<h3>Title</h3>
<h3>Targeting Privileged Heterocycles through Organocascade Catalysis</h3>
<p><strong><span style="text-decoration: underline;">Abstract</span> :</strong></p>
<p style="text-align: justify;">Discovery of reactive intermediates via new generic modes of substrate activation is central to the field of asymmetric catalysis. In this context, there has been a significant expansion of the reactions that catalyzed by tertiary amines. The advent of tertiary amine catalysis introduced two new activation modes of acid chlorides: displacement of the chlorine atom by a tertiary amine generates an electrophilic acylammonium, while subsequent deprotonation at the α-position affords a nucleophilic ammonium enolate intermediate. Recently, we have uncovered a third activation mode, by which reactivity of these acid chlorides can be modulated by insitu generation of chiral α,β-unsaturated acylammonium salts with cinchona alkaloid catalysts. In this talk, I will discuss the reaction of these intermediates with bisnucleophiles that enabled a one-pot, enantioselective strategy to privileged heterocycles such as pyrrolidinones, 2-piperid-2-ones and dihydropyridinone through organocascade catalysis. The utility of this method in the syntheses of a pyroglutamic acid derivative, which is previously employed for the synthesis of an FDA approved drug baclofen, clinical candidate chlorpheg and a potent α1a-adrenergic receptor antagonist will also be discussed. The talk will conclude with a brief discussion on future research plans.</p>
<p>Selected References</p>
<p>1. Gaunt, M. J. Johansson, C. C. C. Chem. Rev. 2007, 107, 5596.<br />2. Grondal, C.; Jeanty, M.; Enders, D. Nat. Chem. 2010, 2, 167.<br />3. Muller, C. E.; Schreiner, P. R. Angew. Chem. Int. Ed. 2011, 50, 6012.<br />4. Vellalath, S, Van, K. N.; Romo, D. Angew. Chem., Int. Ed. 2013, 52, 13688.<br />5. Robinson, E. R. T.; Fallan, C.; Simal, C.; Slawin, A. M. Z.; Smith, A. D. Chem. Sci.    2013, 4, 2193.</p>