Rhodium(III)-Catalyzed Directed C−H Amidation of <i>N</i>
-Nitrosoanilines and Subsequent Formation of 1,2-Disubstituted Benzimidazoles
作者:Yanyu Chen、Rong Zhang、Qiujun Peng、Lanting Xu、XianHua Pan
DOI:10.1002/asia.201701287
日期:2017.11.2
An efficient rhodium‐catalyzeddirectC−Hamidation of N‐nitrosoanilines with 1,4,2‐dioxazol‐5‐ones as amidating agents has been developed. This method featured mild reaction conditions, a wide substrate scope and satisfactory yields. Besides, the amidated products could be readily converted to pharmaceutically valuable 1,2‐disubstituted benzimidazoles via an HCl‐mediated deprotection/cyclization process
Rhodium-catalyzed tandem acylmethylation/annulation of <i>N</i>-nitrosoanilines with sulfoxonium ylides for the synthesis of substituted indazole <i>N</i>-oxides
作者:Xin-Feng Cui、Guo-Sheng Huang
DOI:10.1039/d0ob00723d
日期:——
ylides through the rhodium(III)-catalyzed C–H activation and cyclization reaction is described here. This protocol employs nitroso as a traceless directing group. The transformation features powerful reactivity, tolerates various functional groups, and proceeds with moderate to good yields under an ambient atmosphere, providing a straightforward approach to access structurally diverse and valuable indazole
Palladium-catalyzed ortho-acyloxylation of N-nitrosoanilines via direct sp<sup>2</sup> C–H bond activation
作者:Dan-Dan Li、Yi-Xuan Cao、Guan-Wu Wang
DOI:10.1039/c5ob00691k
日期:——
The palladium-catalyzed N-nitroso-directed ortho-acyloxylation of N-nitrosoanilines has been demonstrated via sp2 C–H activation with PhI(OAc)2 as the oxidant and Ac2O/AcOH (1 : 1) or C2H5CO2H as the reaction medium.
Palladium-Catalyzed <i>N</i>-Nitroso-Directed C–H Alkoxylation of Arenes and Subsequent Formation of 2-Alkoxy-<i>N</i>-alkylarylamines
作者:Tingting Gao、Peipei Sun
DOI:10.1021/jo501902d
日期:2014.10.17
A palladium-catalyzed direct ortho-alkoxylation of N-alkyl-N-nitrosoarylamines was developed in which alcohols were used as the alkoxylation reagents and PhI(OAc)2 was employed as the oxidant. The protocol was available for both primary and secondary alcohols. The products were transformed to o-alkoxy-N-alkylanilines expediently by a simple reduction.
Rhodium(III)-Catalyzed<i>N</i>-Nitroso-Directed CH Addition to Ethyl 2-Oxoacetate for Cycloaddition/Fragmentation Synthesis of Indazoles
作者:Jinsen Chen、Pei Chen、Chao Song、Jin Zhu
DOI:10.1002/chem.201404506
日期:2014.10.27
RhIII‐catalyzed N‐nitroso‐directed CH addition to ethyl 2‐oxoacetate allows subsequent construction of indazoles, a privileged heterocycle scaffold in synthetic chemistry, through the exploitation of reactivity between the directing group and installed group. The formal [2+2] cycloaddition/fragmentation reaction pathway identified herein, a unique reactivity pattern hitherto elusive for the N‐nitroso