Palladium‐Catalyzed Sequential Cyclization/Functionalization of Oxime Ethers with Unactivated Vinyl Ethers for Tunable Assembly of Structurally Diverse Isoxazoles. Issue 12 (10th October 2021)

• Record Type: Journal Article
• Authors: Li, Jianxiao; Lin, Zidong; He, Dan; Wu, Wanqing; Jiang, Huanfeng
• Is Part Of: Chinese journal of chemistry. Volume 39:Issue 12(2021)
• Page Start: 3285
• Page End: 3291
• Publication Date: 2021-10-10
• Subjects: Palladium -- Alkenes -- Alkynes -- Annulation -- Cross‐coupling; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cjoc.202100482
• Languages: English
• ISSNs: 1001-604X

Abstract

Main observation and conclusion: A novel and viable palladium‐catalyzed sequential cyclization/functionalization of alkynone O ‐methyloximes with unactivated vinyl ethers under aerobic conditions was described. The structure of the products could be successfully controlled by varying the nature of the substituents of the vinyl ethers. This new approach provides a convenient and straightforward synthetic protocol for the preparation of structurally diverse 4‐(1‐alkoxyvinyl)‐isoxazoles and 4‐vinylisoxazoles in moderate to good yields with highly regioselectivity. Remarkably, this protocol can be performed on a gram scale, showing the promising application in synthetic and pharmaceutical chemistry. Abstract : A palladium‐catalyzed sequential cyclization/functionalization of O ‐methyl oximes and unactivated vinyl ethers under aerobic conditions was described. The structure of the products could be successfully regulated by varying the electrical property of the substituents of the vinyl ethers. This new approach provides a convenient and effective protocol for the preparation of a great variety of 4‐(1‐alkoxyvinyl)‐isoxazoles and 4‐vinylisoxazoles in moderate to good yields with high regioselectivity.