两种长久以来被用作其光化学和代谢研究模型化合物的胆红素类似物取代了黄胆红素酸和and基吡咯烷酮的典型内酰胺β-烷基取代基,导致两亲性增加。由3,4-二甲氧基吡咯啉-2-酮与适当的吡咯α-醛进行碱催化缩合反应合成的黄原胆红酸和k基吡咯烷酮的2,3-二甲氧基类似物是黄色的二吡啶酮类,它们在分子内形成分子间氢键合的二聚体。通过1 H NMR和蒸气压渗压法测定,通过X射线晶体学测定和在CHCl 3中测定固体。这两种新的双吡啶酮在水中的溶解度比其母体双吡啶酮高约十倍。
3,4-Dialkoxypyrroles and 2,3,7,8,12,13,17,18-Octaalkoxyporphyrins
作者:Andreas Merz、Roland Schropp、Eleonore Dötterl
DOI:10.1055/s-1995-3993
日期:1995.7
A five-step general synthesis of 3,4-dialkoxypyrroles 7c-f is described starting with the condensation of dimethyl N-benzyliminodiacetate (1b) and diethyl oxalate to give dimethyl 1-benzyl-3,4-dihydroxypyrrole-2,5-dicarboxylate (2b), which is bis-O-alkylated to the corresponding 3,4-diethers 3c-g. Pyrrole N-benzyl cleavage followed by ester hydrolysis and decarboxylation leads to 7c-f in 10-50% overall yield. Pyrroles 7c-f react with formaldehyde or benzaldehydes to give meso-H- (8a-d) or meso-tetraaryloctaalkoxyporphyrins 9a-g in moderate yields.
Chiral spiro phosphoric acid-catalysed enantioselective reaction of ketenes with N–H pyrroles
作者:Qian-Yi Wang、Teng-Fei Liu、Li-Feng Chu、Yun Yao、Chong-Dao Lu
DOI:10.1039/d1cc05307h
日期:——
In the presence of a chiral spiro phosphoric acid catalyst, the asymmetric reaction of disubstituted ketenes with N–H pyrroles occurred to afford enantioenriched C-acylated pyrroles bearing α-stereogenic carbon centres. The described reaction constitutes a rare example of a catalytic asymmetric reaction of ketenes with carbon-based nucleophiles.
Assemblies comprising anion complexes of Ï-extended oligopyrrole derivatives and counter cations, as well as those of anion-free receptor molecules, exhibited the formation of mesophases based on columnar structures using electrostatic and ÏâÏ interactions.
The first liquid-crystalline, expanded porphyrinsElectronic supplementary information (ESI) available: synthetic procedures, hydrazinophyrin characterisation, and crystal structure data. See http://www.rsc.org/suppdata/cc/b3/b307901p/
作者:Jonathan L. Sessler、Wyeth Callaway、Stephen P. Dudek、Richard W. Date、Vincent Lynch、Duncan W. Bruce
DOI:10.1039/b307901p
日期:——
Aliphatic derivatives of hydrazinophyrin, a new type of tetrapyrrolic macrocycle prepared by the condensation of 2,5-diformylpyrroles with hydrazine, exhibit liquid crystalline properties as judged from polarising optical microscopy; these hydrazinophyrins appear to be the first mesogens derived from an expandedporphyrin core.
developed by Merz et al. We show that the alkyl chain length has a huge influence on the polymer solubility and as a consequence on the surface morphology and hydrophobicity. Moreover, the alkyl chain length should be at least greater than eight carbons in order to obtain parahydrophobic properties. The properties are also controlled by the electrolyte nature. These materials can be used for many potential