Catalytic Arylation of a CH Bond in Pyridine and Related Six-Membered N-Heteroarenes Using Organozinc Reagents
作者:Isao Hyodo、Mamoru Tobisu、Naoto Chatani
DOI:10.1002/asia.201100971
日期:2012.6
Despite significant advances in the catalytic direct arylation of heteroarenes, the application of this reaction to pyridines has been met with limited success. An oxidative nucleophilic arylation strategy has been developed to overcome this problem. Pyridine, pyrazine, quinolone, and related electron‐deficient N‐heteroarenes can be arylated at the most electrophilic site using the developed nickel‐catalyzed
Sodium Diisopropylamide in Tetrahydrofuran: Selectivities, Rates, and Mechanisms of Arene Metalations
作者:Russell F. Algera、Yun Ma、David B. Collum
DOI:10.1021/jacs.7b08734
日期:2017.10.25
Sodium diisopropylamide (NaDA)-mediated metalations of arenes in tetrahydrofuran (THF)/hexane or THF/Me2NEt solutions are described. A survey of >40 benzenoid- and pyridine-based arenes with a range of substituents demonstrates the efficacy and regioselectivity of metalation. Metalations of activated disubstituted arenes and selected monosubstituted arenes are rapid at −78 °C. Rate studies of 1,3-dimethoxybenzene
描述了在四氢呋喃(THF)/己烷或THF / Me 2 NEt溶液中,二异丙基氨基钠(NaDA)介导的芳烃金属化。对超过40种具有一系列取代基的基于苯并吡啶和吡啶的芳烃的研究表明,其金属化的功效和区域选择性都很高。活化的二取代的芳烃和选定的单取代的芳烃在-78°C时快速金属化。1,3-二甲氧基苯和相关甲氧基化芳烃的速率研究表明,基于单体的原金属具有两个或三个配位的THF配体。苯和具有弱活化基团的单取代芳烃的同位素交换速率研究表明,类似的二溶剂化和三溶剂化的单体基金属化反应。讨论了协同的诱导,消旋,空间和螯合作用。
Selective C–O Bond Reduction and Borylation of Aryl Ethers Catalyzed by a Rhodium–Aluminum Heterobimetallic Complex
We report the catalytic reduction of a C–Obond and the borylation by a rhodium complex bearing an X-type PAlP pincer ligand. We have revealed the reaction mechanism based on the characterization of the reaction intermediate and deuterium-labeling experiments. Notably, this novel catalytic system shows steric-hindrance-dependent chemoselectivity that is distinct from conventional Ni-based catalysts
Efficient Indium-Mediated Dehalogenation of Aromatics in Ionic Liquid Media
作者:Álvaro Cañete、Cristian Salas、Flavia Zacconi
DOI:10.3390/molecules18010398
日期:——
An efficient indium-mediated dehalogenation reaction of haloaromatics and haloheteroaromatics in ionicliquids has been studied. This method is simple and effective in the presence of [bmim]Br. Furthermore, this methodology is environmentally friendly compared with conventional ones.
An increment system for deuterium isotope effects on13C chemical shifts of methylated benzenes
作者:Stefan Berger、Bernd W. K. Diehl
DOI:10.1002/mrc.1260241210
日期:1986.12
The complete series of all possible benzenes bearing one deuterium atom and one to five methyl groups was synthesized. The deuteriumisotopeeffects on the carbon chemicalshifts of the aromatic and aliphatic carbon atoms were measured and shown to obey an empirical increment system. The isotopeeffects over one bond correlate with the C,H spin coupling constants.