The first regioselective [4 ​+ ​2] annulation reactions of quinone monoacetals with isothiocyanates and NaS have been accomplished. This convenient and novel protocol involves the synthesis of valuable bridged thiazine-2-thione and thiazole-2-thiones through DBU-promoted at room temperature. Mechanism study reveals the dearomative transformation possibly undergoes a radical cascade reaction on the structure of quinone monoacetals to an efficient synthesis of a broad range of thione-containing heterocyclic compounds with broad tolerance in moderate to excellent yields. Moreover, the reported procedure can be easily applied to a 1g scale.

中文翻译：

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在温和条件下通过 DBU 促进醌单缩醛区域选择性成环合成桥联双环噻嗪-2-硫酮和噻唑-2-硫酮

醌单缩醛与异硫氰酸酯和 NaS 的第一个区域选择性 [4 + 2] 成环反应已经完成。这种方便而新颖的方案涉及在室温下通过 DBU 促进合成有价值的桥联噻嗪-2-硫酮和噻唑-2-硫酮。机理研究表明，脱芳香转化可能在醌单缩醛结构上经历自由基级联反应，从而有效合成多种含硫酮杂环化合物，这些化合物具有广泛的耐受性，产率中等至优异。此外，所报道的程序可以很容易地应用于1g规模。