Carbonylative enantioselective meso-desymmetrization of cis-epoxides to trans-β-lactones: effect of salen-ligand electronic variation on enantioselectivity
Metal-Free Oxidative<i>para</i>Cross-Coupling of Phenols
作者:Koji Morimoto、Kazuma Sakamoto、Yusuke Ohnishi、Takeshi Miyamoto、Motoki Ito、Toshifumi Dohi、Yasuyuki Kita
DOI:10.1002/chem.201301028
日期:2013.7.1
Carbonylative enantioselective meso-desymmetrization of cis-epoxides to trans-β-lactones: effect of salen-ligand electronic variation on enantioselectivity
作者:Michael Mulzer、Jessica R. Lamb、Zachary Nelson、Geoffrey W. Coates
DOI:10.1039/c4cc04397a
日期:——
Carbonylation catalysts for the desymmetrization of meso-epoxides yielding enantioenriched trans-β-lactones are reported. Fine-tuning the electronic properties of the ligand further improved enantioselectivity. The sterics of the substrate dictated whether a given electronic variation decreased or increased enantioenrichment, revealing an unexpected relationship between the substrate's steric environment and the electronic nature of the optimal catalyst.
Copper(II) complexes of N3O ligands as models for galactose oxidase: Effect of variation of steric bulk of coordinated phenoxyl moiety on the radical stability and spectroscopy
作者:Cédric Colomban、Christian Philouze、Florian Molton、Nicolas Leconte、Fabrice Thomas
DOI:10.1016/j.ica.2017.09.016
日期:2018.9
the phenoxyl/phenolate redox couple. The one-electron oxidized copper(II)-phenoxyl complexes are mononuclear triplet species, as judged by the ΔMS = 2 resonance in their EPR spectra. The |D| value is estimated at 1700 MHz (axial ZFS). All these radical species exhibit an intense band at 427 nm, which combines the features of both phenoxyl π–π∗ and CT transitions. The stability of the radicals follows