Synthesis of Various Water Soluble and Stable Copper Complexes Bearing N-Heterocyclic Carbene Ligands and Their Activity in DNA Alkylation

Abstract

We report here the synthesis and catalytic evaluation in DNA alkylation of a series of water-soluble copper complexes bearing N-heterocyclic carbene (NHC) ligands. The NHC ligands were chosen to cover the gamut of commonly used scaffold variations, but in many cases, copper complexes could not be obtained or were unstable. Nevertheless, we identified several complexes that were both stable and catalytically active. Our studies provide guidance and starting scaffolds for any researchers interested in aqueous copper(I) catalysis. A key practical aspect of our findings is that azide-bearing copper-NHC complexes are excellent substrates for the azide-alkyne cycloaddition, which allows late-stage tailoring of the copper complexes.