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Directing the Activation of Donor–Acceptor Cyclopropanes Towards Stereoselective 1,3‐Dipolar Cycloaddition Reactions by Brønsted Base Catalysis
Author(s) -
Blom Jakob,
VidalAlbalat Andreu,
Jørgensen Julie,
Barløse Casper L.,
Jessen Kamilla S.,
Iversen Marc V.,
Jørgensen Karl Anker
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201706150
Subject(s) - stereoselectivity , chemistry , cycloaddition , stereocenter , cyclopropane , catalysis , brønsted–lowry acid–base theory , organocatalysis , acceptor , stereochemistry , organic chemistry , enantioselective synthesis , medicinal chemistry , ring (chemistry) , physics , condensed matter physics
The first stereoselective organocatalyzed [3+2] cycloaddition reaction of donor‐acceptor cyclopropanes is presented. It is demonstrated that by applying an optically active bifunctional Brønsted base catalyst, racemic di‐cyano cyclopropylketones can be activated to undergo a stereoselective 1,3‐dipolar reaction with mono‐ and polysubstituted nitroolefins. The reaction affords functionalized cyclopentanes with three consecutive stereocenters in high yield and stereoselectivity. Based on the stereochemical outcome, a mechanism in which the organocatalyst activates both the donor‐acceptor cyclopropane and nitroolefin is proposed. Finally, chemoselective transformations of the cycloaddition products are demonstrated.