- A "green" route to perylene dyes: Direct coupling reactions of 1,8-naphthalimide and related compounds under mild conditions using a "new" base complex reagent, t-BuOK/DBN
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The direct coupling reactions of 1,8-naphthalimide compounds efficiently occurred at 130 or 170 °C without the intervention of the leuco form dyes in the presence of base complex reagent, t-BuOK/1,5-diazabicyclo[4.3.0]non-5-ene (DBN), to give the corresponding perylene dyes in good yields with >95% purities. A possible mechanistic speculation for these oxidative coupling reactions is briefly discussed.
- Sakamoto,Pac
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- ELECTRONIC STRUCTURE OF ? SYSTEMS. XI. RADICAL ANIONS OF BENZANTHRONE AND ITS DERIVATIVES AND THEIR ROLE IN CONDENSATION REACTIONS IN THE PRESENCE OF STRONG BASES
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It is shown, with the help of ESR spectroscopy, that benzanthrone, its 3-bromo- and 3-nitro derivatives, 1-benzoylnaphthalene, 1,5-dibenzoylnaphthalene, and dibenzo-pyrene-7,14-quinone, form radical anions when treated with alcoholic alkali solutions.Benzanthrone and its derivatives and analogs react in the presence of strong bases exactly according to the distribution of unpaired electrons on their LUMOs: at C atoms of the hydrocarbon fragment in cyclic compounds and at C atoms of carbonyl groups in acyclic compounds.Radical anions of benzanthrone dimerize at the position of maximal spin density with the formation of 4,4'-bibenzanthronyl.Radical anions of 3-bromobenzanthrone and 3-nitrobenzanthrone are also dimerized at the position of maximal spin density, i.e., at position 3, with the elimination of the substituent and the formation of isoviolanthrone and ethoxyviolanthrone B, respectively, as final products.The products resulting from the transformation in alcoholic alkali of the acyclic analogs of benzanthrone, i.e., 1-benzoylnaphthalene and 1,5-benzoylnaphthalene, are the respective hydroxy derivatives.
- Traven', V. F.,Safronov, A. I.,Makarov, I. G.,Kazakova, V. M.,Chibisova, T. A.
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p. 1709 - 1717
(2007/10/02)
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