Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, China.
Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China.
Angew Chem Int Ed Engl. 2016 May 10;55(20):6075-8. doi: 10.1002/anie.201601701. Epub 2016 Apr 8.
A highly efficient asymmetric cascade reaction between keto esters and alkynyl alcohols and amides is reported. The success of the reaction was attributed to the combination of chiral Lewis acid N,N'-dioxide nickel(II) catalysis with achiral π-acid gold(I) catalysis working as an asymmetric relay catalytic system. The corresponding spiroketals and spiroaminals were synthesized in up to 99 % yield, 19:1 d.r., and more than 99 % ee under mild reaction conditions. Control experiments suggest that the N,N'-dioxide ligand was essential for the formation of the spiro products.
报告了一种酮酯和炔醇及酰胺之间高效的不对称级联反应。反应的成功归因于手性路易斯酸 N,N'-二氧化氮镍(II)催化与非手性π-酸金(I)催化相结合，作为不对称接力催化体系发挥作用。在温和的反应条件下，相应的螺环缩酮和螺环亚胺以高达 99%的产率、19:1 的 d.r. 和超过 99%的 ee 合成。控制实验表明，N,N'-二氧化氮配体对于螺产物的形成是必不可少的。
