Substituent effect of diimino-palladium (II) pincer complexes on the catalysis of Sonogashira coupling reaction
摘要:
Three NCN diimine ligands 4-6 were synthesized after condensation of isophthalaldehydes 1-3 and ani-lines. Treatment of 4-6 with Pd-2(dba)(3) in toluene resulted in the corresponding Pd-II-NCN-Bu-t (7), Pd-II-NCN-H (8) and Pd-II-NCN-NO2 (9) pincer complexes, respectively with high yields. Palladium pincers 7-9 and their precursors 4-6 were fully characterized by elemental analysis, IR, H-1 NMR and C-13 NMR spectroscopy. The molecular structures of 7b and 9b were also determined by X-ray single crystal diffraction. Sonogashira coupling of phenyl acetylene and 3-nitrobenzene catalyzed by 7-9 show that 9 exhibits the highest catalytic activity, suggesting that the electron withdrawing groups at the position-4 of palladium atom in palladium pincers will enhance their catalytic activity. (C) 2015 Elsevier Ltd. All rights reserved.
Azatriseptanes: Strained Framework Analogs of [7,7,7]Circulenes
作者:Kai Zhang、Philip A. Hope、Mélissa El Bitar Nehme、Anthony Linden、Bernhard Spingler、Michel Rickhaus
DOI:10.1002/chem.202203954
日期:2023.3.7
A strain on the properties: A [7,7,7]circulene analog, azatriseptane, has been synthesized, and its highly strained structure confirmed by X-ray crystallography and computational studies. The distortion of the typical propeller-like conformation that is observed for triarylamine significantly affects the π-electronics as well as the inherent self-assembly properties of these bridged systems.
对特性的应变:合成了 [7,7,7] 环烯类似物氮杂七烷,其高度应变结构已通过 X 射线晶体学和计算研究得到证实。对于三芳基胺观察到的典型螺旋桨状构象的变形会显着影响 π 电子学以及这些桥接系统的固有自组装特性。