Asymmetric Construction of Spiropyrazolone Skeletons <i>via</i>
Amine-Catalyzed [3+3] Annulation
作者:Hai-Jun Leng、Qing-Zhu Li、Rong Zeng、Qing-Song Dai、Hong-Ping Zhu、Yue Liu、Wei Huang、Bo Han、Jun-Long Li
DOI:10.1002/adsc.201701035
日期:2018.1.17
Here we report a secondary amine‐catalyzed, highly enantioselective [3+3] cyclization reaction of α‐alkylidene pyrazolinones and α,β‐unsaturated aldehydes, which facilely delivers a variety of enantioenriched spiropyrazolones showing structural and stereochemical complexity. The reaction uses an iminium ion activation strategy to activate both the β‐ and ipso‐positions of the enals as dielectrophilic
在这里,我们报告了仲胺催化的α-亚烷基吡唑啉酮与α,β-不饱和醛的高度对映选择性[3 + 3]环化反应,该反应可轻松提供各种对映体富集的螺并吡唑并酮,它们显示出结构和立体化学的复杂性。该反应使用亚铵离子激活策略激活两个β-和本位的enals作为dielectrophilic站点的位上。各种各样的底物都与这种温和的反应系统兼容。