Access to Ring-Fused Homo- and Heteroaromatic Derivatives via an Initial Ring-Opening of 3-Nitro-4-(phenylsulfonyl)thiophene<sup>1</sup>
作者:Lara Bianchi、Carlo Dell'Erba、Massimo Maccagno、Angelo Mugnoli、Marino Novi、Giovanni Petrillo、Fernando Sancassan、Cinzia Tavani
DOI:10.1021/jo034264q
日期:2003.6.1
in EtOH] is revealed to be an excellent precursor of nitro(phenylsulfonyl) derivatives of ring-fused aromatic (naphthalene, phenanthrene) or heteroaromatic (benzothiophene) compounds whose substitution pattern cannot be easily achieved by conventional methods. The key step is represented by a thermal electrocyclic rearrangement of (E,E)-1-aryl-4-methylsulfonyl-2-nitro-3-phenylsulfonyl-1,3-butadienes
在整个开环/成环方案中,(E,E)-4-甲硫基-2-硝基-3-苯基磺酰基-1-吡咯烷酮-1,3-丁二烯(7)[源自于具有吡咯烷和硝酸银的EtOH中的3-硝基-4-(苯基磺酰基)噻吩(6)是环稠合的芳族(萘,菲)或杂芳族(苯并噻吩)化合物的硝基(苯基磺酰基)衍生物的极佳前体用常规方法不易实现其取代模式。(E,E)-1-芳基-4-甲基磺酰基-2-硝基-3-苯基磺酰基-1,3-丁二烯(9)的热电重排是关键步骤,这要归功于适当的几何和电子因素,发生在前所未有的温和条件下,随后发生不可逆转的变化,