- Vesicle formation from an amphiphilic porphyrin derivative at the air-water interface
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A tetraphenyl porphyrin derivative with two C16 alkyl chains covalently bound to each of the four peripheral phenyl rings through ether linkages formed multilayer clusters or vesicles at the air-water surface. More interestingly, spherical vesicles were also formed when deposited on appropriate solid surfaces, and these vesicles were stable even in dry conditions. Various microscopic images of the cast film deposited on a mica surface confirmed closed-ended nanotube/nanorod-type formation with necking and bulging. These narrow tubes are proposed to be intermediates for the formation of vesicles by fission at either side of the bulge. Such vesicular formation is not common when either cast or Langmuir-Blodgett films were deposited on a solid surface.
- Ghosh, Amrita,Choudhury, Sipra,Das, Amitava
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Read Online
- METHOD FOR PRODUCING REDUCED HALIDE COMPOUND HAVING UNDERGONE REDUCTION OF CARBON-CARBON UNSATURATED BOND
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A halide compound having one or more carbon-carbon unsaturated bonds is catalytically reduced with substantially no dehalogenation to produce a reduced halide compound in which at least one of the one or more unsaturated bonds is reduced. Specifically provided is a method for producing a reduced halide compound including steps of: reacting a nickel compound, a zinc compound, and a borohydride compound in a solvent to obtain a reduction catalyst; and subjecting a halide compound having one or more carbon-carbon unsaturated bonds to catalytic reduction in the presence of the reduction catalyst to reduce at least one of the one or more carbon-carbon unsaturated bonds to thereby obtain a reduced halide compound.
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Paragraph 0160; 0161; 0162; 0163; 0164; 0165
(2019/11/05)
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- Phosphine functionalized polyphosphazenes: soluble and re-usable polymeric reagents for highly efficient halogenations under Appel conditions
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In this paper we present the preparation and application of a novel soluble phosphine functionalized polyphosphazene (poly[3-(diphenylphosphino)propylamino]phosphazene) and investigate its application as a polymeric reagent. Upon chlorination of the pendant phosphine groups, the polymer was found to facilitate the rapid and efficient transformation of alcohols to the corresponding chlorides and bromides under Appel-type conditions. Reaction times followed by 31P NMR spectroscopy are shown to be rapid (several minutes) and the yields for the transformation of alcohols to the corresponding halides are in the range 80–99?%. The facile recovery of the oxidized polymeric agent by precipitation is also described, offering a significant advantage over notoriously difficult to remove small molecule phosphine oxide by-products. Furthermore the regeneration of the reactive phosphine chloride pendant groups is demonstrated, which could be efficiently re-used in a further chlorination reaction. Graphical abstract: [Figure not available: see fulltext.]
- K?nig, Michael,Linhardt, Anne,Brüggemann, Oliver,Teasdale, Ian
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p. 1575 - 1582
(2016/08/16)
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- Pivaloyl chloride/DMF: a new reagent for conversion of alcohols to chlorides
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An efficient procedure for conversion of alcohols into the corresponding chlorides is described. Pivaloyl chloride/DMF complex is employed as a mild and inexpensive reagent. A possible reaction mechanism is proposed.
- Dubey, Abhishek,Upadhyay, Arun K.,Kumar, Pradeep
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experimental part
p. 744 - 746
(2010/04/05)
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- A safe and efficient procedure to prepare alkyl and alkoxyalkyl chlorides and dichlorides by catalytic decomposition of the corresponding alkyl and alkoxyalkyl chloroformates and bischloroformates with hexabutylguanidinium chloride
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Small amounts of hexabutylguanidinium chloride (0.01 mol%) decomposes pure chloroformates or bischloroformates with different lengths of carbon chains by a semicontinuous process to diminish run-away risk, leading to chloride compounds with high yield and purity.
- Violleau,Thiebaud,Borredon,Le Gars
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p. 367 - 373
(2007/10/03)
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- A Convenient Conversion of Primary Amines into the Corresponding Halides Radical Promoted Halodeamination via N-Substituted-N-Tosylhydrazines
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Treatment of 1-substituted-1-tosylhydrazines with 2 equivalents of NCS or NBS in dry THF in presence of light affords the corresponding alkyl halides in good yields.This reaction presumably involves the initial formation of a stabilized hydrazyl radical which is halogenated in a radical chain process.Elimination of p-toluenesulfinic acid and extrusion of nitrogen leads to the corresponding alkyl halide.This route provides an improved method for halodeamination under neutral reaction conditions.
- Collazo, Luis R.,Guziec, Frank S.,Hu, Wei-Xiao Jr.,Pankayatselvan, Ratnadevi
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p. 7911 - 7914
(2007/10/02)
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- Organic Synthesis in Micellar Media. Oxidation of Alcohols and Their Conversion into Alkyl Chlorides
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The use of micelles was investigated for various organic reactions: oxidation of alcohols with sodium hypochlorite in micelles, oxidation of alcohols with hexadecyltrimethylammonium chromate as micelle, and conversion of primary alcohols to 1-chloroalkanes by aqueous hydrogen chloride in the presence of micelles.In all cases, product isolation was simple and satisfactory yields were obtained.
- Jursic, Branko
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p. 868 - 871
(2007/10/02)
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- CARBON-SULFUR BOND CLEAVAGE BY BENZYNE GENERATED FROM 2-CARBOXYBENZENEDIAZONIUM CHLORIDE
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The reaction of cyclic sulfides with benzyne generated from 2-carboxybenzenediazonium chloride affords ω-chloroalkyl phenyl sulfides in good yields.A similar type of reaction was also observed with acyclic sulfides.
- Nakayama, Juzo,Hoshino, Keiichi,Hoshino, Masamatsu
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p. 677 - 678
(2007/10/02)
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- Anodic Oxidation of Organoboranes
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Organoboranes are converted into more easily oxidizable borates by reaction with nucleophiles and the alkyl groups are dimerized by anodic oxidation.The oxidation potentials (Ep) of the borates depend strongly on the nature of the complexing nucleophile, for instance Ep = +0.37 V (vs.SCE) with OH- or +1.65 V with tetrahydrofuran.The dimer yields are optimized with trioctylborane (5) by variation of the electrode material and the elctrolyte.At the platinum anode in sodium hydroxide-methanol/tetrahydrofuran yields of 80percent are obtained for acyclic alkyl groups, and lo wer ones for cycloalkyl groups.They exceed those obtained by the Kolbe electrolysis or the oxidation with neutral hydrogen peroxide and they are comparable to those of the AgNO3 oxidation. - The selective preparation of unsymmetrical products from borates with different alkyl groups is not possible, the dimerization proceeds likely via free radicals that couple statistically.Good yields of unsymmetrical coupling products are achieved, when one olefin is used in excess.With choro-, ethoxy-, acetoxy-, and aryl-substituted alkyl groups the dimers are obtained in 21 - 66percent yield, with bromide the yield are lower and with nitriles the dimerization fails.
- Schlegel, Guenter,Schaefer, Hans J.
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p. 1400 - 1423
(2007/10/02)
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- Preparation of Alkyl Chlorides, Acid Chlorides, and Amides Using Polymer-Supported Phosphines and Carbon Tetrachloride: Mechanism of These Reactions
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Alcohols and thiols were converted into alkyl chlorides, carboxylic acids were converted into acid chlorides, and mixtures of carboxylic acids and amines were converted into amides by reaction with carbon tetrachloride and 1percent cross-linked polystyrenes containing phosphine residues.Some of these conversions were also effected by using a linear polymer containing phosphine residues.The reactions proceed in high yield, and isolation of the products is facilitated by the ready removal of all the polymer-supported species.The mechanism of the reactions between triphenylphosphine, carbon tetrachloride, and alcohols is complex, but the polymer-supported reactions appear to follow analogous pathways to the low molecular weight reactions as judged by the yields of chloroform and the number of equivalents of phosphine consumed per mole of alkyl chloride produced.The mechanism requires polymer-supported groups reacting together.The slow step in the reactions appears to be the generation of the chlorinating species.The polymer-supported reactions are faster than those using triphenylphosphine or 4-(diphenylphosphinyl)isopropylbenzene.It is suggested that this is due to a microenvironmental effect.
- Harrison, Charles R.,Hodge, Philip,Hunt, Barry J.,Khoshdel, Ezzatollah,Richardson, Graham
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p. 3721 - 3728
(2007/10/02)
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- PREPARATION OF ALKYL HALIDES VIA ORGANOTELLURIUMS
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The conversion of phenyltelluroalkanes to haloalkanes was studied in connection with the homologation of alkyl halides.Similar reactions of 1,1-bis(phenyltelluro)alkanes provided a new synthetic method of aldehydes.
- Chikamatsu, Kiyofumi,Otsubo, Tetsuo,Ogura, Fumio,Yamaguchi, Hachiro
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p. 1081 - 1084
(2007/10/02)
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