In chapter 1 the discovery of chameleon catalysts was discussed. The chameleon catalyst was defined as an agent that can catalyze different reactions with different mechanisms. We have found that a chiral biaryl borate ester with two VANOL ligands and one boron complex is an extremely active catalyst for the epoxidation of aldehydes and the aziridination of imines. Mechanistic investigation revealed that this catalyst can catalyze epoxidation aziridination reactions with a different mechanism. We have shown that the aforementioned catalyst acts as a Lewis acid in the epoxidation of aldehydes and Bronsted acid in the aziridination of imines. X-ray structural analysis, Hammett study, and 11B-NMR study support our hypothesis.In chapter two the discovery and utility of the aluminum VAPOL catalyst and aluminum VANOL catalyst were explored. We have found that a chiral biaryl aluminum with two VAPOL ligands and one aluminum complex is an extremely active catalyst for the epoxidation of aldehydes with diazo acetamide. The excellent performance of aluminum VAPOL catalyst has also shown in the total synthesis of (-)-tedanalactam which was accomplished in only 5 steps with excellent enantioinduction in 37% overall yield. The aluminum catalyst also performed well in the aziridination reaction transforming the imine into the aziridine with good yield and excellent ee. We believe the aluminum catalyst also acts as a chameleon; however, more experiments are required to show the chameleon behavior of these complexes.In chapter three, inspired by Benjamin List's imidodiphosphorimidate catalysts, VANOL imidodiphosphorimidate (VIP) and VAPOL imidodiphosphorimidate (VAPIP) catalysts were synthesized. X-ray structural analysis aided us to perform crystal engineering on VIP derivatives and design a highly efficient VIP catalyst for the asymmetric halonium-ion induced spiroketalization. VIP catalysts were also explored in the asymmetric intramolecular Schmidt reaction; however, no asymmetric induction was observed after exploring the reaction with a library of these catalysts.
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