[2 + 1] Cycloaddition of Catalytic Ruthenium Vinyl Carbenes: A Stereoselective Controlled Access to (Z)- and (E)-Vinyl Epoxypyrrolidines

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• 作者：Damián PadínFermín Cambeiro ; Martín Fañanás-Mastral ; Jesús A. VarelaCarlos Saá
• 刊名：ACS Catalysis
• 出版年：2017
• 出版时间：February 3, 2017
• 年：2017
• 卷：7
• 期：2
• 页码：992-996
• 全文大小：481K
• ISSN：2155-5435

文摘

Aza-alkynals undergo a cyclization reaction with diazo compounds in the presence of catalytic amounts of Cp*RuCl(cod) to afford vinyl epoxypyrrolidines, valuable building blocks for the synthesis of biologically active molecules. Ruthenium vinyl carbene intermediates have been invoked to explain the overall [2 + 1] cycloaddition (epoxy-annulation reaction). The reaction proceeds under mild conditions and in short reaction times (5–80 min) with complete (Z)- or (E)-stereoselectivity on the vinyl substituent, depending on the nature of the diazo compound used. Theoretical calculations support a mechanistic rationale to explain this controlled process.