Chloranil, and the parent benzoquinone, are relatively mild oxidants (dehydrogenation reagents).
A palladium-catalyzed intramolecular amination of alkenes with tosyl-protected amines was achieved under mild reaction conditions in the presence of chloranil to provide versatile dihydropyrrole derivatives with retention of olefin functionalization in good yields.
B. Jiang, F.-F. Meng, Q.-J. Liang, Y.-H. Xu, T.-P. Loh, Org. Lett., 2017, 19, 914-917.
N-Benzyl ketimines undergo [3 + 2] cycloaddition with arylacetylenes in KOtBu/DMSO solution to provide 2,3,5-triarylpyrrolines in good yields. A subsequent in situ oxidation with chloranil or DDQ gives 2,3,5-triaryl-2H-pyrroles in good yields.
I. A. Bidusenko, E. Y. Schmidt, I. A. Ushakov, A. V. Vashchenko, B. A. Trofimov, Org. Lett., 2021, 23, 4121-4126.
An oxidative annulation of o-allylanilines provides 2,4-diarylquinolines in good yields in the presence of chloranil as recyclable oxidant. Furthermore, a one-pot access to 2,4-diarylquinolines from easily available anilines and 1,3-diarylpropenes is described.
D. Cheng, X. Yan, J. Shen, Y. Pu, X. Xu, J. Yan, Synthesis, 2020, 52, 1833-1840.