41464-83-9Relevant articles and documents
Mechanosynthesis of N-methyl imines using recyclable imidazole-based acid-scavenger: In situ formed ionic liquid as catalyst and dehydrating agent
Khaligh, Nader Ghaffari,Ling, Ong Chiu,Mihankhah, Taraneh,Johan, Mohd Rafie,Ching, Juan Joon
, p. 194 - 199 (2018/12/04)
1,1′-(1,4-Butanediyl)bis(imidazole) was prepared by a modified method and its application as an efficient promoter was demonstrated for the mechanosynthesis of N-methyl imines using ball milling as a non-conventional process under solvent-free conditions. In this new protocol design, the bis-imidazole acted as a recyclable acid-scavenging agent. This efficient approach to the N-methyl imines displays a combination of the synthetic virtues of a non-conventional condensation reaction with ecological benefits and convenience of a facile mechanosynthetic process. The current method has advantages such as reduced waste by avoiding solvent, exclusion of hazardous materials during the reaction, elimination of handling an anhydrous gas in an evacuated container or a solution of methylamine in ethanol, good yields for relatively unreactive benzaldehydes containing electron-donating substituents, short reaction times, and metal- and acid-free conditions. Furthermore, the promoter was easily regenerated and reused several times with no significant loss of activity.
Anion-driven conformation control and enhanced sulfate binding utilising aryl linked salicylaldoxime dicopper helicates
Stevens, James R.,Plieger, Paul G.
experimental part, p. 12235 - 12241 (2012/01/31)
The synthesis and spectroscopic analysis of both "metal-only" and anion encapsulated dicopper(ii) double helicates utilising a new 1,4-aryl spacer is described. X-Ray crystallographic analysis of the complexes reveal that the aromatic spacer increases rig
Bis-imine-cyclometalated macrocycles: Synthesis, characterization and observation of solution behaviour
Li, Hao,Han, Ying-Feng,Jin, Guo-Xin
experimental part, p. 4982 - 4993 (2011/08/02)
A novel class of cyclometalated macrocycles [(Cp*Ir) 2(R-NC-C6H2-CN-R)2] 2(pyrazine)2·(OTf)4 [R = Ph (4a), p-MeOC6H4 (4b), p-MeC6H4 (4c), p-ClC6H4 (4d), Me (4e)]; [(Cp*Rh) 2(R-NC-C6H2-CN-R)2] 2(pyrazine)2·(OTf)4 [R = Ph (4a′), p-MeOC6H4 (4b′), p-MeC6H4 (4c′)] and [(Cp*Ir)2(R-CN-C6H 4-NC-R)2]2(pyrazine)2·(OTf) 4 [R = Ph (5a), p-MeOC6H4 (5b)] was stepwise constructed through the double-site C-H activation of aromatic bis-imine substrates. The structures of binuclear complexes and tetranuclear macrocycles were confirmed by single-crystal X-ray diffraction. Isomers were found both in binuclear species and macrocyclic complexes. Flexible substrates led to the existence of isomers for binuclear species, yet gave no isomers after macrocyclic constructions; rigid ones, in contrast, led to isomers only for macrocyclic species. The isomers of tetranuclear macrocycles were thermodynamically stable to reversible transformation on a scale of days. Robust bonding and a certain degree of rigidity were invoked to explain the existence of isomers. This is the first example, to our knowledge, in which coordinated macrocycles containing half-sandwich Cp*M (M = Ir, Rh) fragments have been constructed, without a dynamic reversible process.
Preparation of Benzenetetracarboxylic Acids by the Cobalt-Catalyzed Carbonylation of Schiff Bases from Benzenedicarbaldehydes and Subsequent Oxidation
Kajimoto, Tsunesuke,Tsuji, Jiro
, p. 1685 - 1690 (2007/10/02)
Schiff bases (3a-d and 4a-c), synthesized from benzenedicarbaldehydes (terephthalaldehyde and isophthalaldehyde) and primary amines (methylamine, ethylamine, butylamine, and aniline), were carbonylated in the presence of Co2(CO)8 under an elevated pressure at 200-290 deg C to give dicarbonylated products, benzodipyrrolediones (5a-d, 10a-c, and 11a-c), in high yields. 1,2,3,4-Benzenetetracarboxylic acid (prehnitic acid) and 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid) were prepared selectively by the oxidation of the benzodipyrrolediones with nitric acid.Structu ral analysis of the benzodipyrrolediones by NMR spectra and the mechanism of the carbonylation reaction are discussed.
