报道了铜催化下 α,β-不饱和砜的不同官能化。使用铜催化剂、磷酸烯丙酯、双(频哪醇)二硼和LiOMe实现了烯基砜的非对映选择性硼基化烯丙基化。在该方法中,将铜-硼基络合物添加到烯基砜中并随后进行烯丙基取代,使得硼烯丙基化产物具有良好的产率和优异的顺式非对映选择性。相反,更强的碱(KO t -Bu)通过消除磺酰基和硼基基团,进一步促进反应形成( E )-跳过的二烯。
A one-pot regioselective synthetic route to vinyl sulfones from terminal epoxides in aqueous media
作者:Ruchi Chawla、Ritu Kapoor、Atul K. Singh、Lal Dhar S. Yadav
DOI:10.1039/c2gc16664j
日期:——
A highly efficient LiBr catalysed regioselective synthesis of vinyl sulfones from readily available terminal epoxides and sodium sulfinates in a one-pot procedure using water as a reaction medium is reported. The protocol is adorned with several attributes of green chemistry like recycling of the catalyst, atom-economy and an aqueous medium.
towards phosphineoxides and phosphonates has been successfully developed through the desulfonative coupling of various sulfones with secondary phosphineoxides and phosphites. This protocol features simple experimental procedures under mild conditions (i. e., catalyst‐ and oxidant‐free, room temperature and open to air). By doing so, a variety of alkynyl, alkenyl and allyl phosphineoxides or phosphonates
Visible-light-mediated alkylation of 4-alkyl-1,4-dihydropyridines with alkenyl sulfones
作者:Fuyang Yue、Jianyang Dong、Yuxiu Liu、Qingmin Wang
DOI:10.1039/d1ob01806j
日期:——
Herein we report a mild, general protocol for visible-light-mediated alkylation of 4-alkyl-1,4-dihydropyridines with alkenyl sulfones. The protocol permits efficient functionalization of sulfones with a broad range of cyclic and acyclic secondary and tertiary alkyl groups and is scalable to the gram level. Its excellent functional group tolerance and mildness make it suitable for late-stage functionalization
Metal-free, high yielding synthesis of unsymmetrical biaryl, bi(heteroaryl), aryl vinyl, aryl alkyl sulfones via coupling of aryne with sulfinic acid salts
作者:Sravan Kumar Aithagani、Kushalava Reddy Yempalla、Gurunadham Munagala、Ram A. Vishwakarma、Parvinder Pal Singh
DOI:10.1039/c4ra07370c
日期:——
Here, we report a metal-free, high yielding method for the synthesis of unsymmetrical biaryl sulfones via coupling of aryne with sulfinic acid salts. The optimized condition also works efficiently for bi(heteroaryl), arylvinyl and aryl alkyl sulfones. The present method took comparatively shorter reaction times and has good functional group compatibility.
Probing the Evolution of Palladium Species in Pd@MOF Catalysts during the Heck Coupling Reaction: An Operando X-ray Absorption Spectroscopy Study
作者:Ning Yuan、Vlad Pascanu、Zhehao Huang、Alejandro Valiente、Niclas Heidenreich、Sebastian Leubner、A. Ken Inge、Jakob Gaar、Norbert Stock、Ingmar Persson、Belén Martín-Matute、Xiaodong Zou
DOI:10.1021/jacs.8b03505
日期:2018.7.5
mechanism of the Heck C-C coupling reactioncatalyzed by Pd@MOFs has been investigatedusing operando X-ray absorption spectroscopy (XAS) and powder X-ray diffraction (PXRD) combined with transmission electron microscopy (TEM) analysis and nuclear magnetic resonance (1H NMR) kinetic studies. A custom-made reaction cell was used, allowing operando PXRD and XAS data collection using high-energy synchrotron
使用原位 X 射线吸收光谱 (XAS) 和粉末 X 射线衍射 (PXRD) 结合透射电子显微镜 (TEM) 分析和核磁共振 (1H) 研究了由 Pd@MOFs 催化的 Heck CC 偶联反应的机理。 NMR)动力学研究。使用定制的反应池,允许使用高能同步辐射进行操作 PXRD 和 XAS 数据收集。通过结合非原位研究分析 XAS 数据,可以跟踪钯物种从合成状态到失活形式的演变。提出了一种自适应反应机制。发现单核 Pd(II) 配合物是反应开始时的主要活性物质,然后在随后的催化转换中逐渐转变为平均具有 13-20 个 Pd 原子的 Pd 纳米团簇。可用试剂和底物的消耗导致 Cl- 离子与其表面配位,从而导致活性位点中毒。通过了解失活过程,可以调整反应条件并延长催化剂的寿命。