Indirect electrochemical reductive cyclization ofo-halophenylacrylamides mediated by phenanthrene

Abstract

3,4-dihydroquinolone is an important drug and biological compound molecule. o-halophenylacrylamides were cyclized by two-electron reduction under electrochemical catalysis to obtain the corresponding 3,4-dihydroquinolinone products. This electrochemical cyclization improves the selectivity...

Electroreduction strategy: a sustainable tool for the generation of aryl radicals

“…In 2024, Liang et al employed a cathodic two-electron reduction strategy to realize a practical phenanthrene-mediated intramolecular 6- endo cyclization of o -halophenylacrylamides, providing a convenient approach for the construction of a number of structurally diverse and valuable 3,4-dihydroquinolinone derivatives in moderate to good yields (Scheme 26). 58 Detailed deuterium-labeling experiments were carried out to elucidate the source of hydrogen atoms. Upon using o -bromophenylacrylamide as a substrate for this reaction in the presence of 10.0 equivalents of D 2 O, 65% D-incorporation was observed at the terminal position of the alkene, while the target product without a deuterium label was isolated in 79% yield using DMF- d 7 instead of D 2 O.…”

Electrochemical Coupling Reactions Using Non‐Transition Metal Mediators: Recent Advances

“…Polycyclic aromatic hydrocarbons (PAHs) are effective mediators for electro-reductive CÀ C bond forming reactions. [65][66][67][68][69][70][71][72] For instance, Liang reported electroreductive cyclization of ohalophenylacrylamides using phenanthrene as an organic mediator (Scheme 26). [65] The reductive coupling even proceeded without the mediator.…”

“…[65][66][67][68][69][70][71][72] For instance, Liang reported electroreductive cyclization of ohalophenylacrylamides using phenanthrene as an organic mediator (Scheme 26). [65] The reductive coupling even proceeded without the mediator. The addition of phenanthrene increased the yield of the products.…”

Construction of 3,4-Dihydroquinolone Derivatives through Pd-Catalyzed [4+2] Cycloaddition of Vinyl Benzoxazinanones with α-Alkylidene Succinimides

“…Approved drugs such as carteolol ( III , a nonselective β-adrenergic blocking agent), procaterol ( IV , a β 2 -adrenergic agonist), cilostazol ( V , a phosphodiesterase-3 inhibitor), abilify ( VI , an antipsychotic drug), and vesnarinone ( VII , a cardiotonic agent) also contain this structural motif. Due to their significant biological relevance, extensive efforts have been dedicated to the development of highly efficient synthetic strategies for accessing 3,4-dihydroquinolone derivatives …”