19686-73-8Relevant articles and documents
Cycloaddition of carbon dioxide to 1,2-epoxypropane catalyzed by tetra-t-butylphthalocyaninatoaluminium(III) hydroxide
Kasuga, Kuninobu,Kato, Takao,Kabata, Naohiko,Handa, Makoto
, p. 2885 - 2888 (1996)
Carbon dioxide was fixed as propane-1,2-diol carbonate (PDC) with 1,2-epoxypropane (EP) catalyzed by Al(OH) {pc(t-Bu)4} in the presence of such a quaternary ammonium halide (HAX) as [HO(CH2)2N(CH3)2(C4H 9)]X (X=Cl, Br, I). Although the yield was scarcely affected by the structure of HAX, it was dependent on the kind of halide ion. While PDC was formed in chloroform or dichloromethane, the yield decreased extremely in DMSO or pyridine, and PDC was not prepared in methanol. Although halohydrin was formed in a chloroform solution of EP, Al(OH){pc(t-Bu)4}, and HAX, it was not an intermediate. The formation of a hexa-coordinate complex of Al(OH){pc(t-Bu)4} with HAX and EP was spectroscopically confirmed, and the complex catalyzed the preparation of PDC from carbon dioxide and EP.
Reinvestigation of the conversion of epoxides into halohydrins with elemental halogen catalysed by thiourea
Soroka, Miros?aw,Goldeman, Waldemar
, p. 4233 - 4235 (2005)
In contrast to a previous literature report, thiourea is not a catalyst in the ring opening reaction of epoxides by means of bromine or iodine. Instead, thiourea reacts with the halogen to give a complex mixture of products, among them hydrogen halogenides, which are in fact the real epoxide ring opening reactants. The presence of water is crucial in this reaction.
O-phenylenediamine as a new catalyst in the highly regioselective conversion of epoxides to halohydrins with elemental halogens - A reinvestigation
Soroka, Miroslaw,Goldeman, Waldemar
, p. 169 - 174 (2006)
In contrast to a previous report, o-phenylenediamine is not a catalyst in the ring opening reaction of epoxides by means of bromine or iodine. The o-phenylenediamine is just a reactant which reacts with iodine to give phenazine-2,3-diamine and hydrogen iodide, or with bromine to give a mixture of brominated and polymerized products as well as hydrogen bromide. The hydrogen halogenides are in fact the real epoxide ring opening reactants. Springer-Verlag 2006.
Aliphatic carboxylic acid as a hydrogen-bond donor for converting CO2and epoxide into cyclic carbonate under mild conditions
Wang, Zheng,Wang, Yajun,Xie, Qianjie,Fan, Zhiying,Shen, Yehua
, p. 9403 - 9408 (2021)
The coupling of CO2 and epoxides is a promising way to reduce atmospheric carbon by converting it into value-added cyclic carbonate. Pursuing efficient catalysts is highly attractive for the title reaction. Herein, we developed simple and inexpensive catalyst systems of aliphatic carboxylic acids as the hydrogen-bond donor (HBD) and quaternary ammonium halides as the nucleophile to catalyze the CO2-epoxide coupling reaction with high efficiency and selectivity under mild conditions (80 °C and 4 bar CO2). The high activity of this catalyst system is retained even under ambient conditions. The effects of the acidity and steric hindrance of acids on the catalysis of CO2-epoxide coupling were systematically investigated. Lastly, the reaction mechanism was deduced and its rationality was further reinforced by exploring the interaction between a representative system AA/TBAB (acetic acid/tetrabutylammonium bromide) and propylene oxide (PO). The study of aliphatic carboxylic acids/quaternary ammonium halides provides a new way to design catalyst systems for the title reaction.
Primary Alcohols via Nickel Pentacarboxycyclopentadienyl Diamide Catalyzed Hydrosilylation of Terminal Epoxides
Lambert, Tristan H.,Steiniger, Keri A.
supporting information, p. 8013 - 8017 (2021/10/25)
The efficient and regioselective hydrosilylation of epoxides co-catalyzed by a pentacarboxycyclopentadienyl (PCCP) diamide nickel complex and Lewis acid is reported. This method allows for the reductive opening of terminal, monosubstituted epoxides to form unbranched, primary alcohols. A range of substrates including both terminal and nonterminal epoxides are shown to work, and a mechanistic rationale is provided. This work represents the first use of a PCCP derivative as a ligand for transition-metal catalysis.
Method for preparing halogen propanol and epoxypropane
-
Paragraph 0098; 0099; 0110; 0111; 0129; 0130, (2017/05/19)
The invention provides a method for preparing halogen propanol. The method comprises the following steps (1) halogen alcoholization: adding halogen hydride, H2O2, propylene and an HTS molecular sieve into a reaction device, and carrying out halogen alcoholization reaction to obtain the halogen propanol. The invention also provides a method for preparing epoxypropane with a halogenohydrin method. The method comprises the following steps: (1) halogen alcoholization: adding halogen hydride, H2O2, propylene and an HTS molecular sieve into the reaction device, and carrying out the halogen alcoholization reaction to obtain halogen propanol; (2) saponification: carrying out saponification reaction on halogen propanol and a hydroxide of alkali metal in step (1), and separating to obtain the epoxypropane and alkali halide metal salt; optionally (3) electroosmosis: carrying out bipolar membrane electroosmosis on the alkali halide metal salt obtained in step (2) to obtain the hydroxide of alkali metal and the halogen hydride. According to the methods, the halogen propanol or the epoxypropane can be prepared at extremely high selectivity and yield, and the discharging of waste water and waste residues can be drastically lowered.
H2TPP organocatalysis in mild and highly regioselective ring opening of epoxides to halo alcohols by means of halogen elements
Torabi, Parviz,Azizian, Javad,Zomorodbakhsh, Shahab
experimental part, p. 5508 - 5519 (2012/08/28)
We found that elemental iodine and bromine are converted to trihalide nucleophiles (triiodine and tribromide anion, respectively) in the presence of catalytic amounts of meso-tetraphenylporphyrins (H2TPP). Therefore a highly regioselective method for the synthesis of β-haloalcohols through direct ring opening of epoxides with elemental iodine and bromine in the presence of H2TPPs as new catalysts is described. At room temperature a series of epoxide derivatives were converted into the corresponding halohydrins resulting from an attack of trihalide species anion atoms at the less substituted carbon atom. This method occurs under neutral and mild conditions with high yields in various aprotic solvents, even when sensitive functional groups are present.
NOVEL CONJUGATES, PREPARATION THEREOF, AND THERAPEUTIC USE THEREOF
-
, (2012/09/11)
Provided herein are cryptophycin conjugates and compositions containing them. Methods of making and using such compounds also are provided
Highly regioselective ring opening of epoxides and aziridines using (bromodimethyl)sulfonium bromide
Das, Biswanath,Krishnaiah, Maddeboina,Venkateswarlu, Katta
, p. 4457 - 4460 (2007/10/03)
Epoxides and aziridines undergo ring opening efficiently with (bromodimethyl)sulfonium bromide at room temperature to form the corresponding β-bromohydrins and β-bromoamines, respectively. The conversions are highly regioselective and afford the products in excellent yields within a short period of time.
Comments on a Conversion of Epoxides to Halohydrins with Elemental Halogen Catalyzed by Phenylhydrazine: Tandem Electrophilic Halogenation of Aromatic Compounds and Epoxide Ring Opening to Halohydrins
Soroka, Miroslaw,Goldeman, Waldemar,Malysa, Piotr,Stochaj, Monika
, p. 2341 - 2344 (2007/10/03)
The halogenation of aromatic compounds by bromine or chlorine in the presence of an epoxide gives the corresponding halogenated aromatics and 2-halohydrins, both with good yields.
