Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania15260, United States.
School of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu225002, China.
J Am Chem Soc. 2022 Aug 31;144(34):15480-15487. doi: 10.1021/jacs.2c07297. Epub 2022 Aug 17.
An iridium-catalyzed stereoselective coupling of allylic ethers and alkynes to generate 3,4-substituted 1,5-enynes is reported. Under optimized conditions, the coupling products are formed with excellent regio-, diastereo-, and enantioselectivities, and the protocol is functional group tolerant. Moreover, we report conditions that allow the reaction to proceed with complete reversal of diastereoselectivity. Mechanistic studies are consistent with an unprecedented dual role for the iridium catalyst, enabling the propargylic deprotonation of the alkyne through π-coordination, as well as the generation of a π-allyl species from the allylic ether starting material.
报道了铱催化的烯丙基醚和炔烃的立体选择性偶联反应，生成 3,4-取代的 1,5-烯炔。在优化条件下，该偶联反应以优异的区域、非对映和对映选择性形成偶联产物，且该反应对官能团具有耐受性。此外，我们还报告了可以使反应完全反转非对映选择性的条件。反应机理研究与铱催化剂前所未有的双重作用一致，该作用可以通过π-配位使炔烃发生丙二烯基去质子化，同时从烯丙基醚起始原料生成π-烯丙基物种。
