Heterogeneous Suzuki–Miyaura coupling of heteroaryl ester <i>via</i> chemoselective C(acyl)–O bond activation
作者:Hongpeng Ma、Chaolumen Bai、Yong-Sheng Bao
DOI:10.1039/c9ra02394a
日期:——
A site-selective supported palladium nanoparticle catalyzed Suzuki–Miyaura cross-coupling reaction with heteroaryl esters and arylboronic acids as coupling partners was developed. This methodology provides a heterogeneous catalytic route for aryl ketone formation via C(acyl)–O bond activation of esters by successful suppression of the undesired decarbonylation phenomenon. The catalyst can be reused
secondary benzylic alcohols via tandem Ni-catalyzed cross-coupling reactions of aromatic 2-pyridyl esters with alkyl zinc reagents and carbonyl group reduction by Ni–H species is achieved. Preliminary mechanistic studies reveal that the Ni–H species is generated in situ via β-hydride elimination of the Negishi reagents. The reaction is catalyzed by bench-stable nickel salts under mild conditions with
A novel metal- and catalyst-free dearomative reaction of 2-oxypyridines to construct gem-difluoromethylenated N-substituted 2-pyridones has been developed. The reaction involves an attractive acyl rearrangement from O to CF2 of difluorocarbene-derived pyridinium ylides, which provides a new strategy for the direct introduction of the gem-difluoromethylene group with high efficiency and selectivity as
Nickel-catalyzed reductive coupling of arylcarboxylic acid 2-pyridyl esters with alkyl methanesulfonates: access to alkyl aryl ketones
作者:Hang Yu、Zhong-Xia Wang
DOI:10.1039/d3ob00293d
日期:——
Alkyl aryl ketones were synthesized via a nickel-catalyzed reductive coupling reaction of arylcarboxylic acid (2-pyridyl)esters with primary and secondary alkylmethanesulfonates under mild reaction conditions. This method suits a wide range of substrates and shows good compatibility with functional groups.