Iron-Catalyzed Cyclization of Nitrones with Geminal-Substituted Vinyl Acetates: A Direct [4 + 2] Assembly Strategy Leading to 2,4-Disubstituted Quinolines
作者:Mingbing Zhong、Song Sun、Jiang Cheng、Ying Shao
DOI:10.1021/acs.joc.6b01910
日期:2016.11.18
An iron-catalyzed intermolecular [4 + 2] cyclization of arylnitrones with geminal-substituted vinyl acetates was developed for the synthesis of 2,4-disubstituted quinolines in moderate to good yields with good functional group compatibilities. Preliminary mechanistic studies suggest a plausible iron-catalyzed C–H activation process under external-oxidant-free conditions.
Rh(III)-Catalyzed C–H Cyclization of Arylnitrones with Diazo Compounds: Access to 3-Carboxylate Substituted<i>N</i>-Hydroxyindoles
作者:Yazhou Li、Jian Li、Xiaowei Wu、Yu Zhou、Hong Liu
DOI:10.1021/acs.joc.7b01393
日期:2017.9.1
Recently, N-hydroxyindole derivatives have received much interest because of their unique structural motif and various biological activities. In this study, we report the first example of a Rh(III)-catalyzed reaction of arylnitrones with α-diazoketoesters or α-diazodiketones to produce N-hydroxyindole derivatives. Intriguingly, we could build the N-hydroxyindole scaffold by blocking the cleavage of
Rhodium-Catalyzed CH Annulation of Nitrones with Alkynes: A Regiospecific Route to Unsymmetrical 2,3-Diaryl-Substituted Indoles
作者:Hao Yan、Haolong Wang、Xincheng Li、Xiaoyi Xin、Chunxiang Wang、Boshun Wan
DOI:10.1002/anie.201503997
日期:2015.9.1
of anilines or related compounds with internal alkynes provides straightforward access to 2,3‐disubstituted indole products. However, this transformation proceeds with poor regioselectivity in the synthesis of unsymmetrically 2,3‐diaryl substituted indoles. Herein, we report the rhodium(III)‐catalyzed CH annulation of nitrones with symmetrical diaryl alkynes as an alternative method to prepare 2,
Trimethylsilyl chloride promoted synthesis of α-branched amines by nucleophilic addition of organozinc halides to nitrones
作者:Ying Fu、Yanhua Liu、Yaojuan Chen、Helmut M. Hügel、Minzhu Wang、Danfeng Huang、Yulai Hu
DOI:10.1039/c2ob26202a
日期:——
general procedure for the nucleophilicaddition of organozinc halides with nitrones in the presence of trimethylsilyl chloride has been developed. Trimethylsilyl chloride was found to be both an indispensable reaction promoter and a ready hydroxylamine protective agent in these reactions. The produced O-(trimethylsilyl)hydroxylamines can be easily reduced into corresponding amines just by a zinc–copper
One-Pot Enol Silane Formation/Mukaiyama-Mannich Addition of Ketones, Amides, and Thioesters to Nitrones in the Presence of Trialkylsilyl Trifluoromethanesulfonates
作者:C. Wade Downey、Carolyn M. Dombrowski、Erin N. Maxwell、Chelsea L. Safran、Odamea A. Akomah
DOI:10.1002/ejoc.201300691
日期:2013.9
Ketones, amides, and thioesters form enolsilanes and add to N-phenylnitrones in one pot in the presence of trimethylsilyl trifluoromethanesulfonate and trialkylamine. The reaction is general to a range of silyl trifluoromethanesulfonates and N-phenylnitrones. The β-(silyloxy)amino carbonyl products are stable to chromatography and can be isolated in 63–99 % yield.