Reactivity of Morita–Baylis–Hillman Adducts in C–H Functionalization of (Hetero)aryl Nitrones: Access to Bridged Cycles and Carbazoles
作者:Ashok Kumar Pandey、Dahye Kang、Sang Hoon Han、Heeyoung Lee、Neeraj Kumar Mishra、Hyung Sik Kim、Young Hoon Jung、Sungwoo Hong、In Su Kim
DOI:10.1021/acs.orglett.8b01910
日期:2018.8.3
nitrones with Morita–Baylis–Hillman (MBH) adducts is described. An allylated intermediate derived from aryl nitrones and MBH adducts allows the formation of bridged cyclic compounds via an exotype [3 + 2] cycloaddition. In sharp contrast, electron-rich indolinyl or aniline substrates were found to couple with MBH adducts to generate naphthalene or carbazole derivatives, respectively.
Rhodium(III)-Catalyzed C–H Activation of Nitrones and Annulative Coupling with Nitroalkenes
作者:Dachang Bai、Qingqian Jia、Teng Xu、Qiuqiu Zhang、Fen Wu、Chaorui Ma、Bingxian Liu、Junbiao Chang、Xingwei Li
DOI:10.1021/acs.joc.7b01574
日期:2017.9.15
Rh(III)-catalyzedsynthesis of nitro-functionalized indenes has been realized via C–Hactivation of arylnitrones and annulation with nitroolefins. The reaction proceeded in moderate to high yields with good functional group tolerance under ambient atmosphere.
Rh(III)-Catalyzed Mild Coupling of Nitrones and Azomethine Imines with Alkylidenecyclopropanes via C–H Activation: Facile Access to Bridged Cycles
作者:Dachang Bai、Teng Xu、Chaorui Ma、Xin Zheng、Bingxian Liu、Fang Xie、Xingwei Li
DOI:10.1021/acscatal.8b00746
日期:2018.5.4
activation of nitrones and azomethine imines in the context of dipolar addition with alkylidenecyclopropanes (ACPs) have been realized. By taking advantage of the ring strain in ACPs, the reaction with aryl nitrones delivered bridged [3.2.1] bicyclicisoxazolidines, and reaction with azomethine imines afforded bridged tricyclic pyrazolones under the same conditions, where both the nitrone and azomethine
2,2,2-Trifluoroacetaldehyde <i>O</i>-(Aryl)oxime: A Precursor of Trifluoroacetonitrile
作者:Bo Lin、Yunfei Yao、Yangjie Huang、Zhiqiang Weng
DOI:10.1021/acs.orglett.2c00637
日期:2022.3.18
The preparation of 2,2,2-trifluoroacetaldehyde O-(aryl)oxime, a previously inaccessible precursor of trifluoroacetonitrile, via reaction of hydroxylamine and trifluoroacetaldehyde hydrate is reported. This precursor released CF3CN in quantitative yield under mildly basic conditions. The precursor was successfully used in the synthesis of trifluoromethylated oxadiazoles. The facile, cost-effective,
Nitrone Directing Groups in Rhodium(III)-Catalyzed C−H Activation of Arenes: 1,3-Dipoles versus Traceless Directing Groups
作者:Fang Xie、Songjie Yu、Zisong Qi、Xingwei Li
DOI:10.1002/anie.201609658
日期:2016.12.5
Functionalizable directing groups (DGs) are highly desirable in C−H activation chemistry. The nitrone DGs are explored in rhodium(III)‐catalyzedC−H activation of arenes and couplings with cyclopropenones. N‐tert‐butyl nitrones bearing a small ortho substituent coupled to afford 1‐naphthols, where the nitrone acts as a traceless DG. In contrast, coupling of N‐tert‐butyl nitrones bearing a bulky ortho