State Key Laboratory of Structural Chemistry, and Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, University of Chinese Academy of Sciences, Fuzhou 350100, China.
Org Biomol Chem. 2019 Feb 20;17(8):2169-2173. doi: 10.1039/c8ob02468e.
Chiral β-ketoesters bearing fully substituted carbon centers are important building blocks in organic synthesis. Mono-substituted ketoesters have been widely used to synthesize the above compounds through asymmetric additions or substitutions. The limitations of these protocols mainly exist in the substrate scopes, and α-methyl or α-fluoro-substituted β-ketoesters or acetyl acetates are frequently used owing to their relatively higher reactivity. To break through this limitation, we employed N-heterocyclic carbene-catalyzed kinetic resolution to achieve the access to enantioenriched β-ketoesters with quaternary stereocenters. Sterically more bulky groups such as benzyl, allyl, phenyl and cyclopropyl groups are all tolerated using this method.
手性β-酮酯带有完全取代的碳中心，是有机合成中的重要构建块。单取代的酮酯已广泛用于通过不对称加成或取代来合成上述化合物。这些方案的局限性主要存在于底物范围，由于α-甲基或α-氟取代的β-酮酯或乙酰乙酸酯具有较高的反应性，因此经常使用。为了突破这一限制，我们采用了 N-杂环卡宾催化的动力学拆分，以获得具有季立体中心的对映体富集的β-酮酯。该方法可耐受较大体积的取代基，如苄基、烯丙基、苯基和环丙基。
