This work describes an electrochemicalammoniumcation enabled hydropyridylation of ketone-activated alkenes under metal- and exogenous reductant free conditions giving access to β-pyridyl ketones, through dual proton-coupled electron transfer and radical cross-coupling. It features a broad substrate scope and allows a gram-scale synthesis. Ammonium chloride plays various roles in this transformation
flavanones, which included polycyclic aromatic and heterocyclic rings, were readily synthesized via oxa-Michael addition from the corresponding hydroxychalcones with a catalytic amount of aqueous cesium fluoride solution under mild conditions. This method could be applied to the scalable synthesis of eriodictyol as a known potent inhibitor of the SARS-CoV-2 spike protein.
An electroreductive 4-pyridylation of activated alkenes was developed in an undivided cell with the assistance of Ni(acac)(2) (acac = acetylacetone). This novel protocol is compatible with a broad range of electron-poor alkenes, which are commonly regarded as challenging substrates in the previous conventional approaches. Moreover, a series of cyclic voltammetric experiments were conducted to reveal the unique role of Ni(acac)(2) differentiating reduction process of reaction partners.