Visible-light-driven multicomponent reactions: Concurrent pyridylation and alkylation of styrenes

Given the prevalence of pyridines in pharmaceuticals, methods for regioselectively introducing functional groups to the pyridine ring offer a categorical yet sustainable challenge strategy for expanding drug-like chemical space. Herein, a visible-light-induced multicomponent reaction for the convenient construction of C-4 pyridine-functionalized scaffolds from readily available diazo compounds, alkenes and 4-cyanopyridines is disclosed. Distinct from the classical reaction of diazo compounds with pyridine to generate pyridinium ylides, this transformation proceeds via alkyl radical intermediates generated from diazo compounds, which subsequently undergo coupling with both pyridine-derived radicals and alkenes to achieve alkene difunctionalization through concurrent alkylation and pyridylation. This operationally simple transformation proceeds under mild conditions and features a broad substrate scope with excellent functional group tolerance. These advantages establish a versatile platform for constructing pyridine-functionalized molecular scaffolds. Herein, we disclose a visible-light-induced multicomponent reaction for the direct C-4 pyridylation and alkylation of alkenes using diazo compounds and 4-cyanopyridines. This practical method operates via a radical mechanism, distinct from classical pyridinium ylide pathways, to efficiently access functionalized pyridine scaffolds under mild conditions with broad substrate scope.