m-Disubstituted arenes are utilized in various fields but difficult to be directly and selectively obtained by previous synthetic methods in the case of two electron-donating substituents due to the use of aromatic compounds as the substrates, which causes high environmental burdens through multistep synthesis. Thus, dehydrogenative aromatization from non-aromatic cyclohexenones and nucleophiles to produce m-disubstituted arenes is promising and desired to be developed as the novel process overcoming the intrinsic problems. However, there are no reports on dehydrogenative aromatization for one-step synthesis of m-disubstituted arenes including m-phenylenediamine derivatives despite their utilities such as pharmaceuticals and functional polymers because of the difficult product selectivity control.
Herein, the research team successfully developed the unprecedented selective synthesis of m-phenylenediamine derivatives via dehydrogenative aromatization from cyclohexenones and secondary amines by utilizing the unique dehydrogenation catalysis and cooperative catalysis of a cerium-oxide-supported gold nanoparticle catalyst (Au/CeO2). This reaction is an environmentally friendly one-step m-disubstituted arene synthesis that does not require the isolation and purification of intermediates using O2 in the air as the terminal oxidant. The present catalytic system also enables the synthesis of various new molecules of m-phenylenediamine derivatives, paving the way for the replacement of existing multistep processes with green ones and the efficient creation of new functional materials.
Papers
Journal: Journal of the American Chemical Society
Title: Au-Catalyzed Aerobic Dehydrogenative Aromatization to m-Phenylenediamine Derivatives via Product Selectivity Control
Authors: Heizo Kimura, Takafumi Yatabe*, Kazuya Yamaguchi*
DOI: 10.1021/jacs.4c12043