641-74-7Relevant articles and documents
Efficient and selective aqueous photocatalytic mono-dehydration of sugar alcohols using functionalized yttrium oxide nanocatalysts
Cheng, Yu,Fan, Chao,Guo, Lina,Huang, Benhua,Li, Xiaoyong,Luque, Rafael,Ma, Xiaomo,Meng, Xu,Pan, Cheng,Sun, Yang,Yang, Juncheng,Zhang, Junjie,Zhang, Weining,Zheng, Aqun
, p. 5333 - 5344 (2020/09/17)
The mono-dehydration of sugar alcohols such as d-sorbitol and d-mannitol generates 1,4-sorbitan and 1,4-mannitan, respectively, which are relevant platform molecules for the synthesis of detergents and pharmaceuticals. Most reported catalytic systems provided access to di-dehydrated products, while mono-dehydration required special efforts, particularly regarding selectivity and reaction temperature. A series of functionalized yttrium oxides were prepared via sol-gel synthesis in this work, which not only showed an interesting micropipe-like morphology, but also contained functional components. These materials were investigated as photocatalysts in the dehydration of d-sorbitol and d-mannitol, exhibiting high selectivity to mono-dehydration. The effects of solvent, temperature and catalyst were fully discussed. A catalytic mechanism was proposed based on the experimental results and calculations.
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.
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
supporting information, 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.).