Selective hydrogenation of unsaturated compounds is mainly carried out by using high-pressure hydrogen in the presence of a precious or transition metal catalyst. Here, we describe a benign approach to efficiently catalyze the hydrogenation of furfural (FUR) to furfuryl alcohol (FFA) over commercially available cesium carbonate using nontoxic and cheap polymethylhydrosiloxane (PMHS) as hydrogen source. Good to excellent FFA yields (≥90%) could be obtained at 25-80 °C by appropriate control of the catalyst dosage, reaction time, and the hydride amount. FUR-to-FFA hydrogenation was clarified to follow a pseudo-first order kinetics with low apparent activation energy of 20.6 kJ mol. Mechanistic insights manifested that PMHS was redistributed to HSiMe, which acted as the active silane for the hydrogenation reactions. Importantly, this catalytic system was able to selectively reduce a wide range of aromatic aldehydes to the corresponding alcohols in good yields of 81-99% at 25-80 °C in 2-6 h.
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http://dx.doi.org/10.1039/c8ra08616h | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Instytut Chemii Organicznej PAN: Instytut Chemii Organicznej Polskiej Akademii Nauk, Institute of Organic Chemistry, Kasprzaka 44/52, 01-224, Warsaw, POLAND.
The development of straightforward synthetic methods for photoactive polycyclic aromatic hydrocarbons (PAHs) that avoid Pd-catalyzed or radical-based processes remains a challenge. Such methods are essential to reducing the cost and environmental impact of organic photodevices. In this work, we present a one-pot synthetic approach for creating novel bipolar PAHs with extended π-conjugation, which are not accessible via conventional Pd-catalyzed routes.
View Article and Find Full Text PDFChemistry
December 2024
Laboratory of Catalysis, MolSys Research Unit, Université de Liège, Institut de Chimie Organique (B6a), Allée du six Août 13, 4000, Liège, Belgium.
Thirteen imidazolium iodides bearing benzyl, mesityl, or 2,6-diisopropylphenyl substituents on their nitrogen atoms, and C-C alkyl chains on their C2 carbon atom were readily deuterated with DO as a cheap and non-toxic deuterium source in the presence of CsCO, a weak, innocuous, inorganic base. The isotopic exchange proceeded quickly and efficiently under mild, aerobic conditions to afford a range of aNHC and NHO precursors regioselectively labeled on their C2α exocyclic position and/or C4=C5 heterocyclic backbone. A "carbene-free" mechanism was postulated, in which the carbonate anion acts as a catalyst to activate an exocyclic, acidic C-H bond and ease a deuterium transfer from DO to the imidazolium salt in a concerted fashion.
View Article and Find Full Text PDFOrg Biomol Chem
December 2024
Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361001, Fujian, People's Republic of China.
A novel and transition-metal-free hydrophosphinylation of allenes with secondary phosphine oxides was developed. In the presence of the cheap and commercially available cesium carbonate, various hydrophosphinylation products were synthesized with exclusive regio- and stereoselectivity under mild conditions. This methodology provides simple and efficient access to ()-alkenylphosphine oxides in moderate to excellent yields with a relatively broad substrate scope.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
December 2024
Materiales Polifuncionales Basados en Carbono (UGR-Carbon), Dpto. Química Inorgánica - Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente - Universidad de Granada (UEQ-UGR), ES18071, Granada, Spain.
J Org Chem
December 2024
Department of Chemistry, University of Idaho, Moscow, Idaho 83844, United States.
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