We report the synthesis of derivatives of vitamin K3 as well as of vitaminsK1 and K2 containing a different number of methyl groups in various positions in order to reduce their redox potentials and to change systematically their steric features. The long aliphatic chain of vitaminsK1 and K2 is simulated by an undecyl chain or a methyl group, respectively. The redox potentials of the first reduction
Activated Carbon-Promoted Dehydrogenation of Hydroquinones to Benzoquinones, Naphthoquinones, and Anthraquinones under Molecular Oxygen Atmosphere
作者:Sanghun Kim、Ryosuke Matsubara、Masahiko Hayashi
DOI:10.1021/acs.joc.8b02961
日期:2019.3.1
that the activated carbon-molecular oxygen system promotes the conversion of hydroquinones to benzoquinones, naphthoquinones, and anthraquinones, which are often found in natural products and pharmaceuticals. In particular, the one-potsynthesis of naphthoquinones and anthraquinones involving a Diels-Alder reaction is a useful protocol for this purpose.
Bismuth-catalyzed methylation and alkylation of quinone derivatives with tert-butyl peroxybenzoate as an oxidant
作者:Jian Yang、Yu Dong、Shuai He、Zhi-Chuan Shi、Yu Wang、Ji-Yu Wang
DOI:10.1016/j.tet.2019.130729
日期:2019.12
radical reaction mechanism. Particularly, TBPB was used not only as an efficient oxidant, but also as a green methyl source in such transformation. Moreover, this method could also be efficiently extended to the alkylation of quinones. This reaction tolerated a series of functional groups and prepared a series of derivatives of vitamin K3 and benzoquinone. Notably, antimalarial parvaquone was synthesized