Redox Catalysis of Halide Ion for Formal Cross-dehydrogenative Coupling: Bromide Ion-catalyzed Direct Oxidative α-Acetoxylation of Ketones
作者:Takashi Nagano、Zhenhua Jia、Xingshu Li、Ming Yan、Gui Lu、Albert S. C. Chan、Tamio Hayashi
DOI:10.1246/cl.2010.929
日期:2010.9.5
A novel catalytic approach for formal cross-dehydrogenative coupling using the redox property of bromide ion is reported. Simple bromide salts MBr can work as catalyst for direct oxidative α-acetoxylation of ketones.
Microorganisms that hydrolyzes α-acetoxyacylophenones were screened, and it was found that Pichia miso IAM 4682, a type culture belonging to yeast, gave the best results. The esterase of this microbe hydrolyzed (R)-acetates in a highly enantioselective manner.
polymer-supported 2-monosubstituted 1,3-dithianes from soluble copolymers bearing 1,3-propanedithiol groups, their lithiation, reactions with electrophiles such as aldehydes, ketones, α,β-unsaturated ketones and oxiranes, and cleavage of the produced dithioketal-protected α- or β-hydroxyketones with various reagents have been studied.
The O<sub>2</sub>-Mediated Cross-Dehydrogenative Coupling: Rose Bengal-Catalyzed Direct Oxidative α-Acyloxylation of Ketones
作者:Yunsheng Zhu、Shengjie Song、Lijun Zheng、Jianjun Li
DOI:10.1021/acs.orglett.3c01741
日期:2023.7.7
the direct oxidative α-acyloxylation of ketones using molecularoxygen as the oxidant is developed. This method avoids the use of excessive peroxides and expensive metal catalysts, affording a variety of α-acyloxylated ketones in satisfactory yields. Experimental studies indicate that the reaction proceeds via a radical pathway. Additionally, α-hydroxy ketones could be obtained by changing the solvent