Simultaneous Induction of Axial and Planar Chirality in Arene–Chromium Complexes by Molybdenum‐Catalyzed Enantioselective Ring‐Closing Metathesis |
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Authors: | Prof.Dr. Ken Kamikawa Dr. Sachie Arae Dr. Wei‐Yi Wu Chihiro Nakamura Prof.Dr. Tamotsu Takahashi Prof.Dr. Masamichi Ogasawara |
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Affiliation: | 1. Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599‐8531 (Japan), Fax: (+81)?72‐254‐9931;2. Catalysis Research Center and Graduate School of Life Science, Hokkaido University, Kita‐ku, Sapporo 001‐0021 (Japan), Fax: (+81)?11‐706‐9150 |
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Abstract: | The molybdenum‐catalyzed asymmetric ring‐closing metathesis of the various Cs‐symmetric (π‐arene)chromium substrates provides the corresponding bridged planar‐chiral (π‐arene)chromium complexes in excellent yields with up to >99 % ee. With a bulky and unsymmetrical substituent, such as N‐indolyl or 1‐naphthyl, at the 2‐positions of the η6‐1,3‐diisopropenylbenzene ligands, both biaryl‐based axial chirality and π‐arene‐based planar chirality are simultaneously induced in the products. The axial chirality is retained even after the removal of the dicarbonylchromium fragment, and the chiral biaryl/heterobiaryl compounds are obtained with complete retention of the enantiopurity. |
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Keywords: | asymmetric synthesis chromium desymmetrization metathesis molybdenum |
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