Stereospecific Electrophilic Fluorocyclization of α,β-Unsaturated Amides with Selectfluor
作者:Haiyang Fei、Zheyuan Xu、Hongmiao Wu、Lin Zhu、Hitesh B. Jalani、Guigen Li、Yao Fu、Hongjian Lu
DOI:10.1021/acs.orglett.0c00620
日期:2020.4.3
An efficient fluorocyclization of α,β-unsaturated amides through a formal halocyclization process is developed. The reaction proceeds undertransition-metal-freeconditions and leads to the formation of fluorinated oxazolidine-2,4-diones with excellent regio- and diastereoselectivity. The evaluation of the reaction mechanism based on preliminary experiments and density functional theory calculations
Pd-Catalyzed Carbonylation of Vinyl Triflates To Afford α,β-Unsaturated Aldehydes, Esters, and Amides under Mild Conditions
作者:Shaoke Zhang、Helfried Neumann、Matthias Beller
DOI:10.1021/acs.orglett.9b00765
日期:2019.5.17
An efficient and general protocol for the synthesis of α,β-unsaturated aldehydes, esters, and amides via carbonylation of vinyl triflates including derivatives of camphor, ketoisophorone, verbenone, and pulegone was developed. Crucial for these transformations is the use of a specific palladium catalyst containing a pyridyl-substituted dtbpx-type ligand. This procedure also allows for an easy access
开发了一种有效的通用方案,可通过乙烯基三氟甲磺酸酯的羰基化反应合成α,β-不饱和醛,酯和酰胺,包括樟脑,酮异佛尔酮,马鞭草酮和普乐酮。这些转化的关键是使用含有吡啶基取代的d t bpx型配体的特定钯催化剂。该方法还使得容易从相应的酮获得二羰基化产物。
Ligand‐Controlled, Tunable Copper‐Catalyzed Radical Divergent Trifluoromethylation of Unactivated Cycloalkenes
作者:Qi Wang、Zhong‐Lin Zang、Mi Jie、Li‐Hua Luo、Dan Yang、Cheng‐He Zhou、Gui‐Xin Cai
DOI:10.1002/adsc.202101016
日期:2021.12.7
The Cu-catalyzed high-chemoselective trifluoromethylation reactions of unactivated cycloalkenes via the modulation of appropriate ligands have been explored. The Cu(I)/appropriate ligands-catalytic systems overcome the key challenge in differentiating two pathways involving radical intermediates and provide a ligand-controlled approach for site-specific spiro-aryltrifluoromethylation and chlorotrifluoromethylation
已经探索了通过调节合适的配体对未活化的环烯烃进行 Cu 催化的高化学选择性三氟甲基化反应。Cu(I)/适当的配体催化系统克服了区分涉及自由基中间体的两条途径的关键挑战,并为位点特异性螺芳基三氟甲基化和氯三氟甲基化提供了一种配体控制的方法,以提供三氟甲基化的螺四氢喹啉化合物和邻位含氯的化合物三氟甲基环烷烃。此外,与报道的氯源相比,1,2-二氯乙烷被用作三氟氯甲基化的更绿色、更经济的原料。
Direct Annulations toward Phosphorylated Oxindoles: Silver-Catalyzed Carbon-Phosphorus Functionalization of Alkenes
作者:Ya-Min Li、Meng Sun、Hong-Li Wang、Qiu-Ping Tian、Shang-Dong Yang
DOI:10.1002/anie.201209475
日期:2013.4.2
Silver screen: The AgNO3‐catalyzed carbon phosphorylation of alkenes occurs by an alkene addition/cyclization cascade. Ag+ reacts with Ph2P(O)H to form the crucial active intermediate 1, which promotes the reaction. This method requires a cheap, nontoxic silver salt as the catalyst and substrates for the transformation are simple and readily accessible.
Metal-Free Synthesis of 3,3-Disubstituted Oxoindoles by Iodine(III)-Catalyzed Bromocarbocyclizations
作者:David C. Fabry、Maciej Stodulski、Stefanie Hoerner、Tanja Gulder
DOI:10.1002/chem.201201232
日期:2012.8.27
“I” did it: An iodine(III)‐mediated bromocarbocyclization was elaborated as an efficient tool for the synthesis of oxoindoles. This method is applicable to a variety of structurally different substrates, also with chemically sensitive groups, and gives access to the heterocycles in a regio‐ and stereoselective fashion (see scheme). The indole‐2‐ones obtained can be converted easily into structurally