具有三种氧化态的新型氧化还原系统备受追捧,例如用于氧化还原液流电池应用、选择性还原剂或有机电子产品。在此,我们描述了一种基于多种吡啶盐与卡宾的分子间反应的新型三态氧化还原系统的直接和模块化合成。这些杂化物代表具有定制电化学特性的有机(超级)电子供体,并具有三种稳定的氧化态,可以通过 X 射线衍射等对其进行充分表征。我们详细说明了哪些电子因素要么通过一次电子转移促进获得稳定的自由基,要么有利于 2e 过程。事实上,根据X射线数据,验证了潜在的压缩机制,该机制源于第一次氧化事件中的大结构变形。通过几何锁定这种杂交变化,可以实现潜在的扩展。新一类稳定的有机自由基对空气具有高度持久性,甚至中等稳定性。此外,我们证明了我们的模块化合成方法也适用于利用桥接吡啶盐的非常强的多电子 (4e-) 供体。基于新氧化还原系统的稳定性和可逆性,我们可以通过充放电实验证明使用混合分子作为非水氧化还原液流电池的新型阳
制备了一系列吡啶鎓盐和联吡啶鎓盐,并在亚胺和丹麦谢夫斯基二烯之间的氮杂-狄尔斯-阿尔德反应中评估了它们的催化性能。根据吡啶鎓/联吡啶鎓环的取代基和抗衡离子的性质,证明了两种活化机制。在未取代环的情况下,底物通过涉及亚胺 C 侧芳环的电荷转移而被激活。当在催化剂上引入卤素原子时,活化模式切换到涉及亚胺氮孤对的卤素键。此外,排除了基于氢键和自由基阳离子的替代激活模式。这项工作使我们能够开发出两类催化剂,它们的潜力在各种亚胺与丹麦谢夫斯基二烯的环加成反应中得到了证明。第一个家族由简单的甲基吡啶三氟甲磺酸盐和二辛基联吡啶三氟甲磺酸盐组成。前者仅对带有 a 的亚胺有效发现 C 侧的对甲氧基苯基和后者对于在亚胺的 N 侧和 C 侧带有不同取代基的亚胺是有效的。第二类是基于卤化吡啶鎓盐,它被证明对几乎所有考虑的亚胺都有活性。
Mild Oxidative Conversion of Nitroalkanes into Carbonyl Compounds in Ionic Liquids
作者:Olga Bortolini、Antonio De Nino、Angelo Garofalo、Loredana Maiuolo、Beatrice Russo
DOI:10.1080/00397910903267921
日期:2010.7.27
Basic hydrogen peroxide and sodium perborate were found to be cheap and efficient alternatives for the conversion of primary and secondary nitro to carbonylcompounds (Nef reaction) in ionic liquids.
DONOR-ACCEPTOR NANOHOOP COMPOUNDS AND METHODS OF MAKING AND USING THE SAME
申请人:University of Oregon
公开号:US20160372684A1
公开(公告)日:2016-12-22
Disclosed herein are embodiments of nanostructure compounds that exhibit unique shape configurations, such as nanohoops. The compounds disclosed herein exhibit unique chemical and electrochemical properties that can be tuned and modified to facilitate their use in a variety of different applications.
prepared and tested as simple catalysts of oxidations with hydrogen peroxide, using sulfoxidation as a model reaction. Their catalyticefficiency strongly depends on the type of substituent and is remarkable for derivatives with an electron-withdrawing group, showing reactivity comparable to that of flaviniumsalts which are the prominent organocatalysts for oxygenations. Because of their high stability
制备了一系列的单取代的嘧啶鎓和吡嗪鎓三氟甲磺酸酯和3,5-二取代的吡啶鎓三氟甲磺酸酯,并使用硫氧化作为模型反应,对过氧化氢的简单氧化催化剂进行了测试。它们的催化效率在很大程度上取决于取代基的类型,并且对于具有吸电子基团的衍生物而言是显着的,其反应性与黄酮盐相当,后者是氧合作用的主要有机催化剂。由于它们的高稳定性和良好的可及性,4-(三氟甲基)嘧啶鎓和3,5-二硝基吡啶鎓三氟甲磺酸盐是选择的催化剂,并显示出催化脂肪族和芳香族硫化物氧化为亚砜的作用,定量转化率高,制备产率高,并且具有优异的性能。化学选择性。K R +值(p K R + <5)和较小的负还原电位(E red > -0.5 V)。在催化氧化过程中原位形成的过氧化氢加合物充当底物氧化剂。通过在B3LYP / 6-311 ++ g(d,p)水平上的计算获得的从这些杂环氢过氧化物到硫代苯甲醚的转移的吉布斯自由能表明,它们是比烷基氢过氧化
A predictive model for additions to <i>N</i>-alkyl pyridiniums
作者:Brian J. Knight、Zachary A. Tolchin、Joel M. Smith
DOI:10.1039/d1cc00056j
日期:——
Disclosed in this communication is a thorough study on the dearomative addition of organomagnesium nucleophiles to N-alkyl pyridinium electrophiles. The regiochemical outcomes have observable and predictable trends associated with the substituent patterns on the pyridinium electrophile. Often, the substituent effects can be either additive, giving high selectivities, or ablative, giving competing outcomes
Intramolecular Triarylmethane–Triarylmethylium Complexes with a Naphthalene-1,8-diyl Skeleton: Isolation, Structure, and Reactivities of the CH-Bridged Carbocations
um complexes with a naphthalene-1,8-diyl-type skeleton have been achieved. These bridged cations prefer a C--H localized structure both in solution and in the solid state. The bridging hydrogen undergoes a facile intramolecular 1,5-hydride shift from one carbon to another in solution. The C--H delocalized geometry is suggested to be the transition-state structure of the degeneraterearrangement. Charge-transfer