Search results for "Phosphonium"
showing 10 items of 168 documents
Synthesis and Biological Evaluation of Combretastatin A-4 and Three Combretastatin-Based Hybrids
2012
The syntheses of combretastatin A-4 from gallic acid and of three combretastatin-based hybrids are described. Starting from commercial gallic acid, the phosphonium salt (3,4,5-trimethoxybenzylphosphonium bromide) is synthesized and coupled, through a Wittig reaction, with several aldehydes, including methoxymethyl-protected isovanillin, the aldehyde γ-bicyclohomofarnesal having a labdane skeleton, 3-(3-pyridyl) propanal, and furfural. The biological properties of the cis-coupled compounds as cytotoxic, antiviral and antifungal agents are also reported. In addition, pyrogallol, gallic and 3,4,5-trimethoxybenzoic acids have been studied biologically.
Phosphororganische Verbindungen, 85. Kinetische Untersuchungen der Umsetzung organischer Phosphorverbindungen mit Nucleophilen und Supernucleophilen
1977
Bei der alkalischen Spaltung von quartaren Phosphoniumsalzen und tertiaren Phosphinoxiden zeigt HOO⊖ keinen α-Effekt. Die Spaltung der P–C-Bindung wird auch nicht durch Gruppen erleichtert, welche uber die Ausbildung von H-Brucken den Angriff von HOO⊖ am Phosphoniumzentrum fordern. — In Ubereinstimmung mit den Ergebnissen anderer Autoren wird bei der Hydrolyse der Phosphin-, Phosphon- und Phosphorsaureester 1, 2 und 3 in Gegenwart von H2O2 ein α-Effekt beobachtet, der sich in einer Hydrolysebeschleunigung um einen Faktor von ca. 100 ausdruckt. Die Hydrolysegeschwindigkeit nimmt sowohl mit HO⊖ als auch mit HOO⊖ entsprechend folgender Reihenfolge ab: Diphenylphosphinsaure-(p-nitrophenyl)ester…
Synthesis of ortho-fonctionnalized arylphosphines and their applications
2020
This thesis reports with the synthesis of ortho-functionnalized phosphines bearing phosphonium and 1,2,3-triazole moieties.The synthesis of phosphines-phosphoniums, using as key-step Phospha-Fries rearrangement and Appel reaction is described. Eight new phosphines- phosphoniums, bearing aryl, alkyl or ferrocenyl fragments on the phosphonium part, have been prepared with overall yields reaching 48%. These phosphines- phosphoniums have been used in the preparation of gold (I) complexes which have been characterized using spectroscopic methods and X ray diffraction. Both gold (I) complexes and phosphines-phosphoniums have been studied in biology and these compounds turned out to be cytotoxic i…
NMR enantiodifferentiation of triphenylphosphonium salts by chiral hexacoordinated phosphate anions
2003
BINPHAT anion—rather than TRISPHAT—is an efficient NMR chiral shift reagent for triphenylphosphonium salts containing stereogenic centers on the aliphatic side-chain. BINPHAT—rather than TRISPHAT—anion is an efficient NMR (1H and 31P) chiral shift reagent for chiral triphenylphosphonium salts.
Hydrophobic Encapsulated Phosphonium Salts-Synthesis of Weakly Coordinating Cations and their Application in Wittig Reactions
2015
Large and rigid tetraarylphosphonium tetrafluoroborate salts have been synthesized representing weakly coordinating cations with diameters of several nanometers. Divergent dendritic growth by means of thermal Diels-Alder cycloaddition was employed for the construction of the hydrophobic polyphenylene framework up to the third generation. X-ray crystal structure analysis of first-generation phosphonium tetrafluoroborate supported the rigidity of the non-collapsible shell around the phosphorus center and gave insight into solid-state packing and cation-anion distances. Copper(I)-catalyzed azide-alkyne ligation served as reliable method for the preparation of a first-generation triazolylphenyl…
CCDC 854063: Experimental Crystal Structure Determination
2012
Related Article: A.Molina-Ontoria, R.Garcia, A.Gouloumis, F.Giacalone, M.R.Torres, N.Martin|2012|Eur.J.Org.Chem.|2012|3581|doi:10.1002/ejoc.201200115
CCDC 1014823: Experimental Crystal Structure Determination
2015
Related Article: Moussa Ali , Lucile Dondaine , Anais Adolle , Carla Sampaio , Florian Chotard , Philippe Richard , Franck Denat , Ali Bettaieb , Pierre Le Gendre , Véronique Laurens , Christine Goze , Catherine Paul , and Ewen Bodio|2015|J.Med.Chem.|58|4521|doi:10.1021/acs.jmedchem.5b00480
CCDC 915599: Experimental Crystal Structure Determination
2013
Related Article: Michael Giese, Markus Albrecht, Arto Valkonen, Kari Rissanen|2013|Eur.J.Org.Chem.|2013|3247|doi:10.1002/ejoc.201201704
CCDC 915602: Experimental Crystal Structure Determination
2013
Related Article: Michael Giese, Markus Albrecht, Arto Valkonen, Kari Rissanen|2013|Eur.J.Org.Chem.|2013|3247|doi:10.1002/ejoc.201201704
CCDC 981912: Experimental Crystal Structure Determination
2014
Related Article: Abdou K. D. Dimé, Charles H. Devillers, Hélène Cattey, Dominique Lucas|2014|Dalton Trans.|43|14554|doi:10.1039/C4DT00221K