142532-81-8Relevant articles and documents
Electrogenerated Bases. 8. Epoxidations by Electrogenerated Superoxide with/without Auxiliary Carbon Acids. α,β-Unsaturated Ketones
Sugawara, Michio,Baizer, Manuel M.
, p. 4931 - 4934 (1983)
Excellent yields of the epoxides of cyclohexenone (14), 4,4-dimethylcyclohexenone (15), mesityl oxide (17), and benzalacetophenone (18) were obtained by treating the enones contained in the cathode chamber of an electrochemical cell with in situ electrogenerated superoxide in the presence of an auxiliary carbon acid such as diphenylacetonitrile (6) or, better, diethyl methylmalonate (1).Poor or no yields were obtained in the absence of the carbon acid.Products previously prepared by the rection of electrogenerated superoxide with these carbon acids alone were formed here as coproducts.A rationalization is offered for the effectiveness of this methodology and an explanation of the difference between these results and those that had been reported by others using potassium superoxide/18-crown-6 as an epoxidant.
Synthesis of γ,δ-Unsaturated and δ,ε-Unsaturated α-Amino Acids from Fragmentation of γ- and δ-Lactones
Tarver Jr., James E.,Joullie, Madeleine M.
, p. 815 - 820 (2004)
A noncoded amino acid of cyclomarin A (1) was synthesized in a racemic fashion. The method employs a six-membered ring template to control the relative stereochemistry and introduction of the functional groups. Ultimately, Pd-catalyzed fragmentation of the lactone provided γ-δ-unsaturated and δ,ε-unsaturated α-amino acids. A Pd-catalyzed ring opening of a γ-lactone is also reported.
Neighbouring effects on catalytic epoxidation by Fe-cyclam in M2-PDIxCy complexes
Hofmann, Andreas J.,Niederegger, Lukas,Hess, Corinna R.
supporting information, p. 17642 - 17648 (2020/12/30)
The unsymmetric PDIeCy ligand, featuring pyridinediimine and cylam sites, can be selectively metalated. Complementing the diiron compound, we have synthesized two heterobimetallic isomers, [ZnPDIFeCy(PDIeCy)(OTf)4] (3) and [FePDIZnCy(PDIeCy)(OTf)4] (4), and a dizinc complex, [Zn2(PDIeCy)(OTf)4] (5). Olefin epoxidation by the series of complexes was investigated. The M-PDI site influences the reactivity of the M-cyclam, resulting in increased activity toward enones. This journal is
Oxidation of olefins using molecular oxygen catalyzed by a part per million level of recyclable copper catalyst under mild conditions
Yang, Guoqiang,Du, Huiyuan,Liu, Jia,Zhou, Zheng,Hu, Xingbang,Zhang, Zhibing
, p. 675 - 681 (2017/08/14)
Copper catalysts with an imidazole salt tag ([Cu-Imace-R-H][X], X- = F-, Cl-, Br-, I-, CF3CO2-, HSO4-, NO3-, PF6- or BF4-; R = H or CH3) show quite high reactivity for the oxidation of non-aromatic olefins with good selectivity for epoxides. The reactions perform well with a part per million (ppm) catalyst loading at mild temperature and ambient pressure. The highest turnover frequency (TOF) reaches up to 900:000 h-1. The catalytic activity is easy to control by changing the anion of [Cu-Imace-R-H][X]. This catalyst is effective for a series of substrates, including internal and terminal olefins, tri- and tetra-substituted olefins and aromatic olefins. In addition, the copper catalyst can be conveniently separated from the reaction system and reused for at least six cycles without any obvious loss of catalytic activity.
