641-74-7Relevant articles and documents
Direct Amination of Isohexides via Borrowing Hydrogen Methodology: Regio- and Stereoselective Issues
Bahé, Florian,Grand, Lucie,Cartier, Elise,Jacolot, Ma?wenn,Moebs-Sanchez, Sylvie,Portinha, Daniel,Fleury, Etienne,Popowycz, Florence
supporting information, p. 599 - 608 (2020/02/04)
The regio and diastereoselective direct mono or diamination of bio-based isohexides (isosorbide and isomannide) has been developed through borrowing hydrogen (BH) methodology using a cooperative catalysis between an iridium complex and a Br?nsted acid. The access to chiral amino-alcohol (NH2-OH) and diamine (NH2-NH2), interesting optically pure bio-based monomers, was also proposed using BH strategy as a sustainable route for their obtention.
Kinetic analyses of intramolecular dehydration of hexitols in high-temperature water
Yamaguchi, Aritomo,Mimura, Naoki,Shirai, Masayuki,Sato, Osamu
, (2019/11/29)
Intramolecular dehydration of the biomass-derived hexitols D-sorbitol, D-mannitol, and galactitol was investigated. These reactions were performed in high-temperature water at 523–573 K without added acid catalyst. The rate constants for the dehydration steps in the reaction networks were determined at various reaction temperatures, and the activation energies and pre-exponential factors were calculated from Arrhenius plots. The yield of each product was estimated as a function of reaction time and temperature using the calculated rate constants and activation energies. The maximum yield of each product from the dehydration reactions was predicted over a range of reaction time and temperature, allowing the selective production of these important platform chemicals.
Unravelling the Mechanism of the Ru/C-Catalysed Isohexide and Ether Isomerization by Hydrogen Isotope Exchange
Engel, Rebecca V.,Niemeier, Johannes,Fink, Anja,Rose, Marcus
, p. 2358 - 2363 (2018/05/08)
In this article we show that the catalytic isomerization of isohexide sugar alcohols as well as their respective ethers can occur by a hydride-based mechanism rather than a dehydrogenation/re-hydrogenation. C?H bonds in α-position to hydroxy and ether groups are activated using Ru/C as solid catalyst at temperatures as high as 160 °C and above. Hydrogen isotope exchange experiments proved that a full hydride exchange and isomerization is possible for isohexides but unexpectedly also for their methyl ethers. This is of great importance as it proves the co-existence of the both mechanisms for reactions that were so far assumed to occur solely by a dehydrogenation/re-hydrogenation. Hence, this co-existence should be taken into account for kinetic investigations of such reaction systems especially in the conversion of biomass-based chemicals under hydrogenation conditions. (Figure presented.).