54050-02-1Relevant academic research and scientific papers
Synthesis of deuterium labeled compounds by KCN-assisted hydrolysis of phosphonium salts
Lee, Ka Young,Na, Jeong Eun,Lee, Mi Jung,Kim, Jae Nyoung
, p. 5977 - 5981 (2004)
We developed a facile deuterium labeling method for benzylic or allylic halides or acetates systems. Conversion of the halides or acetates to the corresponding phosphonium salts and the following mild hydrolysis with KCN afforded the deuterium labeled compounds in good yields.
Wittig reactions on photoprotoporphyrin IX: New synthetic models for the special pair of the photosynthetic reaction center
Zheng, Gang,Shibata, Masayuki,Dougherty, Thomas J.,Pandey, Ravindra K.
, p. 543 - 557 (2007/10/03)
A first example of spirochlorin-chlorin dimer with fixed distances and orientations as potential model for the 'special pair' of the photosynthetic reaction center is discussed. For the preparation of such a novel structure, the Wittig reagent of the desired 'spacer' 5 was reacted with photoprotoporphyrin IX dimethyl ester 3 to produce the intermediate dimer 6, which on intramolecular [4 + 2] Diels-Alder cycloaddition gave an unexpected spirochlorin-chlorin dimer 9. Dehydration of dimer 6 under acid-catalyzed conditions generated the corresponding spirochlorinporphyrin dimer 16 in quantitative yield. The asymmetry in dimer 6 caused by the biphenyl-type anisotropic effect was confirmed by NMR and model studies. The formation of dihydrobenzoporphyrin 14 by reacting chlorin 3 with the phosphonium salt of p-methylbenzylbromide 10 and isolation of 8-phenanthrenevinylporphyrin 19 from chlorin 7 further confirmed our proposed mechanism for the formation of a spirochlorin-chlorin dimer 9. Following a similar approach, chlorin 3 on reacting with bis-phosphonium salt of 4,4'-bischloromethylbiphenyl produced conjugated chlorin dimer 25. The spectroscopic data obtained from these dimers suggest that, in these compounds, the individual chromophores are not behaving as an individual molecule, but as a single macrocycle. To examine whether the π-π interaction exhibited by dimer 9 resembles the structural arrangement of bacteriochlorophylls in reaction center (RC), we investigated the geometrical parameters used to characterize the π-π interactions in tetrapyrrolic macrocycles. Starting from the crystallographic coordinates of 9, the molecular mechanics energy minimization was performed to obtain the model dimer structure. The geometrical parameters that measure the single pyrrole ring overlap were used to compare the model structure with the crystallographic coordinates of the special pair in photosynthetic reaction center. The results indicated that the ring A of spirochlorin and the ring C of chlorin in our model dimer 9 mimic the ring A-ring A interaction found in the crystallographic special pairs, which are strategically placed by the surrounding photosynthetic reaction center protein matrix.
Wittig Reactions of Phosphoniomethylaryl Compounds with Sulfonated Aromatic and Heteroaromatic Aldehydes
Maerky, Michael
, p. 957 - 975 (2007/10/02)
Bis(triphenylphosphoniomethyl)aryl dichloride derivatives react with aromatic or heteroaromatic aldehydes which have a sulfonic or carboxylic group attached to the ring system, to yield stilbene compounds of a betaine-type structure.These betaines are reacted further with various aromatic or heteroaromatic aldehydes yielding asymmetrically substituted derivatives in excellent yields.This new method is widely applicable to the preparation of water-soluble, fluorescent whitening agents of the bis-stilbene type.
