Abstract

Novel organocatalysts derived from (R)- and (S)-proline and incorporating a chiral phosphoramide fragment were rationally designed and subsequently synthesized. These chiral compounds catalyze the enantioselective aldol addition reaction of cyclohexanone to prochiral isatins in the presence of water. These observations are particularly relevant since reports of asymmetric aldol reactions between cyclohexanone­ and isatins catalyzed by chiral secondary amines remain scarce, with primary amines being the most studied and successful catalysts. The present report includes a thorough evaluation of the new bifunctional catalysts that actually give rise to either enantiomer of the chiral product by proper selection of the configuration of the proline moiety.

Novel organocatalysts derived from (R)- and (S)-proline and incorporating a chiral phosphoramide fragment were rationally designed and subsequently synthesized. These chiral compounds catalyze the enantioselective aldol addition reaction of cyclohexanone to prochiral isatins in the presence of water. These observations are particularly relevant since reports of asymmetric aldol reactions between cyclohexanone­ and isatins catalyzed by chiral secondary amines remain scarce, with primary amines being the most studied and successful catalysts. The present report includes a thorough evaluation of the new bifunctional catalysts that actually give rise to either enantiomer of the chiral product by proper selection of the configuration of the proline moiety.

中文翻译：

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（R）-和（S）-脯氨酸衍生的手性磷酰胺作为有机催化剂，在水存在下，靛红与环己酮的对映体羟醛缩合反应

摘要

合理设计并合成了衍生自（R）-和（S）-脯氨酸并结合了手性磷酰胺片段的新型有机催化剂。这些手性化合物在水的存在下催化环己酮与前手性靛红的对映选择性羟醛加成反应。由于手性仲胺催化的环己酮和靛红之间不对称醛醇反应的报道仍然很少，伯胺是研究最多和最成功的催化剂，因此这些观察结果尤为重要。本报告包括新的双官能催化剂，实际上由脯氨酸部分的配置的适当选择产生的手性产物的对映体任一的全面评估。

合理设计并合成了衍生自（R）-和（S）-脯氨酸并结合了手性磷酰胺片段的新型有机催化剂。这些手性化合物在水的存在下催化环己酮与前手性靛红的对映选择性羟醛加成反应。由于手性仲胺催化的环己酮和靛红之间不对称醛醇反应的报道仍然很少，伯胺是研究最多和最成功的催化剂，因此这些观察结果尤为重要。本报告包括新的双官能催化剂，实际上由脯氨酸部分的配置的适当选择产生的手性产物的对映体任一的全面评估。