“Formal” Ruthenium-Catalyzed [4+2+2] Cycloaddition of 1,6-Diynes to 1,3-Dienes: Formation of Cyclooctatrienes vs Vinylcyclohexadienes
作者:Jesús A. Varela、Luis Castedo、Carlos Saá
DOI:10.1021/ol0348710
日期:2003.8.1
[reaction: see text] A new "formal" Ru-catalyzed [4+2+2] cycloaddition of 1,6-diynes to 1,3-dienes giving conjugated 1,3,5-cyclooctatrienes and vinylcyclohexadienes is described. This formal cycloaddition is really a tandem process, the Ru(II)-catalyzed formation of (Z)-tetraenes or vinyl-(Z)-trienes followed by a pure thermal conrotatory 8 pi- or disrotatory 6 pi-electrocyclization. The proposed mechanism