Building Congested Ketone: Substituted Hantzsch Ester and Nitrile as Alkylation Reagents in Photoredox Catalysis
作者:Wenxin Chen、Zheng Liu、Jiaqi Tian、Jin Li、Jing Ma、Xu Cheng、Guigen Li
DOI:10.1021/jacs.6b06379
日期:2016.9.28
For the first time, 4-alkyl Hantzsch esters were used to construct molecules with all-carbon quaternary centers by visible light-induced photoredox catalysis via transfer alkylation. Up to a 1500 h(-1) turnover frequency was achieved in this reaction. Reactions of 4-alkyl Hantzsch nitriles as tertiary radical donors joined two contiguous all-carbon quaternary centers intermolecularly, and this chemistry
Iron-Catalyzed Acyl Migration of Tertiary α-Azidyl Ketones: Synthetic Approach toward Enamides and Isoquinolones
作者:Tonghao Yang、Xing Fan、Xiaopeng Zhao、Wei Yu
DOI:10.1021/acs.orglett.8b00409
日期:2018.4.6
transformed into enamides by treatment with FeBr2 at elevated temperature in DMF. The reaction proceeds via 1,2-benzoyl migration from α-carbon to the nitrogen atom, accompanied by expulsion of a nitrogen molecule. This protocol is suitable for the synthesis of N-(cyclopent-1-en-1-yl)benzamides, N-(cyclohex-1-en-1-yl)benzamides, and N-benzoyl-α-methyl enamines and provides a convenient approach toward isoquinolones
Intermolecular C–H Quaternary Alkylation of Aniline Derivatives Induced by Visible-Light Photoredox Catalysis
作者:Jie Cheng、Xia Deng、Guoqiang Wang、Ying Li、Xu Cheng、Guigen Li
DOI:10.1021/acs.orglett.6b02179
日期:2016.9.16
The intermolecular direct C–H alkylation of aniline derivatives with α-bromo ketones to build a quaternary carbon center was reported with a visible-light catalysis procedure. The reaction covers a variety of functional groups with good to excellent yields. A regioselectivity favoring the ortho position for the amine group was observed and investigated with Fukui indices and spectral methods.
Visible‐Light‐Enabled Enantioconvergent Synthesis of α‐Amino Acid Derivatives via Synergistic Brønsted Acid/Photoredox Catalysis
作者:Chao Che、Yi‐Nan Li、Xiang Cheng、Yi‐Nan Lu、Chun‐Jiang Wang
DOI:10.1002/anie.202012909
日期:2021.2.23
An unprecedented radical cross‐coupling reaction was achieved between glycine esters and racemic α‐bromoketones catalyzed by synergistic Brønsted acid/photoredox catalysis, thus serving as an efficient platform for the synthesis of highly valuable enantioenriched unnatural α‐aminoacid derivatives. This dual catalysis provides a powerful capability to control the reactive radical intermediate and iminium
A Synthetic Approach to Tetrasubstituted Alkenes: Using β-Carbonyl Benzothiazol-2-yl Sulfones as Electrophiles
作者:Song Ou、Chun-Ru Cao、Min Jiang、Jin-Tao Liu
DOI:10.1002/ejoc.201301021
日期:2013.10
A novel olefination method based on the modified Julia olefination reaction was developed. The reactions of β-carbonyl benzothiazol-2-yl sulfones with a series of alkynyllithiums and TMSCN gave the corresponding β-alkoxy sulfone intermediates, which underwent facile Smiles rearrangement and spontaneous elimination to yield tetrasubstituted enynes and cyanoalkenes, respectively.
开发了一种基于改进的 Julia 烯化反应的新烯化方法。β-羰基苯并噻唑-2-基砜与一系列炔基锂和 TMSCN 反应得到相应的 β-烷氧基砜中间体,该中间体经过简单的 Smiles 重排和自发消除,分别产生四取代的烯炔和氰基烯烃。