A simple photocatalytic method was developed for the synthesis of unsymmetrical 1,2-diamines by the unprecedented reductive coupling of N-benzylidene-[1,1'-biphenyl]-2-amines with an aliphatic amine. The presence of phenyl substituent in the aniline moiety of the substrate was critical for the reactivity. The reaction proceeded via radical-radical cross-coupling of a-amino radicals generated by proton-coupled single-electron transfer in the presence of an Ir-photocatalyst. On the other hand, symmetrical 1,2-diamines were selectively produced from the same starting materials by judicious choice of the reaction conditions, showcasing the distinct reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines. The developed method can be employed for the synthesis of various bulky vicinal diamines, which are potential ligands in stereoselective synthesis.
Keywords: photocatalysis; imine; 1,2-diamine; visible light; diversity
When a peer-reviewed version of this preprint is available in the Beilstein Journals, this information will be updated in the information box above. If no peer-reviewed version is available, please cite this preprint using the following information:
Tambe, S.; Min, K. H.; Iqbal, N.; Cho, E. J. Beilstein Arch. 2020, 202035. doi:10.3762/bxiv.2020.35.v1
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