Palladium-catalyzed ionic liquid-accelerated oxidative annulation of acetylenic oximes with unactivated long-chain enols
A palladium-catalyzed ionic liquid-accelerated oxidative cascade annulation/functionalization of acetylenic oximes with unactivated long-chain enols under aerobic conditions was accomplished. This newly developed protocol provides the rapid and straightforward synthetic strategy for the assembly of structurally diverse isoxazole architectures under mild conditions with high atom- and step-economy and exceptional functional group tolerance. Notably, the ionic liquid acts as not only a solvent in the reaction but also provides the excess halide ions to eliminate hydrochloride from acetylenic oximes. Moreover, this catalytic system could be recycled up to eight times and reused without significant loss of the catalytic activity.
Palladium-Catalyzed Cascade Annulation/Allylation of Alkynyl Oxime Ethers with Allyl Halides: Rapid Access to Fully Substituted Isoxazoles
A novel and efficient approach for the synthesis of functionalized isoxazoles via palladium-catalyzed cascade annulation/allylation of alkynyl oxime ethers with allyl halides has been established. The present protocol exhibits mild reaction conditions, good functional group compatibility, and convenient operation. Moreover, scalability was performed and further decoration of the isoxazole product was achieved.
Synthesis method of 4-allyl-3,5-disubstituted isooxazole
The invention discloses a synthesis method of 4-allyl-3,5-disubstituted isooxazole, and belongs to the technical field of organic synthesis. The synthesis method is characterized in that in a reactor,acetyenic ketone oxime ether substrates, 3-bromopropyle
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Paragraph 0051; 0052; 0053; 0059
(2018/12/13)
Direct synthesis of trisubstituted isoxazoles through gold-catalyzed domino reaction of alkynyl oxime ethers
Alkynyl oxime ether underwent a gold-catalyzed domino reaction involving cyclization and subsequent Claisen-type rearrangement to afford trisubstituted isoxazoles in a direct, efficient, and regioselective manner. The products were successfully applied to the synthesis of unusual heterocycles as an illustration of the potential utility of the reaction.