(S)-6-Nitroindoline-2-carboxylic acid, a substructure occurring in numerous biologically active natural products, was synthesized with moderate yield (53%) and high enantiomeric excess (>99.5%) starting from the nitration of l-phenylalanine, which is a commercially available chiral pool compound, followed by successively bromination and intramolecular cyclization. The route was carried out in gram quantities and it is suitable for industrial application due to its convenient reaction conditions and low cost.

chiral pool synthesis - (S)-6-nitroindoline-2-carboxylic acid - l-phenylalanine - 2-bromo-4-nitro-l-phenylalanine - intramolecular cyclization

中文翻译：

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从1-苯丙氨酸轻松合成手性池（S）-6-硝基吲哚-2-羧酸

（S）-6-硝基二氢-2-羧酸是存在于许多具有生物活性的天然产物中的子结构，从硝化1-苯丙氨酸开始，合成产率中等（53％），对映体过量高（> 99.5％），它是可商购的手性库化合物，随后依次溴化和分子内环化。该路线以克为单位进行，并且由于其便利的反应条件和低成本而适合工业应用。

手性库合成-（S）-6-硝基吲哚-2-羧酸-1-苯丙氨酸-2-溴-4-硝基-1-苯丙氨酸-分子内环化