کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1326049 | 1499953 | 2005 | 9 صفحه PDF | دانلود رایگان |
The reaction of N-allyl-ortho-vinylaniline with ruthenium carbene catalyst at 50 °C gives substituted 1,2-dihydroquinoline through ring-closing metathesis (RCM), which is easily converted to the corresponding quinoline after deprotection. In sharp contrast, when vinyloxytrimethylsilane is added to this reaction mixture, 1,2-dihydroquinoline is not formed and selective isomerization of N-allyl-ortho-vinylaniline is observed at 50 °C to give corresponding enamide, which is successfully converted to indole derivative by RCM. The same catalyst system provide indoline derivative at 160 °C by cycloisomerization. Based on a detailed mechanistic study, it becomes clear that a ruthenium carbene catalyst, which is highly effective for RCM, reacts with an electron-rich terminal olefin selectively, and another ruthenium species, which effectively catalyzes the isomerization of terminal olefin and cycloisomerization of alpha, omega-diene, is generated.
Second generation Grubbs ruthenium carbene catalyst, which is highly effective for ring-closing metathesis (RCM), reacts with an electron-rich terminal olefin selectively, and another ruthenium species, which effectively catalyzes the isomerization of terminal olefin and cycloisomerization of alpha, omega-diene, is generated.Figure optionsDownload as PowerPoint slide
Journal: Journal of Organometallic Chemistry - Volume 690, Issues 24–25, 1 December 2005, Pages 5398–5406