对映选择性[4+2]环化反应用于简洁合成手性二氢咔唑。

Wang Haiyang, Hu Qingdong, Wang Mingxu, Guo Chang

Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China.

iScience. 2020 Feb 21;23(2):100840. doi: 10.1016/j.isci.2020.100840. Epub 2020 Jan 17.

A highly efficient phosphine-catalyzed enantioselective [4 + 2] annulation of allenoates with 3-nitroindoles or 3-nitrobenzothiophenes has been developed. The protocol represents a unique dearomatization-aromatization process to access functionalized dihydrocarbazoles or dihydrodibenzothiophenes with high optical purity (up to 97% ee) under mild reaction conditions. The synthetic utility of the highly enantioselective [4 + 2] annulation enables a concise synthesis of analgesic agent.

已开发出一种高效的膦催化的烯酸酯与3-硝基吲哚或3-硝基苯并噻吩的对映选择性[4 + 2]环化反应。该方法代表了一种独特的去芳构化-芳构化过程，可在温和的反应条件下获得具有高光学纯度（高达97% ee）的官能化二氢咔唑或二氢二苯并噻吩。这种高度对映选择性的[4 + 2]环化反应的合成效用实现了镇痛药的简洁合成。