Cobalt-Catalyzed Formal [4+2] Cycloaddition of α,α′-Dichloro-<i>ortho</i>-Xylenes with Alkynes
作者:Kimihiro Komeyama、Yuji Okamoto、Ken Takaki
DOI:10.1002/anie.201406807
日期:2014.10.13
A formal [4+2] cycloaddition of α,α′‐dichloro‐ortho‐xylenes with various alkynes has been developed using a low‐valent cobalt catalyst. The transformation has a wide substrate scope and high functional‐group tolerance and led to 1,4‐dihydronaphthalenes. The formed cycloadducts were easily aromatized with MnO2 under air. A mechanistic investigation suggests that the transformation proceeds through a