85067-99-8Relevant academic research and scientific papers
Preparation of Benzenetetracarboxylic Acids by the Cobalt-Catalyzed Carbonylation of Schiff Bases from Benzenedicarbaldehydes and Subsequent Oxidation
Kajimoto, Tsunesuke,Tsuji, Jiro
, p. 1685 - 1690 (1983)
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.
Synthesis and Reactions of Cyclopalladated Compounds derived from N,N'-Dialkylbenzene-1,3-dicarbaldimines 1), Butyl or Octyl> and N,N'-Dibenzylbenzene-1,3-dicarbaldimine. Crystal Structure of 1(py)4>2 (py = pyridine)
Chakladar, Sukla,Paul, Parimal,Venkatsubramanian, K.,Nag, Kamalaksha
, p. 2669 - 2676 (1991)
The reactions of N,N'-dialkylbenzene-1,3-dicarbaldimines (alkyl = Et, H2L1; Bu, H2L2 or C8H17, H2L3) and N,N'-dibenzylbenzene-1,3-dicarbaldimine (H2L4) with Pd(O2CMe)2 have been studied.In all cases tetra-μ-acetato cyclopalladated compounds were obtained in which metallation had occurred at the 4,6-positions of the benzene ring.The μ-chloro analogues, , can be obtained either by reaction of the Schiff bases with Li2 or by metathesis of the acetato complexes.Bridge-splitting reactions of with pyridine (py), 4-methylpyridine, pyrazole, 3,5-dimethylpyrazole, amines, and a number of monoprotic bidendate chelating ligands, viz. acetylacetone, dibenzoylmethane and its monothio analogue, ethyl acetoacetate, salicylaldehyde, N-methylsalicylideneimine and sodium N,N-dipropyldithiocarbamate have also been investigateed.The products have been characterized by (1H) and (13)C NMR spectroscopy.The X-ray crystal structure of 1(py)4>2 has been determined which crystallizes in the triclinic space group P with a = 10.889(1), b = 16.981(2), c = 10.227(1) Angstroem, α = 92.99(1), β = 93.14(1), γ = 73.65(1) deg and Z = 2; refinement led to R = 0.059 and R' = 0.062 using 3620 unique reflections with I > 3?(I).
A palladium-catalyzed multicomponent coupling approach to π-conjugated oligomers: Assembling imidazole-based materials from imines and acyl chlorides
Siamaki, Ali R.,Sakalauskas, Marc,Arndtsen, Bruce A.
supporting information; experimental part, p. 6552 - 6556 (2011/09/13)
Just like tinkertoys: An alternative approach to access imidazole-containing π-conjugated materials is presented. The imidazole core was assembled at the same time as the oligomer by the palladium-catalyzed multicomponent coupling of imines, diimines, and di(acyl chloride)s, thus providing access to families of new conjugated materials, each formed in a one-step, catalytic reaction (see scheme; Ts=4-toluenesulfonyl). Copyright
