Directing the Activation of Donor-Acceptor Cyclopropanes Towards Stereoselective 1,3-Dipolar Cycloaddition Reactions by Brønsted Base Catalysis
作者:Jakob Blom、Andreu Vidal-Albalat、Julie Jørgensen、Casper L. Barløse、Kamilla S. Jessen、Marc V. Iversen、Karl Anker Jørgensen
DOI:10.1002/anie.201706150
日期:2017.9.18
first stereoselective organocatalyzed [3+2] cycloaddition reaction of donor-acceptor cyclopropanes is presented. By using 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 threecontiguous stereocenters