3041-16-5Relevant articles and documents
Nanotitania catalyzes the chemoselective hydration and alkoxylation of epoxides
Ballesteros–Soberanas, Jordi,Leyva–Pérez, Antonio,Martínez–Castelló, Aarón,Oliver–Meseguer, Judit,Tejeda–Serrano, María
, (2021/10/12)
Glycols and ethoxy– and propoxy–alcohols are fundamental chemicals in industry, with annual productions of millions of tons, still manufactured in many cases with corrosive and unrecoverable catalysts such as KOH, amines and BF3?OEt2. Here we show that commercially available, inexpensive, non–toxic, solid and recyclable nanotitania catalyzes the hydration and alkoxylation of epoxides, with water and primary and secondary alcohols but not with phenols, carboxylic acids and tertiary alcohols. In this way, the chemoselective synthesis of different glycols and 1,4–dioxanones, and the implementation of nanotitania for the production in–flow of glycols and alkoxylated alcohols, has been achieved. Mechanistic studies support the key role of vacancies in the nano–oxide catalyst.
Flavin Nitroalkane Oxidase Mimics Compatibility with NOx/TEMPO Catalysis: Aerobic Oxidization of Alcohols, Diols, and Ethers
Thapa, Pawan,Hazoor, Shan,Chouhan, Bikash,Vuong, Thanh Thuy,Foss, Frank W.
, p. 9096 - 9105 (2020/08/14)
Biomimetic flavin organocatalysts oxidize nitromethane to formaldehyde and NOx - providing a relatively nontoxic, noncaustic, and inexpensive source for catalytic NO2 for aerobic TEMPO oxidations of alcohols, diols, and ethers. Alcohols were oxidized to aldehydes or ketones, cyclic ethers to esters, and terminal diols to lactones. In situ trapping of NOx and formaldehyde suggest an oxidative Nef process reminiscent of flavoprotein nitroalkane oxidase reactivity, which is achieved by relatively stable 1,10-bridged flavins. The metal-free flavin/NOx/TEMPO catalytic cycles are uniquely compatible, especially compared to other Nef and NOx-generating processes, and reveal selectivity over flavin-catalyzed sulfoxide formation. Aliphatic ethers were oxidized by this method, as demonstrated by the conversion of (-)-ambroxide to (+)-sclareolide.
Oxidative lactonization of diethylene glycol to high-value-added product 1,4-dioxan-2-one promoted by a highly efficacious and selective catalyst ZnO-ZnCr2O4
Cai, Menglu,Wang, Xiaozhong,Chen, Yingqi,Dai, Liyan
, (2019/09/30)
For the first time, the desired product 1,4-dioxan-2-one (PDO) was successfully synthesized via the oxidative lactonization of diethylene glycol (DEG) under mild conditions. After screening several catalysts (M-Cr-O), we found ZnO-ZnCr2O4 (Zn-Cr-O) catalyst exhibited excellent catalytic performance and this chemical transformation obtained moderate to excellent selectivity (96.22%) and conversion (81.95%) within a 4 h reaction time. Subsequently, the morphology of calcined M-Cr-O was investigated by FT-IR, XRD, FESEM, TEM, and N2 adsorption-desorption tests for further study on catalytic performances. The strength and quantity of acid and base sites over Zn-Cr-O were also detected by NH3-TPD and CO2-TPD, and it was worth noting that the acid/base sites over ZnO-ZnCr2O4 (Zn-Cr-O) catalyst could promote this catalytic process well. Recycle studies demonstrated exceptional stability and recyclability of the prepared catalyst without significant efficiency and selectivity loss after 10 consecutive cycles.
