Diastereoselectivity-Switchable and Highly Enantioselective 1,3-Dipolar Cycloaddition of Nitrones to Alkylidene Malonates
- 13 April 2004
- journal article
- Published by American Chemical Society (ACS) in Organic Letters
- Vol. 6 (10) , 1677-1679
- https://doi.org/10.1021/ol049460d
Abstract
Trisoxazoline 1/Co(ClO(4))(2).6H(2)O catalyzed the 1,3-cycloaddition between nitrones 3 with alkylidene malonates 2 at 0 degrees C to give the isoxazolidines with both high enantioselectivity and high exo selectivity. However, when the temperature was lowered from 0 to -40 degrees C, the same cycloaddition afforded endo isomers as the major products with good to high enantioselectivity. A mechanism is provided.Keywords
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