Chemical and theoretical tools for understanding iminium ion catalysis

Recent reports have shown that the use of cyclic five membered nitrogen contg. heterocycles as catalysts for the iminium ion catalyzed Diels-Alder, [3+2] and [4+3]-cycloaddns., as well as Michael addns. of pyrroles, anilines, nitroalkanes, malonates and hydride have met with remarkable levels of asym. induction. We have become interested in developing new catalyst architectures to accelerate this class of transformation with the ultimate aim of providing more efficient systems than those reported. Our approach resides in gaining a fundamental mechanistic understanding of the reaction and applying this knowledge to improve catalytic efficiency. Utilizing a combination of mol. modeling, kinetic investigations and solid-state structural anal. we have probed the catalytic cycle of the iminium ion catalyzed Diels-Alder cycloaddn. reaction. This talk will describe our results in each of these areas and ongoing efforts in using these to develop a predictive tool for catalyst activity in this fascinating class of chem. transformation. [on SciFinder(R)]