37436-31-0Relevant academic research and scientific papers
Rutheniun-catalyzed cycloisomerization of o-(ethynyl)phenylalkenes to diene derivatives via skeletal rearrangement
Madhushaw, Reniguntala J.,Lo, Ching-Yu,Hwang, Chun-Wei,Su, Ming-Der,Shen, Hung-Chin,Pal, Sitaram,Shaikh, Isak R.,Liu, Rai-Shung
, p. 15560 - 15565 (2007/10/03)
Treatment of a series of 2′,2′-disubstituted (oethynyl)styrenes with TpRu(PPh3)(CH3CN)2PF6 (10 mol %) in benzene (80°C, 12-18 h) efficiently gave 2-alkenyl-1H-indene derivatives. This catalytic reaction represents an atypical enyne cycloisomerization with skeletal rearrangement of starting enyne, where the C=C bond is completely cleaved and inserted by the terminal alkynyl carbon. The reaction mechanism was elucidated by a series of deuterium and 13C labeling experiments, as well as by changing the substituents at the phenyl moieties. The mechanism is proposed to involve the following key steps: 5-endo-dig cyclization of ruthenium-vinylidene intermediate, a nonclassical ion formation, and the "methylenecyclopropane-trimethylenemethane" rearrangement.
