Chiral α-hydroxy-β-lactams are key fragments of many bioactive compounds and antibiotics, and the development of efficient synthetic methods for these compounds is of great value. The highly enantioselective dynamic kinetic resolution (DKR) of α-keto-β-lactams was realized via a novel proton shuttling strategy. A wide range of α-keto-β-lactams were reduced efficiently and enantioselectively by Ni-catalyzed asymmetric hydrogenation, providing the corresponding α-hydroxy-β-lactam derivatives with high yields and enantioselectivities (up to 92% yield, up to 94% ee). Deuterium-labelling experiments indicate that phenylphosphinic acid plays a pivotal role in the DKR of α-keto-β-lactams by promoting the enolization process. The synthetic potential of this protocol was demonstrated by its application in the synthesis of a key intermediate of Taxol and (+)-epi-Cytoxazone.

中文翻译：

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质子穿梭使镍催化的DKR催化α-酮基-β-内酰胺的不对称还原

手性α-羟基-β-内酰胺是许多生物活性化合物和抗生素的关键片段，开发有效的合成方法具有重要价值。α-酮-β-内酰胺的高对映选择性动态动力学拆分（DKR）通过一种新颖的质子穿梭策略。Ni催化不对称氢化可有效地和对映选择性地还原各种α-酮-β-内酰胺，从而提供具有高收率和对映选择性的相应α-羟基-β-内酰胺衍生物（最高收率92％，最高收率94％ ee）。氘标记实验表明，苯基次膦酸通过促进烯醇化过程在α-酮-β-内酰胺的DKR中起关键作用。该方案的合成潜力通过其在紫杉酚和（+）- Epi -Cytoxazone关键中间体的合成中的应用得到证明。