4383-05-5Relevant articles and documents
Gold catalysis for selective hydrogenation of aldehydes and valorization of bio-based chemical building blocks
Silva, Rerison J. M.,Fiorio, Jhonatan L.,Vidinha, Pedro,Rossi, Liane M.
, p. 2162 - 2169 (2019/12/30)
Gold catalysts are best known for their selectivity in oxidation reactions, however, there is a promising future for gold in selective hydrogenations. Herein, the hydrogenation of several aldehydes and important bio-based chemical building blocks, namely 5-hydroxymethylfurfural (5-HMF), furfural and vanillin, was performed throughout the combination of Au nanoparticles with Lewis bases. The Au-amine ligand (e.g., 2,4,6-trimethylpyridine) catalytic system could reduce the aldehyde carbonyl group selectively, without reducing alkene moieties or opening the furanic ring that occur on most traditional catalysts. Otherwise, the reduction of nitro group is preferential and the catalytic system was used for the synthesis of furfurylamines, important intermediates in the synthesis of different pharmaceuticals (e.g., furosemide), through the selective reductive amination of furfural starting from nitro-compounds. Moreover, a fully heterogeneous gold catalyst embedded in N-doped carbon (Au@N-doped carbon / TiO2) was able to perform these reactions in successive recycles without the addition of ligands, with impact in the development of a continuous flow process for biomass valorization.
Photoresponsive azo-combretastatin A-4 analogues
Rastogi, Shiva K.,Zhao, Zhenze,Barrett, Scott L.,Shelton, Spencer D.,Zafferani, Martina,Anderson, Hailee E.,Blumenthal, Madeleine O.,Jones, Lindsey R.,Wang, Lei,Li, Xiaopeng,Streu, Craig N.,Du, Liqin,Brittain, William J.
supporting information, p. 1 - 7 (2017/11/24)
Colchicine analogues in which an azo group is incorporated into a molecule containing the key pharmacophore of colchicine, have found particular utility as switchable tubulin binding chemotherapeutics. Combretastatin is a related compound containing a stilbene fragment that shows different bioactivity for the cis and trans isomers. We have performed cell assays on 17 new compounds structurally related to a previously reported azo-analogue of combretastatin. One of these compounds showed enhanced potency against HeLa (IC50 = 0.11 μM) and H157 cells (IC50 = 0.20 μM) for cell studies under 400 nm irradiation and the highest photoactivity (IC50 with irradiation/IC50 in dark = 550). We have performed docking and physicochemical studies of this new compound (7). Kinetic studies in water reveal a longer half-life for the cis isomer of 7 which may be one factor responsible for the better IC50 values in cell assays and the improved photoresponsive behavior.
Water-promoted ortho-selective monohydroxymethylation of phenols in the NaBO2 system
Li, Hui-Jing,Wu, Ying-Ying,Wu, Qin-Xi,Wang, Rui,Dai, Chun-Yang,Shen, Zhi-Lun,Xie, Cheng-Long,Wu, Yan-Chao
, p. 3100 - 3107 (2014/05/06)
Water-promoted ortho-selective monohydroxymethylation of phenols in the NaBO2 system generates salicyl alcohols in 65-97% yields. A remarkable rate-enhancement by water was observed, and NaBO2 appeared to serve the dual role of a suitable base and an efficient chelating reagent. This protocol possesses many advantages such as short reaction times, expanded substrate scope, and high mono- and regio-selectivities. The experimental results were explained by the calculations based on local ionisation energy minima, leading to a possible reaction mechanism.
