4426-63-5Relevant articles and documents
Switchable asymmetric bio-epoxidation of α,β-unsaturated ketones
Liu, Yu-Chang,Wu, Zhong-Liu
supporting information, p. 1158 - 1161 (2016/01/15)
Efficient asymmetric bio-epoxidation of electron-deficient α,β-unsaturated ketones was realized via a tandem reduction-epoxidation-dehydrogenation cascade, which proceeds in a switchable manner to afford either chiral epoxy ketones or allylic epoxy alcoho
Enantioselective epoxidation with chiral MnIII(salen) catalysts: Kinetic resolution of aryl-substituted allylic alcohols
Adam,Humpf,Roschmann,Saha-Moeller
, p. 5796 - 5800 (2007/10/03)
A set of aryl-substituted allylic alcohols rac-2 has been epoxidized by chiral Mn(salen*) complexes 1 as the catalyst and iodosyl benzene (PhIO) as the oxygen source. Whereas one enantiomer of the allylic alcohol 2 is preferentially epoxidized to give the threoor cis-epoxy alcohol 3 (up to 80% ee) as the main product (dr up to >95:5), the other enantiomer of 2 is enriched (up to 53% ee). In the case of 1,1-dimethyl-1,2-dihydronaphthalen-2-ol (2c), the CH oxidation to the enone 4c proceeds enantioselectively and competes with the epoxidation. The absolute configurations of the allylic alcohols 2 and their epoxides 3 have been determined by chemical correlation or CD spectroscopy. The observed diastereo- and enantioselectivities in the epoxidation reactions are rationalized in terms of a beneficial interplay between the hydroxy-directing effect and the attack along the Katsuki trajectory.
Carbodiimide-Promoted Olefin Epoxidation with Aqueous Hydrogen Peroxide
Majetich, George,Hicks, Rodgers,Sun, Guang-Ri,McGill, Patrick
, p. 2564 - 2573 (2007/10/03)
Commercially available carbodiimides in hydroxylic solvents containing hydrogen peroxide with mildly basic or acidic catalysts have been found to promote the epoxidation of olefins. A commercially available 30% aqueous solution of hydrogen peroxide serves as the oxidant for this process. The presumed reactive species is a peroxyisourea generated in situ by the addition of hydrogen peroxide to the carbodiimide.