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

Automated Alkylation of Heteroaromatic Thioethers with Organozinc Reagents for Library Synthesis

In this study, we describe the implementation of an automated high-throughput workflow to efficiently functionalize medicinal-chemistry-relevant heteroaryl thioethers with diverse alkyl organozinc reagents in flow. The successful coupling observed with different aryl thioether substrates and organozinc reagents highlights the broad applicability of this platform for rapid library diversification. This platform greatly improves the speed and efficiency of modifying heteroaromatic thioethers featuring C(sp3) centers, thereby facilitating the discovery of novel bioactive compounds and positioning it as a valuable resource for medicinal chemistry projects.

Transition-Metal-Free Radical Relay Cascade Annulation of Amides: Access to Antitumor Active Benzo[b]azepine and Oxindole Derivatives

Efficient transition-metal-free synthesis of benzo[b]azepines and oxindoles is achieved via a radical relay cascade strategy employing halogen atom transfer (XAT) for aryl radical generation followed by intramolecular hydrogen atom transfer (HAT). Optimization yielded moderate to substantial yields under visible light irradiation. Preliminary biological assessments revealed promising anti-tumor activity for select compounds. This study underscores the potential of XAT-mediated radical relay cascades in medicinal chemistry and anticancer drug discovery.

Late-Stage C(sp2)-C(sp3) Diversification via Nickel Oxidative Addition Complexes

Herein, we describe nickel oxidative addition complexes (Ni-OACs) of drug-like molecules as a platform to rapidly generate lead candidates with enhanced C(sp3) fraction. The potential of Ni-OACs to access new chemical space has been assessed not only in C(sp2)-C(sp3) couplings but also in additional bond formations without recourse to specialized ligands and with improved generality when compared to Ni-catalyzed reactions. The development of an automated diversification process further illustrates the robustness of Ni-OACs, thus offering a new gateway to expedite the design-make-test-analyze (DMTA) cycle in drug discovery.

Deoxy-Arylation of Amides via a Tandem Hydrosilylation/Radical- Radical Coupling Sequence

Vaska's complex is a prominent catalyst for the hydrosilylation of amides. The O-silyl hemiaminal intermediate formed in these processes has been demonstrated as an electrophile for nucleophilic additions. More recently, these intermediates have been shown to be suitable for single electron reduction to generate α-amino radicals. Leveraging the ability to generate α-amino radicals from these hemiaminals, we describe a two-step, one-pot, deoxy-arylation of amides utilizing iridium-catalyzed hydrosilylation and photoredox catalysis. This transformation can be tailored toward the late-stage functionalization of biologically relevant molecules, with drug discovery applications as shown in the streamlined synthesis of an NPY Y2 inhibitor.