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The development of site‐selective functionalization of N‐heteroarenes is highly desirable in streamlined synthesis. In this context, direct amination of pyridines stands as an important synthetic methodology, with particular emphasis on accessing 4‐aminopyridines, a versatile pharmacophore in medicinal chemistry. Herein, we report a reaction manifold for the C4‐selective amination of pyridines by employing nucleophilic substitution of hydrogen (SNH). Through 4‐pyridyl pyridinium salt intermediates, 4‐aminopyridine products are obtained in reaction with aqueous ammonia without intermediate isolation. The notable regioselectivity was achieved by the electronic tuning of the external pyridine reagents along with the maximization of polarizability in the proton elimination stage. Further mechanistic investigations provided a guiding principle for the selective C−H pyridination of additional N‐heteroarenes, presenting a strategic avenue for installation of diverse functional groups. [ABSTRACT FROM AUTHOR]

The development of site‐selective functionalization of N‐heteroarenes is highly desirable in streamlined synthesis. In this context, direct amination of pyridines stands as an important synthetic methodology, with particular emphasis on accessing 4‐aminopyridines, a versatile pharmacophore in medicinal chemistry. Herein, we report a reaction manifold for the C4‐selective amination of pyridines by employing nucleophilic substitution of hydrogen (SNH). Through 4‐pyridyl pyridinium salt intermediates, 4‐aminopyridine products are obtained in reaction with aqueous ammonia without intermediate isolation. The notable regioselectivity was achieved by the electronic tuning of the external pyridine reagents along with the maximization of polarizability in the proton elimination stage. Further mechanistic investigations provided a guiding principle for the selective C−H pyridination of additional N‐heteroarenes, presenting a strategic avenue for installation of diverse functional groups. [ABSTRACT FROM AUTHOR]

Herein, the selective ortho‐ and meta‐C−H bond borylation of NH‐aryl sulfoximines is reported. Regioselectivity is achieved by the choice of commercially available ligands giving fast excess to valuable borylated aryl sulfoximine building blogs. The utility of the borylated products is demonstrated for the formation of C−O, C−C, C−N, C−D, and C−I bonds. [ABSTRACT FROM AUTHOR]

Mechanochemical approaches are widely used for the efficient, solvent‐free synthesis of organic molecules, however their applicability to the synthesis of functional polymers has remained underexplored. Herein, we demonstrate for the first time that mechanochemically triggered free‐radical polymerization allows solvent‐ and initiator‐free syntheses of structurally and morphologically well‐defined complex functional macromolecular architectures, namely stimuliresponsive microgels. The developed mechanochemical polymerization approach is applicable to a variety of monomers and allows synthesizing microgels with tunable chemical structure, variable size, controlled number of crosslinks and reactive functional end‐groups. [ABSTRACT FROM AUTHOR]

Mechanochemical approaches are widely used for the efficient, solvent‐free synthesis of organic molecules, however their applicability to the synthesis of functional polymers has remained underexplored. Herein, we demonstrate for the first time that mechanochemically triggered free‐radical polymerization allows solvent‐ and initiator‐free syntheses of structurally and morphologically well‐defined complex functional macromolecular architectures, namely stimuliresponsive microgels. The developed mechanochemical polymerization approach is applicable to a variety of monomers and allows synthesizing microgels with tunable chemical structure, variable size, controlled number of crosslinks and reactive functional end‐groups. [ABSTRACT FROM AUTHOR]

A mechanochemical synthesis of diarylethynes from aryl iodides and calcium carbide as acetylene source is reported. The reaction is catalyzed by a palladium catalyst in the presence of copper salt, base, and ethanol as liquid assisting grinding (LAG) additive. Various aryl and heteroaryl iodides have been converted in up to excellent yields. [ABSTRACT FROM AUTHOR]