| Abstract
| - The halo and aryl substituents of the 1,2-disubstituted styryl group of aromatic enynes undergo a 1,2-shift in the aromatization reaction catalyzed by TpRuPPh3(CH3CN)2PF6 (10 mol %) in toluene (110 °C, 6−8 h). The aryl group shifts to the neighboring olefin carbon, and the iodo (or bromo) substituent migrates to the terminal alkyne carbon. The mechanisms of these two migrations have been elucidated by isotope labeling experiments. It indicates that the 1,2-aryl shift arises from 5-endo-dig electrocyclization of a ruthenium−vinylidene species, whereas the 1,2-iodo shift follows a 6-endo-dig pathway.
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