O-Dihaloarenes as aryne precursors for nickel-catalyzed [2 + 2 + 2] cycloaddition with alkynes and nitriles
作者:Jen-Chieh Hsieh、Chien-Hong Cheng
DOI:10.1039/b801870g
日期:——
o-Dihaloarenes acting as aryne precursors react with acetylenes and nitriles catalyzed by the NiBr(2)(dppe)/dppe/Zn system to give substituted naphthalene, phenanthridine or triphenylene derivatives depending on the reaction conditions in moderate to excellent yields with good tolerance of functional groups.
Room Temperature Decarboxylative and Oxidative [2+2+2] Annulation of Benzoic Acids with Alkynes Catalyzed by an Electron‐Deficient Rhodium(III) Complex
It has been established that an electron‐deficient (η5‐cyclopentadienyl)rhodium(III) [CpERhIII] complex is capable of catalyzing the decarboxylative and oxidative [2+2+2] annulation of benzoic acids with alkynes to produce substituted naphthalenes at room temperature. The appropriate choice of the additive and the solvent is crucial for this transformation. This catalyst system allowed use of oxygen
The rhodium-catalyzed oxidative 1:2 coupling reactions of arylboronic acids or their esters with alkynes smoothly proceed to produce the corresponding annulated products. Of special note, highly substituted, readily soluble, and tractable anthracene and tetracene derivatives can be obtained selectively from 2-naphthyl- and 2-anthrylboron reagents, respectively.
The rhodium-catalyzedoxidative 1:2 coupling reactions of arylboronic acids with alkynes effectively proceeds in the presence of a copper−air oxidant to produce the corresponding annulated products. Of special note, anthracene derivatives can be obtained selectively from 2-naphthylboronic acids.
[GRAPHICS]The rhodium-catalyzed oxidative coupling of triarylmethanols with internal alkynes effectively proceeds in a 1:2 manner via cleavage of C-H and C-C bonds to produce the corresponding naphthalene derivatives. Addition of trior tetraphenylcyclopentadiene as a ligand is crucial for the reaction to occur efficiently.