Copper complexes for the chemoselective N -arylation of arylamines and sulfanilamides via Chan-Evans-Lam cross-coupling.
Selvam RajuMohsen TeimouriBhupendra AdhikariBruno DonnadieuSean L StokesJoseph P EmersonPublished in: Dalton transactions (Cambridge, England : 2003) (2023)
Copper(II) complexes with tridentate NNN -ligands were utilized for Chan-Evans-Lam (CEL) cross-coupling reactions to enable the N -arylation of multifarious N -nucleophiles through the activation of aryl boronic acids. A condition-specific methodology was developed to chemoselectively target the amine versus sulfonamide N -arylation of 4-aminobenzenesulfonamide using new catalysts. Two different pyridine-based ligands and corresponding copper(II) complexes were characterized using 1 H and 13 C-NMR, FTIR, and UV-vis spectroscopy, HRMS, single-crystal X-ray diffraction, and cyclic voltammetry. Solvent and base-controlled cross-coupling reactions were observed, which led to the optimization of selective conditions for targeted C-N bond formation of sulfanilamides. Beyond the chemoselective processes reported here, a breadth of N -nucleophiles including sulfanilamides and arylamines were screened for arylation by this CEL catalyst.