- Rhodium(iii)-catalyzed asymmetric [4+1] spiroannulations of: O -pivaloyl oximes with α-diazo compounds
-
Chiral RhIII catalysts can catalyze the asymmetric [4+1] spiroannulation of O-pivaloyl oximes with α-diazo homophthalimides under redox-neutral and acid/base-neutral conditions, leading to formation of chiral spirocyclic imines as a result of C-H activation and N-O cleavage. The reaction proceeded with high efficiency and features broad substrate scope, mild reaction conditions, and high to excellent enantioselectivities. This journal is
- Chang, Junbiao,Deng, Wei-Qiao,Kong, Lingheng,Li, Xingwei,Liu, Bingxian,Sun, Lincong,Wang, Fen,Zhao, Yanlian
-
supporting information
p. 8268 - 8271
(2021/08/25)
-
- Redox-Neutral Access to Isoquinolinones via Rhodium(III)-Catalyzed Annulations of O-Pivaloyl Oximes with Ketenes
-
A mild and redox-neutral [4 + 2] annulation of O-pivaloyl oximes with ketenes has been realized for synthesis of quaternary-carbon-stereocenter-containing (QCSC) isoquinolinones, where the N-OPiv not only acts as an oxidizing group but also offers coordination saturation to inhibit protonolysis. The reaction mechanism has been studied by DFT calculations.
- Yang, Xifa,Liu, Song,Yu, Songjie,Kong, Lingheng,Lan, Yu,Li, Xingwei
-
supporting information
p. 2698 - 2701
(2018/05/22)
-
- Methyl ketone oxime esters as nucleophilic coupling partners in Pd-catalyzed C-H alkylation and application in the synthesis of isoquinolines
-
Methyl ketone oxime esters have been found to be excellent coupling partners for C(sp2)-C(sp3) bond formation via Pd-catalyzed aromatic C-H activation. This transformation forms the basis of an approach to regioselectively synthesize substituted isoquinolines via coupling with aryloxime esters. Our mechanistic studies suggested that the reaction proceeded through Pd(II)-catalyzed aromatic C-H activation, tautomerization, and a 1,3-shift of the palladacycle-ligated methyl ketone oxime ester to enable the C-C bond formation by reductive elimination, and intramolecular condensation of an imido-Pd(II) intermediate to form the heterocycle. The aryloxime group not only was used as a directing group for Pd-catalyzed aromatic C-H activation but also functioned as an internal oxidant to allow the reaction to be redox-neutral. Our study illuminated the scope and limitations of this C-H alkylation process, which may serve as the point of departure for developing other C-H functionalization reactions using oxime esters and potentially other carbonyl derivatives as the nucleophilic coupling partners.
- Zhang, Zhi-Wei,Lin, Aijun,Yang, Jiong
-
p. 7041 - 7050
(2014/08/18)
-