Reactivity of an o-indoloquinone to 1- and 2-azadienes.
ABSTRACT The cycloaddition reactions of o-indoloquinone 4 to azadienes are described. With 1-azadiene 2, quinone 4 works as a dienophile to give the directly aromatized cycloadduct 6. In contrast, when 2-azadiene 3 is used, the cycloaddition occurs with CO-4, indicating that this system functions as a heterodienophile.
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ABSTRACT: Oxidation of 2- and 3-hydroxycarbazoles with Frémy's salt gave the corresponding ortho-carbazolequinones. These molecules react as carbodienophiles in Diels-Alder reaction with 1-acetoxy-1,3-butadiene and 1,3-cyclopentadiene to provide the novel benzocarbazolequinone structures 15, 16, 18 and 19.CHEMICAL & PHARMACEUTICAL BULLETIN 10/2004; 52(9):1114-6. DOI:10.1248/cpb.52.1114 · 1.38 Impact Factor