62566-68-1Relevant articles and documents
Synthesis of new chiral Mn(iii)-salen complexes as recoverable and reusable homogeneous catalysts for the asymmetric epoxidation of styrenes and chromenes
Chaudhary, Pooja,Damodaran, Krishna K.,Singh, Surendra,Yadav, Geeta Devi
, p. 1308 - 1318 (2022/02/07)
New chiral Mn(iii)-salen complexes 1a-e and 2a-e were synthesized from the reaction of C2-symmetric chiral salen ligands and Mn(CH3COO)2·4H2O under an inert atmosphere followed by aerobic oxidation. These complexes were obtained in 91-96% yields and characterized by HRMS, FT-IR, UV-visible spectroscopy, TGA, and elemental analysis. The chiral Mn(iii)-salen complexes 1a-e and 2a-e were evaluated in the asymmetric epoxidation of styrene using NaOCl as an oxidant in ethyl acetate as a green solvent. The chiral Mn(iii)-salen complexes 1b and 2b (2 mol%) catalyzed the asymmetric epoxidation of substituted styrenes and chromenes to afford the corresponding epoxides in 95-98% yields with 29-88% ee's. The catalysts 1b and 2b were recovered and reused for up to 2 and 3 runs, respectively, in the asymmetric epoxidation of styrene, and the yield of styrene oxide gradually decreased but the ee was consistent.
Peroxygenase-Catalysed Epoxidation of Styrene Derivatives in Neat Reaction Media
Alcalde, Miguel,Arends, Isabel W. C. E.,Hollmann, Frank,Paul, Caroline E.,Rauch, Marine C. R.,Tieves, Florian
, (2019/08/30)
Biocatalytic oxyfunctionalisation reactions are traditionally conducted in aqueous media limiting their production yield. Here we report the application of a peroxygenase in neat reaction conditions reaching product concentrations of up to 360 mM.
Highly Enantioselective Hydrosilylation of Ketones Catalyzed by a Chiral Oxazaborolidinium Ion
Kang, Byung Chul,Shin, Sung Ho,Yun, Jaesook,Ryu, Do Hyun
supporting information, p. 6316 - 6319 (2017/12/08)
A highly enantioselective hydrosilylation of ketones was developed for the synthesis of a variety of chiral secondary alcohols. In the presence of a chiral oxazaborolidinium ion (COBI) catalyst, the reaction proceeded with good yields (up to 99%) with excellent enantioselectivities (up to 99% ee).