Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing 100084, China.
Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China.
Science. 2022 Feb 25;375(6583):869-874. doi: 10.1126/science.abl4922. Epub 2022 Feb 24.
Catalytic deracemization of α-branched aldehydes is a direct strategy to construct enantiopure α-tertiary carbonyls, which are essential to pharmaceutical applications. Here, we report a photochemical / isomerization strategy for the deracemization of α-branched aldehydes by using simple aminocatalysts and readily available photosensitizers. A variety of racemic α-branched aldehydes could be directly transformed into either enantiomer with high selectivity. Rapid photodynamic / isomerization and highly stereospecific iminium/enamine tautomerization are two key factors that underlie the enantioenrichment. This study presents a distinctive photochemical / isomerization strategy for externally tuning enamine catalysis.
手性α-支链醛的催化外消旋化是构建手性α-叔碳羰基化合物的直接策略，这些化合物在手性药物应用中至关重要。在这里，我们报告了一种通过使用简单的氨基催化剂和易得的光敏剂进行光化学/异构化策略来实现α-支链醛外消旋化的方法。各种外消旋α-支链醛可以通过高选择性直接转化为任一对映体。快速光动力/异构化和高度立体特异性的亚胺/烯胺互变异构是导致对映体富集的两个关键因素。这项研究提出了一种独特的光化学/异构化策略，用于外部调节烯胺催化。
