Nucleophilic Cyclopropanation Reaction with Bis(iodozincio)methane by 1,4‐Addition to α,β‐Unsaturated Carbonyl Compounds |
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Authors: | Kenichi Nomura Takaharu Hirayama Seijiro Matsubara Prof. |
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Affiliation: | Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoutodaigaku‐katsura, Nishikyo‐ku, Kyoto 615‐8510 (Japan), Fax: (+81)?75‐383‐2463 |
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Abstract: | Treatment of α,β‐unsaturated ketones with an electrophilic site at the γ‐position in the presence of trimethylsilyl cyanide with bis(iodozincio)methane afforded the (Z)‐silyl enol ether of the β‐cyclopropyl substituted ketone in good yields. The reaction proceeds by 1,4‐addition to form an enolate, and its sequential intramolecular nucleophilic attack to an adjacent electrophilic site. The reaction of γ‐ethoxycarbonyl‐α,β‐unsaturated ketone and bis(iodozincio)methane in the presence of trimethylsilyl cyanide afforded 1‐ethoxy‐1‐trimethylsiloxycyclopropane derivatives, which can be regarded as the homoenolate equivalent. Additionally, reaction of the obtained homoenolate equivalents with imines give 1‐(E)‐alkenyl‐2‐(1‐aminoalkyl)alkanols diastereoselectively. |
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Keywords: | cyclopropanation diastereoselectivity enols nucleophilic addition silylation |
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