An efficient Fe(OTf)3-catalyzed nucleophilicsubstitution of cyclic or acyclic tertiary alcohols with difluoroenoxysilanes is developed, which provides a facile protocol for assembling structurally diverse α,α-gem-difluoroketones featuring a quaternary carbon center in good to excellent yields under mild conditions. Moreover, the diverse product elaborations highlight the utility of this protocol,
Synthesis of 3-hydroxyoxindoles by Pd-catalysed intramolecular nucleophilic addition of aryl halides to α-ketoamides
作者:Yi-Xia Jia、Dmitry Katayev、E. Peter Kündig
DOI:10.1039/b917958e
日期:——
Pd/PtBu(3)-catalysed intramolecularnucleophilic addition of arylhalides to alpha-ketoamides in the presence of nBuOH and base has been realized with high yields, providing a new, direct, and efficient synthetic strategy to obtain 3-hydroxyoxindoles.
Nickeleophilic addition! The first example of a nickel‐catalyzed direct intramolecular nucleophilic addition of aryl or vinyl chlorides to α‐ketoamides throughCCl bondactivation is reported, which takes place under mild reaction conditions (see scheme).
An enantioconvergent substitution of 3-substituted 3-chlorooxindoles with N-aryl glycines under visible light irradiation is reported. A transition-metal-free cooperative catalysis platform with a dicyanopyrazine-derived chromophore (DPZ) as a photoredox catalyst and a chiral Brønsted acid catalyst is effective for these transformations, which involve a single-electron transfer redox step and an enantioselective
Palladium-Catalyzed Allylation of Cyclopropyl Acetylenes with Oxindoles to Construct 1,3-Dienes
作者:Chuan-Jun Lu、Xin Yu、Yu-Ting Chen、Qing-Bao Song、Zhen-Ping Yang、Hong Wang
DOI:10.1002/ejoc.201901536
日期:2020.2.14
A novel palladium‐catalyzed allylic alkylation of oxindoles with cyclopropylacetylenes has been developed. Various 1,3‐diene oxindole framework bearing a quaternary stereocenter at the C3 position were synthesized straightforwardly in good to excellent yields with high regio‐, and stereoselectivities.