Ge Shulin, Cao Weidi, Kang Tengfei, Hu Bowen, Zhang Hang, Su Zhishan, Liu Xiaohua, Feng Xiaoming
Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, China.
Angew Chem Int Ed Engl. 2019 Mar 18;58(12):4017-4021. doi: 10.1002/anie.201812842. Epub 2019 Feb 19.
The enantioselective tandem reaction of β,γ-unsaturated α-ketoesters with β-alkynyl ketones was realized by a bimetallic catalytic system of achiral Au salt and chiral N,N'-dioxide-Mg complex. The cycloisomerization of β-alkynyl ketone and asymmetric intermolecular [4+2] cycloaddition with β,γ-unsaturated α-ketoesters subsequently occurred, providing an efficient and straightforward access to chiral multifunctional 6,6-spiroketals in up to 97 % yield, 94 % ee and >19/1 d.r. Besides, a catalytic cycle was proposed based on the results of control experiments.
通过非手性金盐和手性N,N'-二氧化物-镁配合物的双金属催化体系实现了β,γ-不饱和α-酮酯与β-炔基酮的对映选择性串联反应。随后发生了β-炔基酮的环异构化以及与β,γ-不饱和α-酮酯的不对称分子间[4+2]环加成反应，以高达97%的产率、94%的对映体过量值和大于19/1的非对映体比例，高效且直接地合成了手性多功能6,6-螺缩酮。此外，基于对照实验结果提出了一个催化循环。
