Nickel‐Catalyzed Cyclopropanation with NMe4OTf and nBuLi |
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Authors: | Stefan A Künzi Dr Juan Manuel Sarria?Toro Dr Tim den?Hartog Prof?Dr Peter Chen |
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Institution: | 1. Laboratorium für Organsiche Chemie, ETH Zürich, Vladimir‐Prelog‐Weg 2, 8093 Zürich (Switzerland);2. Present address: ICIQ, Av. Pa?sos Catalan 16, 43007 Tarragona (Spain);3. Present address: Institut für Technische und Makromol. Chemie, RWTH Aachen University, Worringerweg 1, 52075 Aachen (Germany) |
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Abstract: | Nickel was identified as a catalyst for the cyclopropanation of unactivated olefins by using in situ generated lithiomethyl trimethylammonium triflate as a methylene donor. A mechanistic hypothesis is proposed in which the generation of a reactive nickel carbene explains several interesting observations. Additionally, our findings shed light on a report by Franzen and Wittig published in 1960 that had been retracted later owing to irreproducibility, and provide a rational basis for the systematic development of the reaction for preparative purposes as an alternative to diazomethane or Simmons–Smith conditions. |
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Keywords: | carbenes cyclopropanation nickel ylides |
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