51952-99-9Relevant academic research and scientific papers
Synthesis, structural characterization, aromatic characteristics, and metalation of neo-confused porphyrins, a newly discovered class of porphyrin isomers
Li, Ruoshi,Lammer, Aaron D.,Ferrence, Gregory M.,Lash, Timothy D.
, p. 4078 - 4093 (2014/05/20)
Neo-confused porphyrins represent a unique family of porphyrin isomers that retain overall aromatic characteristics by virtue of a 17-atom 18π electron delocalization pathway. These porphyrin analogues have a pyrrolic subunit linked in a 1,3-fashion so that a nitrogen atom is directly connected to a meso-bridging carbon. Pyrrole-3-carbaldehydes were shown to react with sodium hydride and 5-acetoxymethylpyrrole-2-carbaldehydes in DMF to give the crucial neo-confused dipyrrolic dialdehyde intermediates. MacDonald "2 + 2" condensation of the dialdehydes with a dipyrrylmethane afforded a dihydroporphyrinoid, and subsequent oxidation with 0.2% aqueous ferric chloride generated a series of fully conjugated neo-confused porphyrins. Unusual dihydroporphyrin byproducts were also identified. Reaction of neo-confused porphyrins with nickel(II) or palladium(II) acetate in refluxing acetonitrile gave excellent yields of the corresponding organometallic derivatives. Proton NMR spectroscopy demonstrates that the diatropic character of this system is diminished compared to regular porphyrins, although neo-confused porphyrins retain porphyrin-like UV-vis spectra. Protonation led to the sequential formation of mono- and dicationic species. Proton NMR spectra for the dications showed the presence of enhanced diamagnetic ring currents.
Facile synthesis of 2,3,7,8-tetramethyl-2,2′-dipyrrin trifluoroacetate and its X-ray crystal structure
Datta, Suchitra,Lightner, David A.
body text, p. 1113 - 1117 (2009/12/01)
3,4-Dimethyl-1H-pyrrole-2-carboxylic acid was converted to 2,3,7,8-tetramethyl-2,2′-dipyrrin by the action of trifluoroacetic acid and ethyl orthoformate. A crystal of the dipyrrin was grown from dichloromethane-n-hexane and an X-ray crystallographic structure of its trifluoroacetate salt was determined.
New one-step synthesis of 3,4-disubstituted pyrrole-2,5-dicarbaldehydes
Tardieux, Catherine,Bolze, Frederic,Gros, Claude P.,Guilard, Roger
, p. 267 - 268 (2007/10/03)
A smooth and convenient one-step synthesis of 3,4-disubstituted pyrrole- 2,5-dicarbaldehydes 2 is reported. This reaction involves the condensation of β-substituted pyrrole-2-carboxylic acids with triethyl orthoformate in trifluoroacetic acid to give the title compounds in good yield.
Synthesis and unusual properties of expanded bilirubin analogs
Nogales, Daniel F.,Timothy Anstine,Lightner, David A.
, p. 8579 - 8596 (2007/10/02)
Pentapyrrole analogs of bilirubin and biliverdin have been prepared along with corresponding analogs where two dipyrrinones are attached to p-xylyl and m-xylyl groups. As determined by spectroscopic analysis and molecular modelling, the 'expanded' yellow
A Convenient General Method for the Synthesis of Pyrrole-2,5-dicarbaldehydes
Cadamuro, Silvano,Degani, Iacopo,Fochi, Rita,Gatti, Antonella,Piscopo, Laura
, p. 2939 - 2944 (2007/10/02)
A new general method for the synthesis of pyrrole-2,5-dicarbaldehyde and its 3-mono- and 3,4-disubstituted derivatives is reported.It involves the intermediate formation of the corresponding 2,5-bis(1,3-benzodithiol-2-yl)pyrroles followed by hydrolysis with HgO-35percent aq.HBF4-DMSO.Pyrrole-2,5-dicarbaldehyde was obtained in overall yields of 43-65percent, whilst that of the derivatives was 32-90percent.Moreover the methylation of the corresponding dithiolic intermediate with further hydrolysis resulted in the formation of 1-methylpyrrole-2,5-dicarbaldehyde in 90percent overall yield.
Synthesis of 6H-Pyrrolotriazoles and 5H-Pyrrolotetrazoles: Alkylation and Acylation of the Monoanions
Dulcere, Jean-Pierre,Tawil, Mohamed,Santelli, Maurice
, p. 571 - 575 (2007/10/02)
Thermal cyclization of 1-azido-2-penten-4-ynes and 4-azido-2-butenenitriles led to 6H-pyrrolotriazoles and 5H-pyrrolotetrazoles, respectively, in good yields.Upon treatment with methyllithium these heterocyclic compounds gave the corr
Synthetic Studies Relevant to Biosynthetic Research on Vitamin B12. Part 2. Syntheses of C-Methylated Chlorins Via Lactams
Battersby, Alan R.,Fookes, Christopher J. R.,Snow, Roger J.
, p. 2733 - 2741 (2007/10/02)
C-Metylyted chlorins have been synthesised by two approaches.For one, ring-B and ring-C of the final chlorin were built sequentially onto a thiolactam system which acted as the A-D component.The preferred alternative method involved joining together a lac
Sapphyrins: Novel Aromatic Pentapyrrolic Macrocycles
Bauer, Victor J.,Clive, Derrick L.J.,Dolphin, David,Paine, John B.,Harris, Francis L.,et al.
, p. 6429 - 6436 (2007/10/02)
Sapphyrins are pentapyrrolic macrocycles containing one direct link and four bridging methine groups between the five pyrrolic subunits.The syntheses of decamethylsapphyrin, other peripherally alkylated derivatives, and metal complexes are described.The p
