Chiral-Zn(NTf<sub>2</sub>)<sub>2</sub>-Complex-Catalyzed Diastereo- and Enantioselective Direct Conjugate Addition of Arylacetonitriles to Alkylidene Malonates
作者:Jingjing Yao、Xiaohua Liu、Peng He、Yin Zhu、Xiangjin Lian、Lili Lin、Xiaoming Feng
DOI:10.1002/chem.201302122
日期:2013.11.25
Chiral N,N′‐dioxide/Zn(NTf2)2 complexes were demonstrated to be highly effective in the direct asymmetric conjugate addition of arylacetonitriles to alkylidene malonates under mild conditions. A wide range of substrates were tolerated to afford their corresponding products in moderate‐to‐good yields with high diastereoselectivities (82:18–>99:1 d.r.) and enantioselectivities (81–99 % ee). The reactions
在温和条件下,手性N,N'-二氧化物/ Zn(NTf 2)2配合物在芳基乙腈直接不对称共轭加成到亚烷基丙二酸酯中非常有效。可以耐受各种底物,以中等到良好的产率提供其相应的产品,具有高非对映选择性(82:18–> 99:1 dr)和对映选择性(81–99%ee)。由于三氟甲磺酸金属的高路易斯酸度和配体促进作用,该反应进行得很好。在N,N-二氧化氮作为布朗斯台德碱也使去质子化过程受益。可以在克级进行催化反应,并保持产率,非对映选择性和对映选择性。包含官能团的产品已准备就绪,可以进行进一步操作。此外,提出了可能的催化模型来解释不对称感应的起源。