amides and Alkyl Halides

“…Results showed that all combinations produced the desired compounds in reasonable yield except when the organozinc derived from azetidine C was used where product was not detected, probably because of its lower nucleophilicity. Compounds 32A , 33A , 34A , 33B , 35B , 36B , 31D , 32D , 33D , and 35D were successfully purified by automated mass-triggered preparative HPLC in suitable amounts for biological evaluation . Taken as a whole, this study clearly supports the automated flow approach for library synthesis.…”

High-Throughput Purification in Drug Discovery: Scaling New Heights of Productivity

“…Advances in automated liquid–liquid extractions, , including microdroplets, and solid phase extraction (SPE)/​resin cleanup methods offer potentially faster and cheaper alternativesbut they cannot match the generic capabilities of C18 HPLC, with a wide compound structure range and high purity levels. Sample preparation, using SPE, for crude samples and advanced techniques of “trap and release” of “heart-cut” samples, combined with LCMS, offer the ultimate purification solution.…”

High-throughput crystallography for rapid fragment growth from crude arrays by low-cost robotics

“…In recent years, progress has been made in developing low-cost HTS platforms [23] for the synthesis, purification and analysis of compounds. [24][25][26][27] We previously completed a fragment screen against the second bromodomain of the pleckstrin homology domain-interacting protein (PHIP(2)), a multidomain protein involved in various cellular processes including cellular growth and mobility [18] that has been implicated in a number of aggressive cancers including BRAFnegative melanomas, breast and lung cancer. [28,29] Following up on the piperazine hit, F709, from this screen, we implemented a growth array synthesis exercise using a low-cost OpenTrons OT-1 TM robotics-based synthesis platform, which allows for a quick survey of the chemical space around a fragment hit.…”