Huang Gaochao, Yin Zengsheng, Zhang Xingang
Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032 (P.R. China).
Chemistry. 2013 Sep 2;19(36):11992-8. doi: 10.1002/chem.201301479. Epub 2013 Jul 15.
A general and efficient method for the highly enantioselective alkynylation of ketoimines through a zinc/1,1'-bi-2-naphthol (BINOL)-catalyzed process has been developed. A variety of ketoimines, including α-fluoroalkyl α-imine esters, α-aryl α-imine esters, and trifluoromethyl aryl ketoimines, are applicable and provide their corresponding quaternary propargyl amines in excellent yields with high ee values (up to 99 % ee). Both the steric and electronic effects of substituents at the 3,3' positions of BINOL are critical for the reaction efficiency and enantioselectivity. To demonstrate the usefulness of the method, (R)-α-CF3 α-proline has been prepared in a highly efficient manner. The notable features of this protocol are its broad substrate scope, high reaction efficiency (up to 99 %) and enantioselectivity (up to 99 % ee), low catalyst loading (5 mol % of BINOL derivative), and mild reaction conditions.
已开发出一种通过锌/1,1'-联二萘酚（BINOL）催化过程实现酮亚胺高度对映选择性炔基化的通用且高效的方法。多种酮亚胺，包括α-氟烷基α-亚胺酯、α-芳基α-亚胺酯和三氟甲基芳基酮亚胺，都适用，并能以优异的产率和高对映体过量值（高达99% ee）提供其相应的季炔丙基胺。BINOL 3,3'位取代基的空间和电子效应对于反应效率和对映选择性都至关重要。为证明该方法的实用性，已以高效方式制备了(R)-α-CF3 α-脯氨酸。该方案的显著特点是底物范围广、反应效率高（高达99%）和对映选择性高（高达99% ee）、催化剂负载量低（5 mol%的BINOL衍生物）以及反应条件温和。
