Deng Xiaohu, Mani Neelakandha S
Johnson & Johnson Pharmaceutical Research & Development, L.L.C., 3210 Merryfield Row, San Diego, California 92121, USA.
J Org Chem. 2008 Mar 21;73(6):2412-5. doi: 10.1021/jo7026195. Epub 2008 Feb 16.
Two general protocols are developed for the regioselective synthesis of 1,3,5-tri- and 1,3,4,5-tetrasubstituted pyrazoles by the reaction of electron-deficient N-arylhydrazones with nitroolefins. Studies on the stereochemistry of the key pyrazolidine intermediate suggest a stepwise cycloaddition mechanism.
通过缺电子的N-芳基腙与硝基烯烃的反应,开发了两种用于区域选择性合成1,3,5-三取代和1,3,4,5-四取代吡唑的通用方案。对关键吡唑烷中间体立体化学的研究表明了一种逐步环加成机理。