Cyclopropanation of Terminal Alkenes through Sequential Atom‐Transfer Radical Addition/1,3‐Elimination
作者:Nicholas D. C. Tappin、Weronika Michalska、Simon Rohrbach、Philippe Renaud
DOI:10.1002/anie.201907962
日期:2019.10
An operationally simple method to affect an atom-transfer radical addition of commercially available ICH2 Bpin to terminal alkenes has been developed. The intermediate iodide can be transformed in a one-pot process into the corresponding cyclopropane upon treatment with a fluoride source. This method is highly selective for the cyclopropanation of unactivated terminal alkenes over non-terminal alkenes
Mild Ring‐Opening 1,3‐Hydroborations of Non‐Activated Cyclopropanes
作者:Di Wang、Xiao‐Song Xue、Kendall N. Houk、Zhuangzhi Shi
DOI:10.1002/anie.201811036
日期:2018.12.17
The Brown hydroboration reaction, first reported in 1957, is the addition of B−H across an olefin in an anti‐Markovnikov fashion. Here, we solved a long‐standing problem on mild 1,3‐hydroborations of non‐activated cyclopropanes. A three‐component system including cyclopropanes, boron halides, and hydrosilanes has been developed for borylative ring‐opening of cyclopropanes following the anti‐Markovnikov
A Palladium-Catalyzed Methylenation of Olefins Using Halomethylboronate Reagents
作者:Tim den Hartog、Juan Manuel Sarria Toro、Peter Chen
DOI:10.1021/ol403695b
日期:2014.2.21
Methylenation of electron-rich olefins is a highly challenging reaction, for which we have developed a new methodology exploiting Pd-catalysis and halomethylboronate reagents, the latter replacing diazomethane and zinc carbenoids as methylene donors. Optimization of the reaction for norbornene and extension to several other olefins are reported, with reasonable-to-excellent yields of cyclopropanes
Switchable Direct Oxygenative Arylation of C(sp<sup>3</sup>)–H Bonds via Electrophotocatalysis
作者:Yan Zhang、Xiang Sun、Ji-Hu Su、Tong Li、Chengbin Du、Kuiliang Li、Qi Sun、Zhenggen Zha、Zhiyong Wang
DOI:10.1021/acs.orglett.3c01751
日期:2023.7.14
A metal-free electrophotochemical C(sp3)-H arylation was developed under mild conditions. This method enables a switchable synthesis of diaryl alcohols and diaryl alkanes from inactive benzylic carbons. More importantly, a cheap and safe mediator N-chlorosuccinimide (NCS) was developed, which was employed for the hydrogen atom transfer (HAT) process of the benzylic C–H bond. In addition, this active