prior formation of N-activated pyridines, organometallic reagents, and extra oxidation operation for the construction of a C–C bond at the C4-position of the pyridines in previous methods are not required. The corresponding mechanism and the key roles of the organoborane were elaborated by the combination of H/D scrambling experiments, 11B NMR studies, intermediate trapping experiments and computational
第一NaBEt 3 H-催化分子间吡啶Chichibabin型烷基化和其与烯烃作为潜亲核试剂衍生物呈现BET的协助3,以及一系列支链C4烷基化吡啶,即使高度拥塞全碳季中心含-三芳基甲烷可以以区域特异性方式获得。因此,传统上依赖于高成本和低可用性的过渡金属催化剂,先形成N活化的吡啶,有机金属试剂和在以前方法中不需要额外的氧化操作来在吡啶的C4位上构建C–C键。H / D加扰实验,11 B NMR研究,中间捕获实验和计算研究相结合详细阐述了有机硼烷的相应机理和关键作用。这种直接的,机械上独特的有机催化技术不仅为经典的但仍未得到很好开发的奇奇巴宾型反应打开一扇新门,而且为开发新型C–C键形成方法建立了新平台。
Photoinduced direct 4-pyridination of C(sp3)–H Bonds
作者:Tamaki Hoshikawa、Masayuki Inoue
DOI:10.1039/c3sc51080h
日期:——
Direct substitution of hydrogen in C(sp3)âH bonds by 4-pyridine was achieved by employing benzophenone and 4-cyanopyridine in aqueous acetonitrile under photo-irradiating conditions. This simple and mild 4-pyridination proceeds in a highly chemoselective manner especially at benzylic C(sp3)âH bonds without affecting polar functional groups, and enables intermolecular formation of sterically hindered bonds between alkylaromatics and 4-pyridine. The present methodology thus serves as a powerful tool for construction of biologically active and functional molecules with 4-pyridine substructures.
Toulate ester for use as reactive and non-reactive diluent in polymer applications
申请人:McAdams Araullo Carina
公开号:US20060223925A1
公开(公告)日:2006-10-05
This invention relates to toluate ester compositions and their use as solvent, plasticizers, extender and/or diluents in binder formulations, a method of producing such ester compositions, as well as polymer compositions containing such liquid ester compositions. The method of making toluate based esters by reacting methyl-p-toluate with ethylene glycol, diethylene or triethylene glycol, butanediol, etc. More particularly, this invention relates to the mono-or di-ester of methyl toluic acid with a diol containing 2 to 6 carbon atoms that are low viscosity liquids at 25° C. The most common polymer that employs plasticizer is polyvinyl chloride (PVC). Typical amounts of plasticizer in PVC are from about 3 wt. % to about 50 wt. %. Phenolic resins generally require solvents, diluents and/or extenders that reduce the volatility and viscosity of the resin, especially when it is used in building and automotive products. Typical amounts of solvent are from about 5 wt. % to about 65 wt. %.
Nickel-catalysed para-CH activation of pyridine with switchable regioselective hydroheteroarylation of allylarenes
作者:Wei-Chih Lee、Chien-Hung Chen、Cheng-Yuan Liu、Ming-Shiuan Yu、Yung-Huei Lin、Tiow-Gan Ong
DOI:10.1039/c5cc07455j
日期:——
para-CH activation of pyridine with allylbenzene is described by Ni/Al cooperative catalysis to achieve branch and linear selectivity.
使用Ni/Al协同催化描述了烯丙基苯与吡啶的para-CH活化,以实现支链和线性选择性。
Lewis Acid-Catalyzed Selective Reductive Decarboxylative Pyridylation of <i>N</i>-Hydroxyphthalimide Esters: Synthesis of Congested Pyridine-Substituted Quaternary Carbons
作者:Liuzhou Gao、Guoqiang Wang、Jia Cao、Hui Chen、Yuming Gu、Xueting Liu、Xu Cheng、Jing Ma、Shuhua Li
DOI:10.1021/acscatal.9b03798
日期:2019.11.1
practical and efficient Lewis acid-catalyzed radical–radical coupling reaction of N-hydroxyphthalimide esters and 4-cyanopyridines with inexpensive bis(pinacolato)diboron as reductant has been developed. With ZnCl2 as the catalyst, a wide range of quaternary 4-substituted pyridines, including highly congested diarylmethyl and triarylmethyl substituents, could be selectively obtained in moderate to good