1565863-80-0Relevant academic research and scientific papers
Synthesis of New Donor-Substituted Biphenyls: Pre-ligands for Highly Luminescent (C^C^D) Gold(III) Pincer Complexes
Feuerstein, Wolfram,Holzer, Christof,Gui, Xin,Neumeier, Lilly,Klopper, Wim,Breher, Frank
supporting information, p. 17156 - 17164 (2020/11/30)
We herein report on new synthetic strategies for the preparation of pyridine and imidazole substituted 2,2’-dihalo biphenyls. These structures are pre-ligands suitable for the preparation of respective stannoles. The latter can successfully be transmetalated to K[AuCl4] forming non-palindromic [(C^C^D)AuIII] pincer complexes featuring a lateral pyridine (D=N) or N-heterocyclic carbene (NHC, D=C’) donor. The latter is the first report on a pincer complex with two formally anionic sp2 and one carbenic carbon donor. The [(C^C^D)AuIII] complexes show intense phosphorescence in solution at room temperature. We discuss the developed multistep strategy and touch upon synthetic challenges. The prepared complexes have been fully characterized including X-ray diffraction analysis. The gold(III) complexes’ photophysical properties have been investigated by absorption and emission spectroscopy as well as quantum chemical calculations on the quasi-relativistic two-component TD-DFT and GW/Bethe–Salpeter level including spin–orbit coupling. Thus, we shed light on the electronic influence of the non-palindromic pincer ligand and reveal non-radiative relaxation pathways of the different ligands employed.
Directed meta-Selective Bromination of Arenes with Ruthenium Catalysts
Yu, Qingzhen,Hu, Le'An,Wang, Yue,Zheng, Shasha,Huang, Jianhui
, p. 15284 - 15288 (2016/01/25)
A Ru-catalyzed direct C?H activation/meta-bromination of arenes bearing pyridyl, pyrimidyl, and pyrazolyl directing groups has been developed. A series of bromo aryl pyridines and pyrimidines have been synthesized, and further coupling reactions have also been demonstrated for a number of representative functionalized arenes. Preliminary mechanistic studies have revealed that this reaction may proceed through radical-mediated bromination when NBS is utilized as the bromine source. This type of transformation has opened up a new direction for the radical non-ipso functionalization of metal with regard to future C?H activation development that would allow the remote functionalization of aromatic systems.
Cu-mediated direct aryl C - H halogenation: A strategy to control mono- and di-selectivity
Du, Zhi-Jun,Gao, Lian-Xun,Lin, Ying-Jie,Han, Fu-She
, p. 123 - 126 (2014/01/23)
A protocol for the copper-mediated direct aryl C - H halogenation is presented. Highly selective mono- and di-halogenations are achieved by using acyl hypohalites, generated in situ from the readily available carboxylic acid and N-halosuccinimides (NXS; X=Br and Cl) as powerful halogenating reagents. The correct choice of carboxylic acid additives and solvents is essential for both high yield and selectivity. Consequently, the use of inexpensive Cu catalyst and the new strategy for the in situ generation of acyl hypohalite halogenating reagents from the readily affordable and easily-to-handle carboxylic acid and NXS (X=Br and Cl) offers advantages for practical application. Copyright
