112-14-1Relevant articles and documents
Diversification of shotgun process
Nagano, Yoshifumi,Orita, Akihiro,Otera, Junzo
, p. 5569 - 5578 (2003)
Three protocols for shotgun process are put forth in which simultaneous multi-fold reactions occur exclusively to each other. The first one involves simple combination of selective and non-selective reactions. Even if the simple protocol fails to give rise to the high selectivity, satisfactory outcome can be achieved by kinetic control or adjustment of functional groups.
ALKYLATIONS EN ABSENCE DE SOLVANT ORGANIQUE. EFFETS D'ADDITION D'OXYDES MINERAUX ET DE SELS D'AMMONIUM - II. PREPARATION AISEE D'ESTERS PAR ALKYLATION DE L'ANION ACETATE DANS DES CONDITIONS DOUCES ET ECONOMIQUES
Barry, J.,Bram, G.,Decodts, G.,Loupy, A.,Pigeon, P.,Sansoulet, J.
, p. 2673 - 2677 (1983)
Allyl, benzyl, n-butyl, n-octyl and cetyl acetates are obtained in very good yields (>=92percent) at room temperature by reacting finely-ground CH3COOK and the corresponding alkyl bromide without any solvent and in the presence of catalytic amounts of tetra-alkyl ammonium salts (NBu4Br or Aliquat 336).Effects of addition of mineral oxides have been studied: catalytic effects due to small quantities of TiO2, ZrO2, talc, glass dust and Celite, inhibition effects by large amounts of these solids or their highly hydroxylated analogues (alumina and silica gel).
Organotin catalysts rafted onto cross-linked polystyrene supports through polar spacers
Pinoie, Vanja,Biesemans, Monique,Willem, Rudolph
, p. 135 - 141 (2010)
The present study investigates the suitability of a HypoGel support bearing oligomeric poly(ethylene glycol) (PEG) chains to act as an insoluble carrier for grafted organotin catalysts. Through the introduction of polar spacers, an improved swelling and site accessibility in the polar media typically involved in transesterification reactions are targeted. Advanced structural investigation shows that quantitative conversion into the targeted HypoGel-supported organotin trichloride is hampered by the existence of intra-and/or intermolecular donor-acceptor O → Sn interactions caused by the presence of donor moieties in the PEG-linker. Support is provided to the proposal that the latter interactions are at the origin of the moderate catalytic performance displayed by these HypoGel-supported catalysts, achieving only 41% conversion after 2 hours in the transesterification of ethyl acetate and n-octanol. In contrast with similar organotin catalysts supported by an alkyl spacer, the HypoGel-supported materials appear to be poorly recyclable and display poor leaching resistance. Copyright
An Efficient Acylation of Tertiary Alcohols with Isopropenyl Acetate Mediated by an Oxime Ester and Cp*2Sm(thf)2
Tashiro, Daisuke,Kawasaki, Yumi,Sakaguchi, Satoshi,Ishii, Yasutaka
, p. 8141 - 8144 (1997)
An efficient method for the acylation of tertiary alcohols with isopropenyl acetate (1) by the use of an oxime and Cp*2Sm(thf)2 as catalyst was developed. Thus, various types of tertiary alcohols could be acylated with 1 in the presence of a catalytic amount of cyclohexanone oxime acetate (2) and Cp*2Sm(thf)2 under mild conditions to form the corresponding acetates in excellent yields. Acid-sensitive terpene alcohols such as linalool were successfully acetylated by the present method to give acetyl linalool in quantitative yield. This method enables an alternative acylation of tertiary alcohols under acid-free conditions.
Alkylation of potassium acetate in "dry media" thermal activation in commercial microwave ovens
Bram, Georges,Loupy, Andre,Majdoub, Mustapha,Gutierrez, Elvira,Ruiz-Hitzsky, Eduardo
, p. 5167 - 5176 (1990)
Microwave irradiation using commercial domestic ovens is very efficient to activate potassium acetate on alumina in the absence of solvent ("dry media") giving rise to remarkable rate enhancements in alkylation reactions with long chain halides. These reactions can be performed quantitatively on appreciable amounts of materials in open standard pyrex vessels.
Discriminating between dispersion and lyoprotection effects in biocatalysis in organic media
Secundo, Francesco,Carrea, Giacomo,Veronese, Francesco Maria
, p. 551 - 554 (2002)
The increment of activity and solubility in 1,4-dioxane of lipase B from Candida antarctica, lipase from Pseudomonas cepacia, and subtilisin, were investigated as a function of the methoxypoly(ethylene glycol)-protein (PEG-protein) ratio employed during lyophilization. Both activity and solubility markedly increased as the PEG-protein ratio was increased. The increment of activity at low PEG-protein ratios, however, was much higher than that of solubility. These data suggest that the PEG-induced activation effect is due mainly to a lyoprotection effect rather than to relaxation of diffusional limitations.
A powerful tool for acid catalyzed organic addition and substitution reactions
Turhanen, Petri A.,Veps?l?inen, Jouko J.
, p. 26218 - 26222 (2015)
A novel green chemistry tool for acid catalyzed reactions has been developed. The multipurpose tool is based on the ability of dry solid materials to donate protons (H+) to starting materials combined with the simultaneous use of a nucleophile (e.g. NaI). The methods enable the following reactions to be conducted at 20-50 °C: selective addition of iodine or alcohols to more substituted carbon in R2CCH2 systems (R ≠ H), esterification reactions, e.g. free fatty acids with methanol, and at higher temperatures, (60-100 °C): esterification of free fatty acids with hindered alcohols (isopropanol), addition of iodine to CC bonds, opening of oxygen(s) containing heterocyclic rings, selective substitution of primary OH groups to iodine in the presence of other functional groups or secondary alcohol groups, esterification of alcohols with nitriles (R-CN), transesterification of fatty acid triglycerides to biodiesel and selective derivatization of primary hydroxyl groups (-CH2OH) over secondary moieties of sugars without any protection. Most of the reactions were also performed by a re-used Dowex cation exchange resin.
Erbium(III) triflate as an extremely active acylation catalyst
Procopio, Antonio,Dalpozzo, Renato,De Nino, Antonio,Maiuolo, Loredana,Russo, Beatrice,Sindona, Giovanni
, p. 1465 - 1470 (2004)
Erbium(III) triflate is a powerful catalyst for the acylation of alcohols and phenols. The reaction works well for a large variety of simple and functionalized substrates by using different kinds of acidic anhydrides {Ac 2O, (EtCO)2O, [(CH3)3CO] 2O, Bz2O, and (CF3CO)2O} without isomerisation of chiral centres. Moreover, the catalyst can be easily recycled and reused without significant loss of activity.
ALKYLATION OF ANIONS ON SOLID INORGANIC SUPPORTS : AN INTERPRETATION OF THE FUNCTIONS OF THE SUPPORTS
Bram, G.,Decodts, G.
, p. 5011 - 5014 (1980)
In the anionic alkylation (CH3CO2K + n C8H17Br) on solid inorganic supports, silica impregnated with cationic surfactant appear to be as effective as alumina, while silica bearing ammonium groups covalently bonded to the support (SPHEROSIL QMA) exhibits increased effectiveness.An interpretation based upon the superficial charge of the solid surfaces is proposed.
INORGANIC SOLIDS IN "DRY MEDIA" AN EFFICIENT WAY FOR DEVELOPING MICROWAVE IRRADIATION ACTIVATED ORGANIC REACTIONS
Gutierrez, E.,Loupy, A.,Bram, G.,Ruiz-Hitzky, E.
, p. 945 - 948 (1989)
"Dry media" microwave irradiation accelerates pinacol rearrangement (on montmorillonite) or acetate alkylation (on alumina or silicagel) without the hazards due to high pressures in vessels when using solvents.
