82911-78-2Relevant articles and documents
L-serine-functionalized montmorillonite decorated with Au nanoparticles: A new highly efficient catalyst for the reduction of 4-nitrophenol
Rocha, Mariana,Costa, Paula,Sousa, Carlos A.D.,Pereira, Clara,Rodríguez-Borges, José E.,Freire, Cristina
, p. 143 - 155 (2018)
The conversion of nitroarenes to aminoarenes is of great industrial interest since they are prevalent pollutants in water and aminoarenes are important intermediates in the synthesis of pharmaceuticals, natural products and in bulk chemical production. In this work, two new catalysts for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) were prepared by immobilization of gold nanoparticles onto the surface of K10 montmorillonite clay (K10) functionalized with two new L-serine derivative organosilanes. Transmission electron microscopy showed the presence of 4–5 nm gold nanoparticles after catalysis. The reduction reaction of 4-NP to 4-AP at 25 °C, using NaBH4 as reducing agent, led to nearly 100% conversion in only 1 minute, presenting pseudo-first-order rate constants normalized for Au loading of K = 630 and 430 mmol?1 s?1. The catalysts showed high stability, leading to substrate conversions of 95–100% after 10 consecutive cycles, with negligible Au leaching.
Exploration of the Fluoride Reactivity of Aryltrifluoroborate on Selective Cleavage of Diphenylmethylsilyl Groups
Fujiki, Katsumasa,Tanaka, Katsunori
supporting information, p. 4616 - 4620 (2020/07/06)
The first known report on the fluoride catalytic reactivity of potassium aryltrifluoroborate is described. The fluoride reactivity of phenyltrifluoroborate was controlled by substituents on the trifluoroborate-attached benzene, such as the methoxy group a
Sterically Hindered 2,4,6-Tri- tert-butylpyridinium Salts as Single Hydrogen Bond Donors for Highly Stereoselective Glycosylation Reactions of Glycals
Ghosh, Titli,Mukherji, Ananya,Kancharla, Pavan K.
supporting information, p. 3490 - 3495 (2019/05/24)
We demonstrate here that the strained and bulky protonated 2,4,6-tri-tert-butylpyridine salts serve as efficient catalysts for highly stereoselective glycosylations of various glycals. Moreover, the mechanism of action involves an interesting single hydrogen bond mediated protonation of glycals and not via the generally conceived Br?nsted acid pathway. The counteranions also play a role in the outcome of the reaction.