Herein, we report the stereoselective synthesis of trisubstituted benzoxazino[4,3-b][1,2,5]thiadiazepinone 6,6-dioxides from polymer-supported Fmoc-Ser(tBu)-OH and Fmoc-Thr(tBu)-OH. After the solid-phase synthesis of N-alkylated-N-sulfonylated intermediates using various 2-nitrobenzenesulfonyl chlorides and bromoketones, the target compounds were obtained via trifluoroacetic acid (TFA)-mediated cleavage from the resin, followed by cyclization of the diazepinone scaffold. Except for the threonine-based intermediates, the inclusion of triethylsilane (TES) in the cleavage cocktail yielded a specific configuration of the newly formed C³ chiral center. The final cyclization resulted in minor or no inversion of the C^12a stereocenter configuration.

中文翻译：

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聚合物负载的立体选择性合成苯并恶嗪[4,3- b ] [1,2,5]噻二氮杂醌6,6-二氧化物

本文中，我们报道了由聚合物负载的Fmoc-Ser（t Bu）-OH和Fmoc-Thr（t Bu ）立体选择性合成三取代的苯并恶嗪[4,3- b ] [1,2,5]噻二氮杂醌6,6-二氧化物）-哦。在使用各种2-硝基苯磺酰氯和溴酮进行固相合成N-烷基化-N-磺酰化中间体之后，通过三氟乙酸（TFA）介导的树脂裂解获得目标化合物，然后环化二氮杂酮骨架。除基于苏氨酸的中间体外，裂解混合物中还包含三乙基硅烷（TES），可产生新形成的C ³的特定构型手性中心。最终环化导致C ^12a立体中心构型发生极少或没有反转。