Simple diamine- and triamine-protonic acid catalysts for the enantioselective Michael addition of cyclic ketones to nitroalkenes

J Am Chem Soc. 2006 Aug 2;128(30):9624-5. doi: 10.1021/ja062701n.

Abstract

Simple, chiral, pyrrolidine-based diamine and triamine derivatives that incorporate the secondary-secondary diamine motif are efficient catalysts for the highly diastereoselective and enantioselective Michael addition of cyclic ketones to 2-nitrovinyl arenes. The highest selectivities are obtained when these catalysts are used in conjunction with protonic acids. Steric factors in the substrate and the size of the acid additive play an important role in stereoselection.