KOAc-promoted alkynylation of α-C–H bonds of ethers with alkynyl bromides under transition-metal-free conditions
作者:Jiajun Zhang、Pinhua Li、Lei Wang
DOI:10.1039/c4ob00002a
日期:——
KOAc-promoted α-position C–H activation and alkynylation of ethers with alkynyl bromides to 2-alkynyl ethers was developed under transition-metal-free conditions.
Visible‐Light‐Induced Alkynylation of α‐C–H Bonds of Ethers with Alkynyl Bromides without External Photocatalyst
作者:Xiaofei Xie、Jie Liu、Lei Wang、Min Wang
DOI:10.1002/ejoc.201900872
日期:2020.3.15
An unprecedented direct alkynylation reaction of α‐C(sp3)–H bonds of ethers under visiblelight irradiation at room temperature withoutexternalphotocatalyst was developed.
An efficient and general method for the synthesis of 2-alkynyltetrahydrofuran was developed. The regioselective functionalization of the C(sp(3))-H bond adjacent to an oxygen atom with various alkynyl bromides has been achieved under transition-metal-free reaction conditions. Sodium fluoride was found, for the first time, to promote the efficient functionalization process remarkably. Moreover, 1,2-dibromostyrenes were also found to be effective in this method forming 2-alkenyltetrahydrofurans.
Decatungstate as Direct Hydrogen Atom Transfer Photocatalyst for SOMOphilic Alkynylation
作者:Luca Capaldo、Davide Ravelli
DOI:10.1021/acs.orglett.1c00381
日期:2021.3.19
A versatile approach for the alkynylation of a variety of aliphatic hydrogen donors, including alkanes, is reported. We used tetrabutylammonium decatungstate as photocatalyst to generate organoradicals from C–H/Si–H bondsvia hydrogen atom transfer. The latter intermediates underwent SOMOphilic alkynylation by methanesulfonyl alkynes to afford internal alkynes upon loss of a sulfonyl radical. The effect