Delineating Mechanistic Complexity After the Turnover-Limiting Step: The Secret Lives of Cu(l)-Acetylides

Seminar series
Organic Colloquium
Thu, Oct 25 4:00pm
Franz Hall 1178
Speaker Jason Hein
University of British Columbia
Department of Chemistry

Abstract: σ-Copper acetylides represent a very versatile class of reactive intermediates, common to a plethora of Cu(I)-catalyzed transformation of terminal alkynes. A particularly attractive feature of these intermediates is their ability to deliver target products with exquisite chemo- and regioselectivity, despite synthetic conditions, which on their surface, should allow for competing reaction pathways to persist. Controlling and explaining the superior selectivity of these processes requires a detailed understanding of all ancillary equilibria within a complex reaction network. Ultimately, a fundamental understanding of the ensemble of associated equilibria present within these synthetic transformations is critical for the development of practical applications.

In order to efficiently study such complex reaction networks, my group has developed an approach that leverages a combination of in-situ reaction monitoring techniques, including ReactIR, reaction calorimetry and automated reaction sampling. This tandem application of process analytical technology allows us to rapidly deconvolute convoluted pathways and competing reactions, reducing complex kinetic analysis to simple pattern recognition. This new mode of reaction analysis is exceptionally well suited to study multicomponent reactions with a variety of competing processes. Application of these techniques to delineate the underlying catalytic networks involving σ-copper acetylides will be discussed.