Mechanism of oxygenation of naphthoquinone derivative
摘要:
Vitamin K in its hydroquinone form, vitamin KH2, is transformed to vitamin K oxide concurrent with the abstraction of the gamma-hydrogen of Glu leading to Gla. The nonenzymatic model supports that oxygenation of the monoanion of vitamin KH2 can produce the peroxy anion at the 4-position yielding vitamin K oxide. (C) 1998 Elsevier Science Ltd. All rights reserved.
Heterogeneous epoxidation of menadione with hydrogen peroxide over the zeolite imidazolate framework ZIF-8
作者:Irina D. Ivanchikova、Vasilii Yu. Evtushok、Olga V. Zalomaeva、Danil I. Kolokolov、Alexander G. Stepanov、Oxana A. Kholdeeva
DOI:10.1039/d0dt02658a
日期:——
The zeolite imidazolate framework ZIF-8 exhibits superior catalytic performance in the epoxidation of the electron-deficient CC bond in menadione using aqueous hydrogenperoxide as the oxidant. The catalysis has a truly heterogeneous nature and the framework structure remains intact. This is the first example of oxidation catalysis with ZIF-8.
Photochemistry of Epoxynaphthoquinones. 8. Endo-Stereoselective Photocycloaddition of 2,3-Epoxy-2,3-dihydro-2,3-dimethyl-1,4-naphthoquinone to Olefins Containing Amide Group
Irradiation of a benzene solution of 2,3-epoxy-2,3-dihydro-2,3-dimethyl-1,4-naphthoquinone with olefins containing amide group, i.e., N-substituted acrylamides and N-allylcarboxamides predominantly gave the endo-cycloadducts. Upon further irradiation, the cycloadducts underwent photorearrangement to give spirophthalides and alkylidenephthalides.
Tetrabutylammonium Iodide Catalyzed Epoxidation of Naphthoquinone Derivatives with tert-Butyl Hydroperoxide as an Oxidant
作者:Bai-Ru Ai、Xu-Ling Chen、Yu Dong、Lei Tang、Ji-Yu Wang
DOI:10.1055/s-0036-1589035
日期:2017.9
reaction time, and broad substrate scope An efficient and environmentally benign procedure has been developed for the epoxidation of naphthoquinone derivatives by using tetrabutylammonium iodide as a catalyst and tert-butyl hydroperoxide as an oxidant in the presence of silicon dioxide. This protocol, which provides a facile base-free methodology for the synthesis of some new naphthoquinone-based epoxides