Kinetic Resolution of Cyclic Secondary Azides, Using an Enantioselective Copper-Catalyzed Azide–Alkyne Cycloaddition

An enantioselective copper-catalyzed azide–alkyne cycloaddition (E-CuAAC) is reported by kinetic resolution. Chiral triazoles were isolated in high yield with limiting alkyne (up to 97:3 enantiomeric ratio (er)). A range of substrates were tolerated (>30 examples), and the reaction was scaled to...

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Bibliographic Details
Published in:Organic letters 2019-06, Vol.21 (11), p.4355-4358
Main Authors: Alexander, Juliana R, Ott, Amy A, Liu, En-Chih, Topczewski, Joseph J
Format: Article
Language:English
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Summary:An enantioselective copper-catalyzed azide–alkyne cycloaddition (E-CuAAC) is reported by kinetic resolution. Chiral triazoles were isolated in high yield with limiting alkyne (up to 97:3 enantiomeric ratio (er)). A range of substrates were tolerated (>30 examples), and the reaction was scaled to >1 g. The er of a triazole product could be enhanced by recrystallization and the recovered scalemic azide could be racemized and recycled. Recycling the azide allows efficient use of the undesired azide enantiomer.
ISSN:1523-7060
1523-7052
DOI:10.1021/acs.orglett.9b01556