455-01-6Relevant articles and documents
Anti-Markovnikov alkene oxidation by metal-oxo–mediated enzyme catalysis
Hammer, Stephan C.,Kubik, Grzegorz,Watkins, Ella,Huang, Shan,Minges, Hannah,Arnold, Frances H.
, p. 215 - 218 (2017/10/19)
Catalytic anti-Markovnikov oxidation of alkene feedstocks could simplify synthetic routes to many important molecules and solve a long-standing challenge in chemistry. Here we report the engineering of a cytochrome P450 enzyme by directed evolution to catalyze metal-oxo–mediated anti-Markovnikov oxidation of styrenes with high efficiency. The enzyme uses dioxygen as the terminal oxidant and achieves selectivity for anti-Markovnikov oxidation over the kinetically favored alkene epoxidation by trapping high-energy intermediates and catalyzing an oxo transfer, including an enantioselective 1,2-hydride migration. The anti-Markovnikov oxygenase can be combined with other catalysts in synthetic metabolic pathways to access a variety of challenging anti-Markovnikov functionalization reactions.
Markovnikov-Selective, Activator-Free Iron-Catalyzed Vinylarene Hydroboration
Macnair, Alistair J.,Millet, Clément R. P.,Nichol, Gary S.,Ironmonger, Alan,Thomas, Stephen P.
, p. 7217 - 7221 (2016/10/14)
Two series of structurally related alkoxy-tethered NHC iron(II) complexes have been developed as catalysts for the regioselective hydroboration of alkenes. Significantly, Markonikov-selective alkene hydroboration with HBpin has been controllably achieved using an iron catalyst (11 examples, 35-90% isolated yield) with up to 37:1 branched:linear selectivity. anti-Markovnikov-selective alkene hydroboration was also achieved using HBcat and modification of the ligand backbone (6 examples, 44-71% yields). In both cases, ligand design has enabled activator-free low-oxidation-state iron catalysis.
A novel practical cleavage of tert-butyl esters and carbonates using fluorinated alcohols
Choy, Jason,Jaime-Figueroa, Saul,Lara-Jaime, Teresa
experimental part, p. 2244 - 2246 (2010/05/18)
Thermolytic cleavage of t-butyl esters and t-butyl carbonates was accomplished using TFE (2,2,2-trifluoroethanol) or HFIP (hexafluoroisopropanol) as solvent. Thus, a practical method to cleanly convert t-butyl esters and carbonates into the corresponding carboxylic acids, decarboxylated products, or alcohols in nearly quantitative yields was developed. The product is recovered by a simple solvent evaporation. The practicality of this methodology was demonstrated on alkyl, aryl, and heteroaromatic esters.
