A Facile Access to Sterically Less Crowded to More Crowded Organo Triselones

摘要

The reaction of 2,4,6-N'-imidazolium(N-alkyl or N-aryl)-mesitylene bromides (alkyl=Me, isopropyl, vinyl, allyl; aryl=2,6- dimethyl-phenyl and 2,6-diiospropyl-phenyl) with six equivalents of selenium powder and potassium carbonate gave corresponding 2,4,6-N'-imidazole(N-alkyl or N-aryl)-selone-mesitylenes in very good yield. These new compounds were characterized by multinuclear (1D and 2D) NMR, FT-IR, UV-vis and single-crystal X-ray diffraction techniques. These trisimidazole selones are the first structurally characterized triselones supported by aryl platform. An interesting geometrical orientation of imidazole selones was observed from the solid-state structures of trisimidazole selones. The orientation of imidazole selones in isopropyl and vinyl trisimidazole selone derivatives are in propeller shape, while methyl, allyl, 2,6-dimethyl-phenyl and 2,6-diiospropyl-phenyl derivatives of trisimidazole selone derivatives are in twisted propeller shape.