Epoxidation of Olefins with a Silica-Supported Peracid
作者:Rossella Mello、Ana Alcalde-Aragonés、María Elena González Núñez、Gregorio Asensio
DOI:10.1021/jo300533b
日期:2012.8.3
Anhydrous [2-percarboxyethyl] functionalized silica (2a) is an advantageous oxidant for performing the epoxidation of olefins 1. Epoxides 3 do not undergo the ring-opening reactions catalyzed by the acidic silica surface, except for particularly activated cases such as styrene oxide. The hydrophilic and acidic character of the silica surface does not interfere with the directing effects exerted by
Deracemization of (±)-2,3-disubstituted oxiranes via biocatalytic hydrolysis using bacterial epoxide hydrolases: kinetics of an enantioconvergent process
作者:Wolfgang Kroutil、Martin Mischitz、Kurt Faber
DOI:10.1039/a704812b
日期:——
Asymmetric biocatalytichydrolysis of (±)-2,3-disubstituted oxiranes leading to the formation of vicinal diols in up to 97% ee at 100% conversion was accomplished by using the epoxide hydrolase activity of various bacterial strains. The mechanism of this deracemization was elucidated by 18OH2-labelling experiments using a partially purified epoxide hydrolase from Nocardia EH1. The reaction was shown
Epoxidation of Olefins with a Silica-Supported Peracid in Supercritical Carbon Dioxide under Flow Conditions
作者:Rossella Mello、Ana Alcalde-Aragonés、Andrea Olmos、María Elena González-Núñez、Gregorio Asensio
DOI:10.1021/jo300532f
日期:2012.5.18
2-percarboxyethyl-functionalized silica (2b), a recyclable supported peracid, is a suitable reagent to perform the epoxidation of alkenes 1 in supercriticalcarbondioxide at 250 bar and 40 °C underflowconditions. This procedure simplifies the isolation of the reaction products and uses only carbondioxide as a solvent under mild conditions. The solid reagent 2b can be easily recycled by a reaction with
Boronic Acid Catalyzed Regioselective Aminolysis of 3,4-Epoxy Alcohols
作者:Jiawei Liu、Hongqing Yao、Chuan Wang
DOI:10.1021/acscatal.8b02591
日期:2018.10.5
homoallylic alcohols has been accomplished, which was catalyzed by a commercially available boronic acid. Due to the directing effect of the hydroxyl moiety, the ring opening reaction of a variety of 3,4-epoxy alcohols bearing different substitution patterns with various aromatic amines as nucleophiles proceeded in a stereospecific reaction pathway at the C-3 position furnishing various amino alcohols as products