cis and trans Isomers distinguished by imidazole N-alkylation after Debus-Radziszewski reaction starting from 2,7-di-tert-butyl-pyrene-4,5,9,10-tetraone

Tetrahedron ◽  
2015 ◽  
Vol 71 (21) ◽  
pp. 3195-3202 ◽  
Author(s):  
Bin-Bin Ma ◽  
Yu-Xin Peng ◽  
Pei-Chen Zhao ◽  
Wei Huang
2008 ◽  
Vol 63 (10) ◽  
pp. 1149-1154 ◽  
Author(s):  
Werner Uhl ◽  
Andreas Vogelpohl

AbstractThe reaction of diethylaluminum hydride with the hydrazine derivatives 1-aminopyrrole and 1- aminopiperidine afforded the corresponding dialkylaluminum hydrazides (1 and 2) by the release of elemental hydrogen. Both products are dimeric in the solid state. While 1 adopts a cis arrangement of the pyrrole groups, a trans configuration was determined for the piperidine compound 2. Only 1 gives an equilibrium mixture of cis and trans isomers in solution. Similar compounds (3 and 4) were obtained by the treatment of the same hydrazines with di(tert-butyl)gallium hydride. Both products exhibit the trans configuration in the solid state, but interestingly only the piperidine derivative 4 shows a cis/trans equilibrium in solution.


1994 ◽  
Vol 49 (12) ◽  
pp. 1818-1826 ◽  
Author(s):  
Dietmar Seyferth ◽  
Holger Friedrich ◽  
Shane W. Krska

The di-tert-butyl peroxide-initiated reactions of triethyl- and tri-n-propylsilane with bis-(vinyldim ethylsilyl) compounds, CH2=CH(CH3)2SiXSi(CH3)2CH=CH2(X-O,CH2, NH,NCH3 and NSiMe3) resulted in hydrosilylation-cyclization to give mixtures of trialkylsilylm ethyl-substituted disilacyclohexanes and trialkylsilylm ethyl-substituted disilacyclopentanes. The ratio of six-membered to five-membered ring products obtained is dependent on the linking group X and decreased in the order X=O>CH2>NH>NCH3. For X = NSiMe3 only a mixture of the cis and trans isomers of the five-membered ring product was obtained.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4539
Author(s):  
Nguyen Minh Thuy ◽  
Vo Minh ◽  
Tran Ben ◽  
My Tuyen Thi Nguyen ◽  
Ho Ha ◽  
...  

Butterfly pea flower have great sensory attraction, but they have not yet been used widely in Vietnam. Extracts of butterfly pea flowers can be used conveniently as a natural blue colorant for food products. In this study, the identification of anthocyanin compounds in butterfly pea flowers was performed by UPLC coupled with a UV and Mass spectrometer instrument. Positive and negative ion electrospray MS/MS chromatograms and spectra of the anthocyanin compounds were determined. By analyzing the chromatograms and spectra for each ion, five anthocyanins were identified in the butterfly pea flower extract; these were delphinidin-3-(6”‐p-coumaroyl)-rutinoside, cyanidin 3-(6”-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl) glucose in both cis- and trans- isomers, cyanidin-3-(p-coumaroyl-glucoside) and delphinidin-3-pyranoside. Additionally, based on their intensity, it was determined that cyanidin-3-(p-coumaroyl-glucoside) was the most abundant anthocyanin, followed by cyanidin 3-(6”-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl-glucoside), delphinidin-3-(6”-p-coumaroyl)-rutinoside and delphinidin-3-pyranoside. In this study, cyanidin derivatives were discovered in butterfly pea flower extract, where these compounds had not been detected in previous studies.


2020 ◽  
Vol 153 (24) ◽  
pp. 244308
Author(s):  
Ali Abou Taka ◽  
Mark C. Babin ◽  
Xianghai Sheng ◽  
Jessalyn A. DeVine ◽  
Daniel M. Neumark ◽  
...  

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