Search results for " bromide"
showing 10 items of 315 documents
ChemInform Abstract: A Simple Procedure for the Oxidation of Alcohols Using [Bis(acetoxy)iodo]benzene and a Catalytic Amount of Bromide Ions in Ethyl…
2015
Primary and secondary benzylic alcohols and secondary aliphatic alcohols were oxidized to the corresponding aldehydes and ketones by using [bis(acetoxy)iodo]benzene (BAIB) and a catalytic amount of bromide ions, from tetrabutylammonium bromide or KBr, in ethyl acetate. The catalytic role of the bromide ions was also highlighted in the oxidation of primary aliphatic alcohols and secondary allylic alcohols carried out in the presence of 1 mol% TEMPO.
Studien zum Vorgang der Wasserstoffübertragung 36 [1] Einfluß von Art und Struktur einiger Leitsalze auf die elektrochemische Spaltung von Diarylsulf…
1975
Tensammetrische Messungen bestatigen, das Tetraalkylammoniumsalze in Methanol mit steigender Kettenlange der Alkylreste und wachsender Konzentration zunehmend starker an der Quecksilberoberflache adsorbiert werden. Polarographie und Zyklovoltammetrie der Diarylsulfone 1–8 in Methanol lassen folgende Schlusse zu: 1 Unabhangig von der Alkylkettenlange der Tetraalkylammoniumsalze werden die Diarylsulfone 1–6 nach einem ECE-Mechanismus gespalten. Bei Verwendung von Alkalileitsalzen sind die genannten Sulfone polarographisch inaktiv. 2 Beim 4-Cyano-diphenylsulfon wird mit Tetramethylammoniumchlorid zyklovoltammetrisch keine Reversibilitat des ersten Elektronen ubergangs beobachtet, wohl aber mit…
ChemInform Abstract: Multi-Arm 1,2,3-Thiadiazole Systems.
2010
Benzene derivatives 2a–c with 6, 4, and 3 side chains bearing terminal 1,2,3-thiadiazole rings, respectively, have been prepared. Alkaline cleavage of 2a–c led to the corresponding alkynethiolates 6a–c, which were trapped by electrophiles such as benzyl bromide or iodomethane. The method provides an alternative to the thermal or photochemical cleavage of 1,2,3-thiadiazoles to thioketenes, which react further with nucleophiles.
Darstellung und charakterisierung von einigen neuen bis(1-phenylvinyl)-verbindungen
1974
Einige neue Bis(1-phenylvinyl)-Verbindungen (1b, c und 2a–d) wurden aus den entsprechenden Diacetylverbindungen und Phenylmagnesiumbromid dargestellt. Ihre IR-, NMR-und Massenspektren werden diskutiert. Some new bis(1-phenylvinyl) compounds (1b, c and 2a–d) were prepared from the corresponding diacetyl compounds and phenyl magnesium bromide. Their IR, NMR and mass spectra are discussed.
1963
Es wird gezeigt, das sich e-Caprolactam mit wasserfreiem Bromwasserstoff kationisch polymerisieren last und die dabei gebildeten Polymeren die Struktur von N-(Poly-e-aminocaproyl)-caprolactamen besitzen. Die charakteristische Diacylimidstruktur wird IR-spektroskopisch, durch die Hydroxamsaurereaktion und durch alkoholytische Abspaltung des C-terminalen Lactamringes nachgewiesen. Oligomerengemische, die durch kurzzeitige Umsetzung molarer Mengen an Caprolactam und Initiator bei 175–200°C erhalten werden, konnen durch Hochspannungspapierelektrophorese in einheitliche Individuen aufgetrennt werden. Die Umsetzung mit Hydroxylamin fuhrt zu Oligo-e-aminocapronhydroxamsauren, die sich mit Hilfe au…
Synthesis and Properties of Some Simple Organotitanium Compounds
1986
Before embarking on a detailed discussion of the titanation of carbanions, synthetic and physical organic aspects of several typical organotitanium (IV) compounds shall be surveyed, including thermal stability, aggregation state, X-ray structural data and bond energies. Some of this information is useful in understanding reactivity and selectivity in reactions with organic substrates. Low valent Ti (II) and Ti (III) shall be mentioned only on passing; the interested reader is referred to reviews [1].
Polymere ester von Säuren des phosphors, 5. Ringöffnende polymerisation des 2-phenoxy-1,3,2-dioxaphospholan durch Michaelis-Arbuzov-reaktion
1977
2-Phenoxy-1,3,2-dioxaphospholane (14) was polymerized by benzyl halogenides at temperatures between 120 and 200°C. It was found that the main chain consists predominantly of unexpected ethylene 1,2-ethanediphosphonate units 7; only about 10% of the monomer was incorporated as the expected 2-hydroxyethanephosphonate structure. An insertion mechanism, proposed by Harwood and Patel for the analogous polymerization of 2-phenyl-1,3,2-dioxaphospholane, does not agree with our experimental results. A hypothesis is developed involving a two step addition process, which exclusively occurs at the chain end. Alternating, one monomer molecule is added by a normal Michaelis-Arbuzov-reaction, and then a …
Multi-Arm 1,2,3-Thiadiazole Systems
1997
Benzene derivatives 2a–c with 6, 4, and 3 side chains bearing terminal 1,2,3-thiadiazole rings, respectively, have been prepared. Alkaline cleavage of 2a–c led to the corresponding alkynethiolates 6a–c, which were trapped by electrophiles such as benzyl bromide or iodomethane. The method provides an alternative to the thermal or photochemical cleavage of 1,2,3-thiadiazoles to thioketenes, which react further with nucleophiles.
Über Serotoninderivate mit cyclisierter Seitenkette, 1. Mitt. Darstellung der isomeren 3-(Piperidylmethyl)- und 3-(Piperidylmethyl)-5-hydroxyindole
1975
Es wird die Synthese der drei isomeren 3-(Pyridylmethyl)- und 3-(Piperidylmethyl)-5-hydroxyindole beschrieben. Die 3-(Pyridilmethyl)-5-benzyloxyindole wurden durch Kondensation von 5-Benzyloxyindolylmagnesiumbromid mit den drei isomeren Chlormethyl-pyridinbasen dargestellt. Katalytische Reduktion ihrer quartaren Salze fuhrte zu den entsprechenden Piperidinverbindungen. Die 5-Benzyloxyindole wurden durch hydrierende Debenzylierung in die 5-Hydroxyindolverbindungen ubergefuhrt. 3-(Pyridylmethyl)- and 3-(Piperidylmethyl)-5-hydroxyindoles The synthesis of the three isomeric 3-(pyridylmethyl)- and the 3-(piperidylmethyl)-5-hydroxyindoles is described. To obtain the 3-(pyridylmethyl)-3-benzyloxyi…
ChemInform Abstract: Synthesis and Self-Assembly of Novel Fluorous Cationic Amphiphiles with a 3,4-Dihydro-2(1H)-pyridone Spacer.
2011
Abstract The synthesis of fluorous (highly fluorinated) 3,4-dihydro-2(1 H )-pyridone-5-carboxylate cationic amphiphiles have been described, where the dihydropyridone serves as a spacer and either a pyridinium bromide or a triphenylphosphonium bromide form the polar cationic head group. The in water self-assembled aggregates have been observed by atomic force microscopy (AFM) and dynamic light scattering (DLS).