1126-76-7Relevant articles and documents
Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds
Li, Siqi,Chen, Xingpeng,Xu, Jiaxi
, p. 1613 - 1620 (2018)
Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular SN2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.
Metal-free epoxidation of alkenes with molecular oxygen and benzaldehyde under visible light irradiation
Tada, Norihiro,Okubo, Hiroaki,Miura, Tsuyoshi,Itoh, Akichika
, p. 3024 - 3026 (2009)
A new convenient metal-free oxidation protocol of a wide variety of alkenes with molecular oxygen and benzaldehyde under visible light irradiation of fluorescent lamp afforded their corresponding epoxides in 49-99% yields. Georg Thieme Verlag Stuttgart.
New molybdenum catalysts for alkyl olefin epoxidation. Their implications for the mechanism of oxygen atom transfer
Mitchell,Finney
, p. 862 - 869 (2001)
We report here the design, synthesis, and characterization of new (dioxo)Mo(VI) epoxidation catalysts based on monoanionic tridentate ligands. Two important features distinguish these catalysts from those previously reported. First, their coordination env
2-Azaadamantane N-oxyl (AZADO)/Cu Catalysis Enables Chemoselective Aerobic Oxidation of Alcohols Containing Electron-Rich Divalent Sulfur Functionalities
Sasano, Yusuke,Kogure, Naoki,Nagasawa, Shota,Kasabata, Koki,Iwabuchi, Yoshiharu
, p. 6104 - 6107 (2018)
The chemoselective oxidation of alcohols containing electron-rich sulfur functionalities (e.g., 1,3-dithianes and sulfides) into their corresponding carbonyl compounds with the sulfur groups can sometimes be a demanding task in modern organic chemistry. A reliable method for this transformation, which features azaadamantane-type nitroxyl radical/copper catalysis using ambient air as the terminal oxidant is reported. The superiority of the developed method was demonstrated by comparing it with various conventional alcohol oxidation methods.
A General Diastereoselective Strategy for Both cis- and trans-2,6-Disubstituted Tetrahydropyrans: Formal Total Synthesis of (+)-Muconin
Srinivas, Beduru,Reddy, D. Srinivas,Mallampudi, N. Arjunreddy,Mohapatra, Debendra K.
, p. 6910 - 6914 (2018)
A protocol for general diastereoselective tandem dihydroxylation followed by SN2 cyclization was developed for the convenient and efficient synthesis of cis- and trans-2,6-disubstituted tetrahydropyrans from ζ-mesyloxy α,β-unsaturated esters. T
Aldehyde-catalyzed epoxidation of unactivated alkenes with aqueous hydrogen peroxide
Kokotos, Christoforos G.,Kokotou, Maroula G.,Lotter, Dominik,Sparr, Christof,Triandafillidi, Ierasia
, p. 10191 - 10196 (2021/08/12)
The organocatalytic epoxidation of unactivated alkenes using aqueous hydrogen peroxide provides various indispensable products and intermediates in a sustainable manner. While formyl functionalities typically undergo irreversible oxidations when activating an oxidant, an atropisomeric two-axis aldehyde capable of catalytic turnover was identified for high-yielding epoxidations of cyclic and acyclic alkenes. The relative configuration of the stereogenic axes of the catalyst and the resulting proximity of the aldehyde and backbone residues resulted in high catalytic efficiencies. Mechanistic studies support a non-radical alkene oxidation by an aldehyde-derived dioxirane intermediate generated from hydrogen peroxide through the Payne and Criegee intermediates.
Organomagnesium Based Flash Chemistry: Continuous Flow Generation and Utilization of Halomethylmagnesium Intermediates
Von Keutz, Timo,Cantillo, David,Kappe, C. Oliver
supporting information, p. 7537 - 7541 (2020/10/12)
The generation of highly unstable chloromethylmagnesium chloride in a continuous flow reactor and its reaction with aldehydes and ketones is reported. With this strategy, chlorohydrins and epoxides were synthesized within a total residence time of only 2.6 s. The outcome of the reaction can be tuned by simply using either a basic or an acidic quench. Very good to excellent isolated yields, up to 97%, have been obtained for most cases (30 examples).
Epoxidation of Alkenes with Molecular Oxygen as the Oxidant in the Presence of Nano-Al 2O 3
Zhou, Xuan,Wang, Qiong,Xiong, Wenfang,Wang, Lu,Ye, Rongkai,Xiang, Ge,Qi, Chaorong,Hu, Jianqiang
supporting information, p. 1789 - 1794 (2020/09/18)
The nano-Al 2O 3-promoted epoxidation of alkenes with molecular oxygen as the oxidant has been developed, providing an efficient route to a variety of epoxides in moderate to excellent yields. The environmentally friendly and efficient nano-Al 2O 3catalyst could be easily recovered and reused five times without significant loss of activity.
