Photoredox catalysis has recently emerged as an effective strategy for the synthesis of new compounds. In such reactions, a catalyst absorbs light to reach an excited state, and then initiates an electron transfer reaction. Most existing reports of this technique have used ruthenium or iridium catalysts; however, these metals are high in both price and toxicity, and thus we aim to develop more sustainable alternatives. We have hypothesized that copper could be utilized as a replacement, as it is earth-abundant, safe, and relatively inexpensive. Furthermore, copper complexes are known with photophysical properties similar to the ruthenium photoredox catalyst Ru(bpy)<sub>3</sub>Cl<sub>2</sub>. This promise has led us to evaluate the use of copper complexes as catalysts in photoredox reactions. Specifically, we are focusing on the use of bis(phenanthroline) copper(I) derivatives as catalysts in the enantioselective α-alkylation of aldehydes – a reaction that also uses a chiral catalyst to control facial selectivity. In the course of this investigation, we have tested a number of copper(I) complexes under a range of reaction conditions. Our results suggest that ligand substitution has a significant effect on reactant conversion and product yield. During this presentation, we will share data from specific trials, show how yield was affected by a variety of factors, and provide an analysis of these complexes in comparison to conventional photocatalysts.

Evaluation of copper photocatalysts in the enantioselective α-alkylation of aldehydes

249th National Meeting (2015)

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