EXPANDING ON HYDROAMINATIONS

Abstract

A RHODIUM CATALYST system conjured up by Zhijian Liu and John F. Hartwig of the University of Illinois, Urbana-Champaign, can catalyze intramolecular cyclizations of aminoalkenes under mild conditions ( J. Am. Chem. Soc. , DOI: 10.1021/ ja710126x). The reaction, when optimized, could significantly expand the scope of hydroaminations of olefins, one of the simplest ways to prepare alkylamines. The reactions proceed with unactivated aminoalkenes containing primary or secondary amines, terminal or internal alkenes, and linkers that possess or lack substituents that bias the substrate toward cyclization. In addition, the reactions occur at low temperature and aren’t disrupted by spectator functional groups. That diverse combination of possibilities, which is not matched by existing catalyst systems, leads to a variety of five- and six-membered-ring products, the researchers note. University of Michigan chemist Melanie S. Sanford, whose work has included rhodium-mediated cyclizations, comments that Liu and Har...