Mechanistic Studies of the Hydroamination of Norbornene with Electrophilic Platinum Complexes: The Role of Proton Transfer
作者:Jennifer L. McBee、Alexis T. Bell、T. Don Tilley
DOI:10.1021/ja8030104
日期:2008.12.10
studies do not favor an olefin coordination mechanism but are instead consistent with a mechanism involving sulfonamide coordination and generation of an acidic proton that is transferred to the norbornene. It is postulated that the resulting norbornyl cation is then attacked by free sulfonamide, and loss of proton from this adduct completes the hydroamination. The platinum-sulfonamide complex readily
addition of sulfonamides and carboxamides to simple alkenes proceeded smoothly using a proton-exchanged montmorillonite catalyst. The spent catalyst was recovered easily from the reaction mixture and was reusable at least five times without any loss of activity. The unique acidity of the proton-exchanged montmorillonite (H-mont) catalyst was found to be applicable to additional reactions: substitution of hydroxyl
Synthesis and biological evaluation of <i>N</i>-alkyl sulfonamides derived from polycyclic hydrocarbon scaffolds using a nitrogen-centered radical approach
作者:Megan D. Hopkins、Ryan C. Witt、Ann Marie E. Flusche、John E. Philo、Garett L. Ozmer、Gordon H. Purser、Robert J. Sheaff、Angus A. Lamar
DOI:10.1039/d2ob01291j
日期:——
serves as reagent for aminosulfonation using pre-formed imidoiodinane as N-source. An investigation of the reaction mechanism was performed to implicate a process involving a N-centered radical. An additional method for sulfonamide installation is described that involves the use of commercially available reagents and operationally convenient conditions. Using the new synthetic methods, 22 compounds
多环烃 (PH) 作为药物化学中的亲脂性支架提供了有趣的潜力,但目前受限于可预测的 PH 单元修饰的合成工具的可用性。在此,我们报告了将磺胺装置安装到 PH 核心的新方法的开发。在第一种方法中,黄原酸酯用作氨基磺化试剂,使用预先形成的亚氨基碘烷作为 N 源。对反应机理进行了研究,以暗示涉及 N 中心自由基的过程。描述了另一种磺胺类药物安装方法,该方法涉及使用市售试剂和操作方便的条件。使用新的合成方法,制备了 22 种化合物,并筛选了针对 6 种哺乳动物细胞系以及革兰氏阳性和革兰氏阴性菌株的生物活性。生存力测定的结果已鉴定出比其他已知抗癌剂(如 indisulam 和 ABT-751)表现出更高效力的化合物。此外,合成化合物的物理化学和药物相似性已通过实验确定,并使用计算机预测工具。对磺胺插入 PH 核心的初步探索已经产生了许多值得进一步开发以生产具有治疗价值的分子的化合物。
The hydroamination of alkenes with sulfonamides catalyzed by the recyclable silica gel supported triflic acid
作者:Pei Nian Liu、Fei Xia、Zheng Le Zhao、Qing Wei Wang、Yu Jie Ren
DOI:10.1016/j.tetlet.2011.09.025
日期:2011.11
The vast applications of triflic acid (TfOH) in catalysis are severely limited by its corrosive and fuming properties. Immobilization of TfOH on silica gel well solves these problems and affords efficient recovery and reusability of TfOH. Two types of supported TfOH, the prepared silica gel supported TfOH and the in situ silica gel adsorbed TfOH, both exhibit good catalytic activity and reusability in the hydroamination of alkene with sulfonamide. The in situ silica gel adsorbed catalyst has been used for 5 runs with maintained reactivities and yields, which are superior to the performance of the prepared silica gel supported TfOH. For a series of alkenes and various sulfonamides, the heterogeneous hydroamination reactions catalyzed by both types of silica gel supported TfOH to afford similar moderate to excellent yields. (C) 2011 Elsevier Ltd. All rights reserved.