Enantioselective Synthesis of Highly Functionalized Dihydrofurans through Copper‐Catalyzed Asymmetric Formal [3+2] Cycloaddition of β‐Ketoesters with Propargylic Esters |
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Authors: | Fu‐Lin Zhu Ya‐Hui Wang De‐Yang Zhang Prof. Dr. Jie Xu Prof. Dr. Xiang‐Ping Hu |
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Affiliation: | 1. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China) http://www.asym.dicp.ac.cn;2. University of Chinese Academy of Sciences, Beijing 100049 (China) |
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Abstract: | An enantioselective synthesis of highly functionalized dihydrofurans through a copper‐catalyzed asymmetric [3+2] cycloaddition of β‐ketoesters with propargylic esters has been developed. With a combination of Cu(OTf)2 and a chiral tridentate P,N,N ligand as the catalyst, a variety of 2,3‐dihydrofurans bearing an exocyclic double bond at the 2 position were obtained in good chemical yields and with good to high enantioselectivities. The exocyclic double bond can be hydrogenated in a highly diastereoselective fashion to give unusual cis‐2,3‐dihydrofuran derivatives, thus further enhancing the scope of this transformation. |
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Keywords: | 2,3‐dihydrofurans asymmetric catalysis copper cycloadditions synthetic methods |
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