Synthesis and characterization of N-(2-pyridyl)benzamide-based nickel complexes and their activity for ethylene oligomerization
作者:Wen-Hua Sun、Wen Zhang、Tielong Gao、Xiubo Tang、Liyi Chen、Yan Li、Xianglin Jin
DOI:10.1016/j.jorganchem.2003.12.022
日期:2004.3
A series of N-(2-pyridyl)benzamides (1)-(11) and their nickel complexes, [N-(2-pyridyl)benzamide]dinickel(II) di-mu-bromide dibromide (12)-(16) and (aryl)[N-(2-pyridyl)benzamido](triphenylphosphine)nickel(II) (17)-(24), were synthesized and characterized. The single-crystal X-ray analysis revealed that 12 and 14 are binuclear nickel complexes bridged by bromine atoms and each nickel atom adopts a distorted trigonal bipyramidal geometry. The key feature of the complexes 17, 19 and 23 is each has a six-membered nickel chelate ring including a deprotonated secondary nitrogen atom and an O-donor atom. The nickel complexes show moderate to high catalytic activity for ethylene oligomerization with methylaluminoxane (MAO) as cocatalyst. The activity of 12-16/MAO systems is up to 3.3 x 10(4) g mol(-1) h(-1) whereas for 17-24/MAO systems it is up to 4.94 x 10(5) g mol(-1) atm(-1) h(-1). The influence of Al/Ni molar ratio, reaction temperature, reaction period and PPh3/Ni molar ratio on catalytic activity was investigated. (C) 2004 Elsevier B.V. All rights reserved.
Ru(II)-Catalyzed Oxidative Olefination of Benzamides: Switchable Aza-Michael and Aza-Wacker Reaction for Synthesis of Isoindolinones
作者:Manoj Kumar、Shalini Verma、Akhilesh K. Verma
DOI:10.1021/acs.orglett.0c01237
日期:2020.6.19
Selective tandem oxidative C–H olefination–aza-Michael/aza-Wacker reaction of N-arylbenzamides is achieved by fine-tuning between base and additive to access valuable 3-oxoisoindolinyls and 3-oxoisoindolinylidenes, respectively. Careful optimization and control experiments provides a guiding principle in the design of a proposed catalytic cycle. The copper–iminium complex acting as a precursor for