报道了烯烃和炔烃的光催化硼氢化反应。使用新设计的铜光催化剂和 B 2 Pin 2可以形成硼基自由基,该自由基可用于大量烯烃和炔烃的硼氢化反应。硼氢化产物以高产率分离,在温和条件下具有优异的非对映选择性和高官能团耐受性。硼氢化反应是在连续流动条件下开发的,以证明其合成效用。研究了反应机理,并提出了原位形成的硼酸盐和处于激发态的铜光催化剂之间的氧化反应,以形成硼基自由基。
Alkylboronic Esters from Copper-Catalyzed Borylation of Primary and Secondary Alkyl Halides and Pseudohalides
作者:Chu-Ting Yang、Zhen-Qi Zhang、Hazmi Tajuddin、Chen-Cheng Wu、Jun Liang、Jing-Hui Liu、Yao Fu、Maria Czyzewska、Patrick G. Steel、Todd B. Marder、Lei Liu
DOI:10.1002/anie.201106299
日期:2012.1.9
unprecedented copper‐catalyzed cross‐coupling reaction of the title compounds with diboron reagents is described (see scheme; Ts=4‐toluenesulfonyl). This reaction can be used to prepare both primary and secondaryalkylboronic esters having diverse structures and functional groups. The resulting products would be difficult to access by other means.
A copper(II)-catalyzed borylation of alkyl halides with bis(pinacolato)diboron (B2pin2) has been developed, which can be carried out in air, providing a wide range of primary, secondary, and some tertiary alkylboronates in high yields. A variety of functional groups are tolerated and the protocol is also applicable to unactivated alkyl chlorides (including 1,1- and 1,2-dichlorides). Preliminary mechanistic
Transition-Metal-Free Borylation of Alkyl Iodides via a Radical Mechanism
作者:Qianyi Liu、Junting Hong、Beiqi Sun、Guangcan Bai、Feng Li、Guoquan Liu、Yang Yang、Fanyang Mo
DOI:10.1021/acs.orglett.9b01951
日期:2019.9.6
transition-metal-free borylation of alkyliodides. This method uses commercially available diboron reagents as the boron source and exhibits excellent functional group compatibility. Furthermore, a diverse range of primary and secondaryalkyliodides could be effectively transformed to the corresponding alkylboronates in excellent yield. Mechanisticinvestigations suggest that this borylation reaction
Direct Difluoromethylation of Alcohols with an Electrophilic Difluoromethylated Sulfonium Ylide
作者:Jiansheng Zhu、Yafei Liu、Qilong Shen
DOI:10.1002/anie.201603166
日期:2016.7.25
mild reaction conditions and with good functional‐group tolerance was developed. The development of the method was based on the invention of a stable, electrophilic, difluoromethylating reagent, difluoromethyl‐(4‐nitrophenyl)‐bis(carbomethoxy) methylide sulfonium ylide, which was synthesized by reaction of the easily available 4‐nitrophenyl (difluoromethyl)thioether and dimethyl diazomalonate in the