592-20-1Relevant academic research and scientific papers
Investigation of homopolymerization rate of perfluoro-4,5-substituted-2- methylene-1,3-dioxolane derivatives and properties of the polymers
Yang, Yu,Mike?, Franti?ek,Yang, Liang,Liu, Weihong,Koike, Yasuhiro,Okamoto, Yoshiyuki
, p. 277 - 281 (2006)
Five perfluoro-4,5-substituted-2-methylene-1,3-dioxolane monomers were synthesized. These monomers were found to readily polymerized by a free radical initiator in bulk and/or in solutions. Homopolymerization rates were determined using in situ 19F NMR measurements and found to be 0.25 to 1.66 × 10-4 mol L-1 s-1 in 1,1,2-trichlorotrifluoroethane at 41°C using the perfluorodibenzoyl peroxide as an initiator. The rates depend on the substituents on the 4 and 5 positions of the dioxolane. The purified polymers were thermally stable (up to 350°C). They show low refractive indexes (1.33-1.36 at 532 nm). They are transparent from UV to near IR region and have high glass transition temperatures (100-170°C).
AMBER ODORANT
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Page/Page column 29, (2020/12/11)
The present invention concerns compound of formula (I) in the form of any one of its stereoisomers or as a mixture thereof, and wherein R1 represents a hydrogen atom, a C1-3 alkyl group or C2-3 alkenyl group; X represents an oxygen atom when R2 represents a C1-4 alkyl group or C2-4 alkenyl group or X represents a CH2-O group when R2 represents a C2-4 alkenyl group or a MeC=O group. The use as a perfuming ingredient of the invention's compound and the invention's compound as part of a perfuming composition or of a perfuming consumer product are also part of the present invention.
Microwave-Enhanced Coupling of Carboxylic Acids with Liquid Ketones and Cyclic Ethers Using Tetrabutylammonium Iodide/ t-Butyl Hydroperoxide
Macías-Benítez, Pablo,Moreno-Dorado, F. Javier,Guerra, Francisco M.
, p. 6027 - 6043 (2020/05/22)
The oxidative coupling of carboxylic acids with liquid ketones and cyclic ethers has been accomplished in minutes using t-butyl hydroperoxide in the presence of tetrabutylammonium iodide under microwave irradiation in the absence of a solvent. In addition to drastically shortening the reaction times, the use of microwaves resulted, in general, in yields equal to or higher than those obtained by conventional heating.
Exploring the catalytic activity of Lewis-acidic uranyl complexes in the nucleophilic acyl substitution of acid anhydrides
Takao, Koichiro,Akashi, Shin
, p. 12201 - 12207 (2017/03/08)
The catalytic activities of several uranyl complexes, such as N,N′-disalicylidene-o-phenelyenediaminato(ethanol)dioxouranium(vi) (UO2(salophen)EtOH), bis(dibenzoylmethanato)(ethanol)dioxouranium(vi) (UO2(dbm)2EtOH), pentakis(N,N-dimethylformamide)dioxouranium(vi) ([UO2(DMF)5]2+), and tetrakis(triphenylphosphine oxide)dioxouranium(vi) ([UO2(OPPh3)4]2+), were examined in the nucleophilic acyl substitution of acid anhydrides. Among them, [UO2(OPPh3)4]2+ was the most efficient to give ethyl acetate and acetic acid from acetic anhydride (Ac2O) and ethanol, and was resistant towards decomposition during the catalytic reaction. Several nucleophiles were also subjected to the catalytic acylation reaction using acetic and pivalic anhydride. Kinetic and spectroscopic studies suggested that [UO2(OPPh3)4]2+ interacts with Ac2O to form [UO2(Ac2O)(OPPh3)3]2+. Interaction of this actual catalyst with additional Ac2O determines the rate of the overall nucleophilic acyl substitution reaction.
N-Isocyanimino-Triphenylphosphorane (Ph 3Pnnc) as an Efficient Reagent for the Preparation of Fully Substituted 1,3,4-Oxadiazoles via Intramolecular Aza-Wittig Reaction in Water
Jafari, Ali,Ramazani, Ali,Asiabi, Pegah Azimzadeh,Sadri, Fariba,Joo, Sang Woo
, p. 2246 - 2254 (2015/12/20)
An efficient green protocol for the synthesis of 1,3,4-oxadiazoles derivatives via a one-pot three-component reaction of aromatic carboxylic acids, N-isocyanimino-Triphenylphosphorane and ester derivatives of 2-oxopropyl alcohol (2-oxopropyl benzoate, 2-oxopropyl-4-bromobenzoate and 2-oxopropyl acetate) in water at room temperature have been developed. The present methodology offers several advantages such as a simple procedure, high yields, environmental friendliness and the absence of any volatile and hazardous organic solvents.
Regioselective hydration of terminal alkynes catalyzed by a neutral gold(I) complex [(IPr)AuCl] and one-pot synthesis of optically active secondary alcohols from terminal alkynes by the combination of [(IPr)AuCl] and Cp?RhCl[(R, R)-TsDPEN]
Li, Feng,Wang, Nana,Lu, Lei,Zhu, Guangjun
, p. 3538 - 3546 (2015/04/14)
A neutral gold(I) complex [(IPr)AuCl] (IPr = 1,3-bis(diisopropylphenyl)imidazol-2-ylidene) was found to be a highly effective catalyst for the hydration of terminal alkynes, including aromatic alkynes and aliphatic alkynes. The desired methyl ketones were obtained in high yields with complete regioselectivities. Furthermore, a series of optically active secondary alcohols could be obtained in high yield with good to excellent enatioselectivities via one-pot sequential hydration/asymmetric transfer hydrogenation (ATH) from terminal alkynes by the combination of of [(IPr)AuCl] and Cp?RhCl[(R,R)-TsDPEN] (Cp? = pentamethylcyclopentadienyl, TsDPEN = N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine). Notably, this research exhibited the potential of the direct use of neutral gold(I) complexes instead of cationic ones as catalysts for the activation of multiple bonds for organic synthesis.
The reaction of N-isocyaniminotriphenylphosphorane with ester derivatives of 2-oxopropyl alcohol (2-Oxopropyl 4-Bromobenzoate, 2-Oxopropyl Benzoate, and 2-Oxopropyl Acetate) in the presence of aromatic carboxylic acids: A one-pot efficient three-component reaction for the synthesis of fully substituted 1,3,4-oxadiazole derivatives
Ramazani, Ali,Ahmadi, Yavar,Karimi, Zahra,Rezaei, Aram
, p. 1447 - 1451 (2013/02/23)
Reactions of N-isocyaniminotriphenylphosphorane with ester derivatives of 2-oxopropyl alcohol (2-oxopropyl 4-bromobenzoate, 2-oxopropyl benzoate, and 2-oxopropyl acetate) in the presence of aromatic carboxylic acids proceed smoothly at room temperature and in neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in high yields. The reaction proceeds smoothly and cleanly under mild conditions and no side reactions were observed.
A one-pot efficient four-component reaction for the synthesis of 2-(arylamino)-2-(5-aryl-1,3,4-oxadiazol-2-yl)propyl benzoate (or acetate) derivatives
Ramazani, Ali,Ahmadi, Yavar,Malekzadeh, Asemeh Mashhadi,Rezaei, Aram
scheme or table, p. 692 - 698 (2012/01/03)
Reactions of (N-isocyanimino) triphenylphosphorane with 2-oxopropylbenzoate (or acetate) in the presence of aromatic carboxylic acids and primary amines proceed smoothly at room temperature and in neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in high yields. The reaction proceeds smoothly and cleanly under mild conditions, and no side reactions were observed.
Lead(IV) acetate mediated cleavage of β-hydroxy ethers: Enantioselective synthesis of α-acetoxy carbonyl compounds
Alvarez-Manzaneda, Enrique,Chahboun, Rachid,Alvarez, Esteban,Alvarez-Manzaneda, Ramón,Mu?oz, Pedro E.,Jimenez, Fermín,Bouanou, Hanane
experimental part, p. 8910 - 8917 (2011/12/01)
α-Acetoxy aldehydes or α-acetoxy ketones can be efficiently synthesized by treating 2,3-epoxy primary alcohols with lead tetraacetate. The reaction, which proceeds with complete regio- and stereoselectivity facilitates the enantioselective synthesis of α-acetoxy carbonyl compounds from allyl alcohols, via Sharpless epoxidation. Cyclic β-hydroxy ethers, with an oxygenated five-, six- or seven-membered ring, are transformed into α-acetoxy ethers.
Synthesis of a dimethylfuran-containing macrolide insect pheromone
Petroski, Richard J.,Bartelt, Robert J.,Vermillion, Karl
experimental part, p. 1389 - 1405 (2009/09/26)
The synthetic pathway to the furan-containing macrolide pheromone (1) of Galerucella beetles was shortened from 13 steps in the original synthesis to 10 steps, and the overall yield was increased greater than six-fold. A concise Reformatsky-based sequence of reactions was utilized to construct the key precursor, 2,3-dimethyl-2-butenolide. Reduction of the butenolide with diisobutylaluminum hydride afforded 3,4-dimethylfuran. A one-pot sequence of lithiation, alkylation by a tetrahydropyranyl (THP)-containing iodide, a second lithiation, and, finally, formylation gave the required tetrasubstituted furan intermediate, 3,4-dimethyl-5-[5-(tetrahydrofuran-2-yloxy)pentyl]-2-furaldehyde. To continue construction of the three-carbon acyl side chain, the aldehyde was converted to an unsaturated ester by a Horner-Wadsworth-Emmons (HWE) condensation with triethyl phosphonoacetate. After reduction of the double bond in the ester side chain and removal of protective groups, the lactone ring was closed using the Mitsunobu method, which is milder, is simpler, and could be accomplished with less solvent than the previous (Yamaguchi) method.
