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Updated: Jul 9, 2025
Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
[3+2] Cycloaddition of Alkynyl Boronates and in situ Generated Azomethine Ylide
Oleksandr S Liashuk1,2, Ihor A Ryzhov1,2, Oleksandr V Hryshchuk1,2
1Enamine Ltd., Winston Churchill Street 78, Kyїv, 02094, Ukraine.
Abstract:
Scalable [3+2] cycloaddition of alkynyl boronates and in situ generated unstabilized azomethine ylide is reported for the first time. The selective formation of either 1 : 1 or 1 : 2 cycloaddition products was achieved by carefully optimizing the reaction conditions, mainly by controlling the reactant stoichiometry, catalyst loading, and internal temperature. The developed protocol tolerated many valuable functional groups, including TMS, protected alcohol (as ether or THP derivatives), or aldehyde (as acetal). Further common C-C and C-heteroatom bond-forming reactions, as well as scaled-up procedures demonstrate the utility of the prepared compounds as building blocks for organic synthesis and drug discovery.
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