Rhodium- and Iridium-Catalyzed Oxidative Coupling of Benzoic Acids with Alkynes via Regioselective C−H Bond Cleavage
作者:Kenji Ueura、Tetsuya Satoh、Masahiro Miura
DOI:10.1021/jo070735n
日期:2007.7.1
coupling of benzoicacids with internal alkynes effectively proceeds in the presence of [Cp*RhCl2]2 and Cu(OAc)2·H2O as catalyst and oxidant, respectively, to produce the corresponding isocoumarin derivatives. The copper salt can be reduced to a catalytic quantity under air. Interestingly, by using [Cp*IrCl2]2 in place of [Cp*RhCl2]2, the substrates undergo 1:2 coupling accompanied by decarboxylation to afford
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.