RUI: Mono and Bis Gold Resorcinarenes: New, Potent Supramolecular Cataylsts

California State University-Long Beach Foundation, Long Beach CA

Investigators

Abstract

Efficient chemical transformations are essential for cost effective industrial synthesis of pharmaceuticals and manufacturing of commodity chemicals and useful materials. Inspired by enzymes (a type of protein) that catalyze chemical reactions in living organisms, Prof. Schramm conducts research to gain a better understanding of the principles for designing efficient catalysts and to develop new methodologies for chemical transformations. This project provides research training to undergraduate students and Master's degree candidates, including women and members of underrepresented groups. The researchers also have the opportunity to engage with collaborators in another country to broaden their perspectives in science. Through this process of discovery, they are trained to become experts in this area of study and help advance knowledge. Prof. Schramm and coworkers synthesize resorcinarene-based cavitiands with one or two coordinated gold(I) atoms for catalyzing the reactions of alkynes with nucleophiles. Inspired by the architectural principles of enzymes, these catalysts are designed to have a pocket for binding substrates (alkynes) and the catalytic functional groups (gold atoms) directed inwardly towards the binding pocket. There are three main thrusts in this project. The first objective focuses on studying chemical transformations catalyzed by a cavitand that has one gold(I) atom coordinated to a 3-walled resorcinarene. This research aims to differentiate the supramolecular catalyst with well-defined binding pocket from simpler gold catalysts and to evaluate the role of molecular recognition on substrate selectivity, regio- and diastereo-chemical properties of reaction products, and reaction rates. The second thrust explores the catalytic properties of bis-gold(I) cavitands. The confined space and placement of two adjacent gold atoms result in new modes of alkyne reactivity, e.g., yne-yne coupling reaction. The third thrust aims to gain a better understanding of the effect of the "walls" of the cavitands on stabilizing reactive intermediates and modulating reactivity. The long term goal of this project is to develop selection rules for recognition and for favoring specific reaction outcomes.