77116-74-6Relevant academic research and scientific papers
Production of Diethyl Terephthalate from Biomass-Derived Muconic Acid
Lu, Rui,Lu, Fang,Chen, Jiazhi,Yu, Weiqiang,Huang, Qianqian,Zhang, Junjie,Xu, Jie
supporting information, p. 249 - 253 (2016/01/25)
We report a cascade synthetic route to directly obtain diethyl terephthalate, a replacement for terephthalic acid, from biomass-derived muconic acid, ethanol, and ethylene. The process involves two steps: First, a substituted cyclohexene system is built through esterification and Diels-Alder reaction; then, a dehydrogenation reaction provides diethyl terephthalate. The key esterification reaction leads to improved solubility and modulates the electronic properties of muconic acid, thus promoting the Diels-Alder reaction with ethylene. With silicotungstic acid as the catalyst, nearly 100 % conversion of muconic acid was achieved, and the cycloadducts were formed with more than 99.0 % selectivity. The palladium-catalyzed dehydrogenation reaction preferentially occurs under neutral or mildly basic conditions. The total yield of diethyl terephthalate reached 80.6 % based on the amount of muconic acid used in the two-step synthetic process.
A study on the influence of a silicon group on the Curtius reaction
Verma, Rekha,Ghosh, Sunil K.
, p. 2377 - 2381 (2007/10/03)
The effect of a dimethyl(phenyl)silyl group at different positions with respect to an acyl azide moiety on the Curtius reaction has been investigated. A silyl group at the β-position enhanced the reaction rate by about three times compared to a non-silylated analog. However, a silyl group at the γ-position had only a minor influence on the reaction. A diacyl azide having a silyl group at the β-position with respect to one acyl azide group and at the γ-position with respect to the other acyl azide group has been prepared and subjected to the Curtius reaction in order to evaluate the possible synthetic potential which originates from the control exerted by the silicon group in such systems.
A DIASTEREO- AND ENANTIOSELECTIVE MICHAEL ADDITION OF CHIRAL AMIDE ENOLATES TO α,β-UNSATURATED ESTERS; A STEREOSELECTIVE SYNTHESIS OF (+)-DEHYDROIRIDODIOL AND (-)-ISODEHYDROIRIDODIOL
Yamaguchi, Masahiko,Hasebe, Koichi,Tanaka, Shinya,Minami, Toru
, p. 959 - 962 (2007/10/02)
(+)-Dehydroiridodiol and (-)-isodehydroiridodiol were synthesized stereoselecticely using the diastereo- and enantioselective Michael addition of chiral amide enolates to α,β-unsaturated esters.
Applications of Consecutive Radical Addition-Elimination Reactions in Synthesis
Baldwin, Jack E.,Kelly, David R.
, p. 682 - 684 (2007/10/02)
Alkyl radicals add to the tri-n-butylstannyl substituted terminus of several alkenes; elimination of the stannyl radical results in a preparatively useful, carbon-carbon bond forming reaction, under mild and neutral conditions.
On the Knowledge of the Catalytic Dimerization of Acrylic Acid Derivatives by Palladium Complexes. III. Reactions of β-Palladio Acrylates and Their Relation to the Catalytic Reaction
Oehme, G.,Pracejus, H.
, p. 798 - 808 (2007/10/02)
Complexes of the type L2PdCl(CH=CHCOOCH3) (L2 = 2PPh3 or Ph2PCH2CH2PPh2) were decomposed to dimethyl muconate by pyrolysis or by substraction of the phosphine ligands with (CH3CN)2PdCl2 in acetonitrile.The last mentioned reaction gave Δ3-dimethyl dihydromuconate in the presence of hydrochloric acid. Δ3-Dimethyl dihydromuconate was also formed by decomposition of (Ph2PCH2CH2PPh2)PdCl(CH=CHCOOCH3) with HBF4 in acetonitrile, but the analogous reaction in methyl acrylate as solvent gave Δ2-dimetyl dihydromuconate.Thus, we have simulated the formation of the two m ain products of the catalytic dimerization of methyl acrylate with palladium(II)chloride in a stoichiometric manner.Mechanisms with hydride and carbene intermediates are discussed.
