For the enantioselective borohydride reduction of carbonyl compounds catalyzed by the optically active ketoiminatocobalt complexes, chloroform has been employed as a unique solvent for achieving a high enantioselectivity, whereas it was found that a catalytic amount of chloroform effectively activated the present catalytic system to convert various ketones into the corresponding reduced product with a high ee in the THF solvent.
Free radical-promoted one carbon ringexpansion and chain extension of 1,3-diketones including 1,3-diarylpropane-1,3-diones and 2-aroyl-3,4-dihydro-2H-naphalen-1-one to generate corresponding 1,4-diketones are described.
Copper-catalyzed methylation of 1,3-diketones with tert-butyl peroxybenzoate
作者:Zhi-Hao Zhou、Cheng-Kun Li、Shao-Fang Zhou、Adedamola Shoberu、Jian-Ping Zou
DOI:10.1016/j.tet.2017.03.058
日期:2017.5
Copper-catalyzed radical methylation of 1,3-diketones with tert-butyl peroxybenzoate in air is described, providing a general pathway to α-methyl 1,3-diketones in moderate to good yields. This protocol has been scaled up to 50 g, and one of the synthesized products can be used in the synthesis of medicine, Rosuvastatin.
[reaction: see text] The reductive desymmetrization of acyclic 1,3-diketones was achieved for the first time by catalytic borohydride reduction in the presence of opticallyactive beta-ketoiminato cobalt(II) complex catalysts. In this reaction, various 2-substituted-1,3-diaryl-1,3-propanediones were converted into the corresponding opticallyactive 2-substituted-1,3-diaryl-3-hydroxypropanone in good-to-high