Palladium-catalyzed three-component tandem reaction of sulfonyl hydrazones, aryl iodides and allenes: highly stereoselective synthesis of (Z)-α-hydroxymethyl allylic sulfones
作者:Yunlei Hou、Qi Shen、Liangyu Zhu、Yufei Han、Yanfang Zhao、Mingze Qin、Ping Gong
DOI:10.1039/c7ra08208h
日期:——
Sulfonyl hydrazones have been identified as an excellent sulfonyl anion surrogate in the base and Pd0-catalyzed three-component tandemreaction with aryl iodides and allenes for the synthesis of functionalized allylic sulfones. By forming a stabilized six-membered palladacycle intermediate, the reaction led to the desired higher substituted allylic sulfones with excellent Z selectivities and high yields
Cu(II)-Catalyzed Aminocyclization of <i>N</i>-Propargyl Hydrazones to Substituted Pyrazolines
作者:Yogesh Brijwashi Sharma、Debosmita Das、Murali Mohan Guru
DOI:10.1021/acs.joc.3c01848
日期:2023.12.1
under open flask conditions via intramolecular C–N bond formation. N-acyl and N-tosyl-substituted pyrazolines have been prepared in moderate to excellent yields. Mechanistic investigations using NMR, high-resolution mass spectrometry (HRMS), and Hammett analyses suggest that the Cu(II) catalyst generally acts as a Lewisacid to form an iminium-ion intermediate via cyclization, which afforded the desired
据报道,在敞口烧瓶条件下,通过分子内 C-N 键形成,铜 (II) 催化从容易获得的N-炔丙基腙合成取代吡唑啉的有效路线。N-酰基和N-甲苯磺酰基取代的吡唑啉已以中等至优异的产率制备。使用核磁共振、高分辨率质谱 (HRMS) 和哈米特分析进行的机理研究表明,Cu(II) 催化剂通常充当路易斯酸,通过环化形成亚胺离子中间体,在水解时提供所需的吡唑啉。利用这种反应方法还合成了一种黄体酮受体拮抗剂。