Substrate-Controlled Domino Reactions of Crotonate-Derived Sulfur Ylides: Synthesis of Benzothiophene Derivatives

Substrate-controlled domino reactions between thioaurones or their analogues and crotonate-derived sulfur ylides were developed and produced a broad spectrum of benzothiophene-fused pyran derivatives, substituted chromene derivatives. In these reactions, crotonate-derived sulfur ylides acting as two-carbon synthons (α and β carbons or β and γ carbons) in annulation reactions are reported for the first time. These investigations nicely complement and expand previously studied reactions of crotonate-derived sulfur ylides. In addition, reaction mechanisms for these domino reactions are proposed, one of which is supported by DFT calculations.本研究开发了底物调控的硫代噢哢（thioaurones）及其类似物与巴豆酸酯衍生的硫叶立德（crotonate-derived sulfur ylides）之间的多米诺反应，该反应可制备得到一系列苯并噻吩并吡喃衍生物与取代色烯衍生物。本研究首次报道，巴豆酸酯衍生的硫叶立德可作为环化反应中的双碳合成子（α碳与β碳，或β碳与γ碳）。该研究成果很好地补充并拓展了此前关于巴豆酸酯衍生硫叶立德的反应研究。此外，本研究还提出了该类多米诺反应的反应机理，其中一种机理得到了密度泛函理论（DFT）计算的支持。