Highly efficient synthesis and solid-state characterization of 1,2,4,5-tetrakis(alkyl- and arylamino)benzenes and cyclization to their respective benzobis(imidazolium) salts.
[reaction: see text] New synthetic methodology to a variety of 1,2,4,5-tetraaminobenzenes and their corresponding benzobis(imidazolium) salts has been accomplished. Palladium-catalyzed coupling of various 1,2,4,5-tetrabromo- or 1,2,4,5-tetrachlorobenzenes with aryl- or tert-alkylamines afforded the respective tetrakis(N-substituted)aminobenzenes in excellent yields. This enabled comparative solid-state structural analyses of this elusive class of electron-rich arenes with their oxidized derivatives. The tetraamines were found to undergo formylative cyclization to the corresponding benzobis(imidazolium) salts in good to excellent yields.
Khramov
Dimitri M
DM
Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA.
Boydston
Andrew J
AJ
Bielawski
Christopher W
CW
D001555:Benzene Derivatives / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D018360:Crystallography, X-Ray; D003500:Cyclization; D007093:Imidazoles / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D015394:Molecular Structure; D012492:Salts / Q000138:chemical synthesis / Q000737:chemistry
D001555:Benzene Derivatives; D007093:Imidazoles; D012492:Salts