Intermolecular 1,3-Dipolar Cycloaddition Reaction of N-Carbamoyl Nitrones Generated by N-Selective Carbamoylation of
Ayaka Yamamoto1, Kosaku Tanaka1,2, Yoshimitsu Hashimoto1
1Showa Pharmaceutical University, Higashi-Tamagawagakuen, 194-8543, Machida, Tokyo, Japan.
Abstract:
N-Selective carbamoylation reaction of oximes with isocyanates generates nitrones, which undergo 1,3-dipolar cycloaddition with various dipolarophiles to afford diverse isoxazolidines. Notably, combinations of highly electron-rich oxime and highly electron-deficient dipolarophile exhibited high reactivity, with product yields of up to 94 %. The substituent on the isoxazolidine-nitrogen atom could be successfully removed without loss of the cyclic structure. Computational studies have also elucidated the mechanism of the reaction and origin of stereoselectivity.
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