Copper‐Catalyzed Formal [4+2] Cycloaddition of Enoldiazoimides with Sulfur Ylides |
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| Authors: | Dr Qing‐Qing Cheng Lynée A Massey Brook S Willett Dr Yongming Deng Dr Hadi Arman Prof?Dr Michael P Doyle |
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| Institution: | 1. http://www.utsa.edu/chem/faculty/DoyleLab/
0000-0001-6554-1789
Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX, USA;2. Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX, USA;3. Current address: Department of Chemistry, Western Kentucky University, Bowling Green, KY, USA |
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| Abstract: | Enoldiazoimides, a new subclass of enoldiazo compounds, generate enol‐substituted carbonyl ylides whose reactions with sulfur ylides enable an unprecedented formal 4+2] cycloaddition. The resulting multifunctionalized indolizidinones, which incorporate sulfur, are formed in good yields under mild reaction conditions. The uniqueness of this transformation stems from the role of the silyl‐protected enol, since the corresponding acetyldiazoimide failed to provide any cross‐products in metal‐catalyzed reactions with sulfur ylides. This copper‐catalyzed cycloaddition is initiated with the generation of enol‐substituted carbonyl ylides and sulfur ylides from enoldiazoimides and sulfonium salts, respectively, and proceeds through stepwise six‐membered ring formation, C?O and C?S bond cleavage, and silyl and acetyl group migration. |
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| Keywords: | copper cycloaddition diazo compounds sulfonium salts ylides |
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