Iron‐Catalyzed Tertiary Alkylation of Terminal Alkynes with 1,3‐Diesters via a Functionalized Alkyl Radical
作者:Ming‐Qing Tian、Zhen‐Yao Shen、Xuefei Zhao、Patrick J. Walsh、Xu‐Hong Hu
DOI:10.1002/anie.202100641
日期:2021.4.19
Direct oxidative C(sp)−H/C(sp3)−H cross‐coupling offers an ideal and environmentally benign protocol for C(sp)−C(sp3) bond formations. As such, reactivity and site‐selectivity with respect to C(sp3)−H bond cleavage have remained a persistent challenge. Herein is reported a simple method for iron‐catalyzed/silver‐mediated tertiary alkylation of terminal alkynes with readily available and versatile 1
Multiple-functionalizations of terminal alkynes with sodium sulfinates and<i>tert</i>-butyl nitrite: facile synthesis of 2<i>H</i>-azirines
作者:Xingyi He、Xin Yue、Lei Zhang、Shuang Wu、Ming Hu、Jin-Heng Li
DOI:10.1039/c9cc00625g
日期:——
A new, catalyst-free tandem annulation route to 2,2-disulfonyl-2H-azirines via multiple-functionalizations of terminal alkynes with sodium sulfinates and tert-butyl nitrite is described. The use of sodium sulfinates and tert-butyl nitrite enables the formation of sulfonyl and NO radicals to selectively initiate and terminate the tandem annulation protocol, constituting a straightforward, conceptually
Copper-Catalyzed Radical Bis(trifluoromethylation) of Alkynes and 1,3-Enynes
作者:Haigen Shen、Hawen Xiao、Lin Zhu、Chaozhong Li
DOI:10.1055/s-0039-1690187
日期:2020.1
The copper-catalyzed radical bis(trifluoromethylation) of alkynes and 1,3-enynes is described. With Cu(CH3CN)4BF4 as the catalyst, the reaction of arylalkynes with Togni reagent II and (bpy)Zn(CF3)2at roomtemperature affords the corresponding 1,2-bis(trifluoromethylated) alkenes in good yields with excellent E-stereoselectivity. Under similar conditions, the reaction of 1,3-enynes provides the corresponding
Et3N-catalyzed direct cycloaddition reaction of allenoates with acceptor diazo compounds
作者:Yu-Ting Tian、Fa-Guang Zhang、Jun-An Ma
DOI:10.1016/j.tet.2021.131922
日期:2021.2
A Et3N-catalyzed [3 + 2] cycloadditionreaction of allenoates with acceptor diazo compounds that include diazoesters, diazoketones, and diazoamides, has been developed. This transformation allows direct and regioselective synthetic route to a variety of pyrazoles from allenoates. 3-Alkynoates also participate in the cycloadditionreaction by isomerizing to the corresponding allenoates in situ.
Rh(I)‐Catalyzed Decarboxylative Arylation of Alkynyl Cyclic Carbonates: Divergent Access to Substituted
<i>α</i>
‐Allenols and 1,3‐Butadienes
作者:Geetanjali S. Sontakke、Rahul K. Shukla、Chandra M. R. Volla
DOI:10.1002/adsc.202101064
日期:2022.2
Rh(I)-catalyzed decarboxylative arylation of alkynyl cyclic carbonates using commercially available and low-toxic aryl boronic acids has been disclosed. Depending on the nature of the cyclic carbonates, the methodology provides a straightforward platform to access either substituted 2,3-allenols or 1,3-butadiene derivatives. Internal alkynyl cyclic carbonates undergo monoarylation to conveniently afford