70354-00-6Relevant articles and documents
H2-Free Re-Based Catalytic Dehydroxylation of Aldaric Acid to Muconic and Adipic Acid Esters
Ho?evar, Brigita,Pra?nikar, An?e,Hu?, Matej,Grilc, Miha,Likozar, Bla?
, p. 1244 - 1253 (2020/12/09)
As one of the most demanded dicarboxylic acids, adipic acid can be directly produced from renewable sources. Hexoses from (hemi)cellulose are oxidized to aldaric acids and subsequently catalytically dehydroxylated. Hitherto performed homogeneously, we present the first heterogeneous catalytic process for converting an aldaric acid into muconic and adipic acid. The contribution of leached Re from the solid pre-reduced catalyst was also investigated with hot-filtration test and found to be inactive for dehydroxylation. Corrosive or hazardous (HBr/H2) reagents are avoided and simple alcohols and solid Re/C catalysts in an inert atmosphere are used. At 120 °C, the carboxylic groups are protected by esterification, which prevents lactonization in the absence of water or acidic sites. Dehydroxylation and partial hydrogenation yield monohexenoates (93 %). For complete hydrogenation to adipate, a 16 % higher activation barrier necessitates higher temperatures.
Libraries for Receptor-Assisted Combinatorial Synthesis (RACS). The olefin metathesis reaction
Giger, Thomas,Wigger, Maria,Audétat, Stephan,Benner, Steven A.
, p. 688 - 691 (2007/10/03)
A library of alkenes is generated using the olefin metathesis reaction, and converted to a set of diols suitable for a receptor assisted combinatorial synthesis (RACS) experiment with borate as a linker.
Ozonolysis of Olefins, I. - Ozonolysis of 1,4-Cyclohexadiene and Acid-Catalysed Reaction of Primary Cleavage Products
Mittelbach, Martin,Poklukar, Norbert,Junek, Hans
, p. 185 - 188 (2007/10/02)
The reaction of 1,4-cyclohexadiene (1) with ozone under different reaction conditions was investigated.Complete ozonolysis of 1 in chloroform led to a highly explosive ozonide.Oxidative ozonolysis gave malonic acid in 30percent yield, ozonolysis in alcoholic solutions of HCl gave alkyl 3,3-dialkoxypropionates 3 in 60-70percent yield and small amounts of the 1,1,3,3-tetraalkoxypropane 4 as well as dialkyl malonate 5.Partial ozonolysis of1 in HCl/methanol led to a mixture of 3,5 and the corresponding (Z)-3-hexene derivatives 6a-c.Depending on the reaction time and concentration of HCl, also the two methanol addition products 7b and 7d could be obtained.To verify the structure of these two compounds, 4-methoxycyclohexene (8) was ozonized in HCl/methanol, which gave a mixture of 7a-d.
Ozonolyse von Olefinen, III: Saeurekatalysierte Ozonolyse von 3-Hexen-1,6- und 2-Penten-1,5-dicarbonylderivaten
Poklukar, Norbert,Mittelbach, Martin
, p. 203 - 207 (2007/10/02)
The ozonolysis of mono-unsaturated compounds containing the structural element =CH-CH2-R was investigated.Reductive ozonolysis of (E)-3-hexene-1,6-dioic acid gives methyl 3,3-dimethoxypropanoate (2), whereas ozonolysis of dimethyl (E)-3-hexene-1,6-dioate (1a) and (Z)-1,1,6,6-tetramethoxy-3-hexene (1b) in a methanolic solution of HCl leads to a mixture of 2, dimethyl malonate (3a) and 1,1,3,3-tetramethoxypropane (3b).The homologuos derivatives, dimethyl glutaconate (4a) and 1,1,5,5-tetramethoxy-2-pentene (4b), were ozonized to give mixtures of 2, 3, dimethyl oxalate (5), methyl 2,2-dimethoxyacetate (6a), and 1,1,2,2-tetramethoxyethane (6b).The ratios of the various reaction products were determined by gas chromatography.In each case the formation of the bifunctional derivatives 2 and 6a was favoured.
CC-KUPLUNGEN VON CO2 MIT 1,3-DIENEN AN EISEN(0)-KOMPLEXEN; CARBOXYLATBILDUNG UND FOLGEREAKTIONEN
Hoberg, Heinz,Jenni, Klaus
, p. 193 - 202 (2007/10/02)
1,3-Dienes react with CO2 at ligand-iron(0) systems to η3-allyl carboxylates.The dynamic allylic system is influenced by addition of further ligands such as phosphanes or maleic acid anhydride or acetic acid anhydride.The direction of this infl
