2-Arylbenzoylchlorides undergo annulativecoupling with internal alkynes in the presence of a catalyst system of [IrCl(cod)]2/P(t-Bu)3 to selectively afford the corresponding phenanthrenederivatives accompanied by elimination of carbon monoxide and hydrogen chloride. The reaction occurs without addition of any external base. Deuterium-labeling experiments using 2-(d5-phenyl)benzoyl chloride suggest
A rhodium-catalyzedannulative coupling of (2-arylphenyl)boronic acids with alkynes has been developed for the facile construction of phenanthrene frameworks. The reaction proceeded without external bases, and dioxygen worked as a terminal oxidant. Deuterium-labeling experiments indicated the involvement of five-membered rhodacycle intermediates.
Extended Study of Visible-Light-Induced Photocatalytic [4 + 2] Benzannulation: Synthesis of Polycyclic (Hetero)Aromatics
作者:Tanmay Chatterjee、Da Seul Lee、Eun Jin Cho
DOI:10.1021/acs.joc.7b00413
日期:2017.4.21
extended study of [4 + 2] benzannulation reactions of 2-(hetero)aryl-substituted anilines with alkynes by visible light photocatalysis. The method requires the use of tBuONO as a diazotizing agent and 0.3 mol % of fac-Ir(ppy)3 as a photocatalyst at room temperature. The reaction proceeded in a chemo- and regioselective manner with high functionalgroup tolerance under mild conditions allowing the preparation
Synthesis of Fluorenes<i>via</i>the Palladium-Catalyzed 5-<i>exo-dig</i>Annulation of<i>o</i>-Alkynylbiaryls
作者:Natalia Chernyak、Vladimir Gevorgyan
DOI:10.1002/adsc.200800765
日期:2009.5
The direct Pd-catalyzed intramolecular rapidly with electron-deficient benzene ring, which, in hydroarylation of o-alkynyl biaryls proceeded in highly combination with a substantial isotope effect observed, stereoselective manner producing fluorenes 2, the products of 5-exo-dig cyclization, in excellent yields. The cascade intermolecular arylation, incorporated in this transformation, allowed for efficient