Liu Yingying, Ye Ling, Shi Zhichuan, Yang Xuejun, Zhao Zhigang, Li Xuefeng
College of Chemistry and Environment Protection Engineering, Southwest Minzu University, Chengdu, China.
Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China.
Chirality. 2018 Dec;30(12):1287-1303. doi: 10.1002/chir.23023. Epub 2018 Oct 4.
A highly enantioselective (91- > 99% ee) Michael addition of α-nitroacetate to α,β-unsaturated pyrazolamide was developed in the presence of a bifunctional squaramide. Satisfactory isolated yields (42%-99%) have been achieved with a wide range of α,β-unsaturated pyrazolamides, albeit acceptor of this type displayed poor reactivity in the precedent reports. The adducts resulting from this protocol are useful synthetic intermediates for further synthetic modification.
在双功能方酰胺存在的条件下，开发了一种α-硝基乙酸酯与α,β-不饱和吡唑酰胺的高对映选择性（对映体过量值从91%提高到99%）迈克尔加成反应。对于多种α,β-不饱和吡唑酰胺，都获得了令人满意的分离产率（42%-99%），尽管这类受体在之前的报道中显示出较差的反应活性。该反应方案得到的加合物是用于进一步合成修饰的有用合成中间体。
