Visible-light-mediated photocatalytic sequential N-arylation: an eco-friendly synthetic route to unsymmetrical diarylamines and the imatinib drug

A sustainable protocol for the construction of unsymmetrical diarylamines via a photoredox-mediated dual catalytic copper/ruthenium system has been established. This approach provides easy access to medicinally relevant amines through the sequential arylation of ammonia by utilizing various (hetero)aryl bromides as coupling partners. The resulting in situ generated mono-arylated amines can directly participate in a copper-mediated cross-coupling with aryl boronic acids. Imatinib, a tyrosine kinase inhibitor, is synthesized employing this strategy in an eco-friendly manner.