Metal-, Photocatalyst-, and Light-Free Minisci C–H Alkylation of <i>N</i>-Heteroarenes with Oxalates
作者:Jianyang Dong、Zhen Wang、Xiaochen Wang、Hongjian Song、Yuxiu Liu、Qingmin Wang
DOI:10.1021/acs.joc.9b00972
日期:2019.6.7
for metal-, photocatalyst-, and light-freeMinisciC–Halkylation reactions of N-heteroarenes with alkyl oxalates derived from primary, secondary, and tertiary alcohols. The protocol uses environmentally benign persulfate as a stoichiometric oxidant and does not require high temperatures or large excesses of either of the substrates, making the procedure suitable for late-stage C–Halkylation of complex
Alkyl and alkoxycarbonyl radicals were generated by oxidative decarboxylation of oxalic acid monoesters by persulfate; they were then utilized for the selective substitution of quinones.
Alcohols as Latent Coupling Fragments for Metallaphotoredox Catalysis: sp<sup>3</sup>–sp<sup>2</sup> Cross-Coupling of Oxalates with Aryl Halides
作者:Xiaheng Zhang、David W. C. MacMillan
DOI:10.1021/jacs.6b09533
日期:2016.10.26
Alkyl oxalates, prepared from their corresponding alcohols, are engaged for the first time as carbon radical fragments in metallaphotoredox catalysis. In this report, we demonstrate that alcohols, native organic functional groups, can be readily activated with simple oxalyl chloride to become radical precursors in a net redox-neutral Csp3-Csp2 cross-coupling with a broad range of aryl halides. This
Visible‐light‐induced heterogeneous photocatalysis for decarboxylative alkynylation has been performed. The using of cheap, metal‐free and recyclable graphitic carbonnitride (g‐C3N4) as the photoredox catalyst in the process enables the facile transformation of a variety of carboxylic acids into structurally diverse alkyne‐containing molecular architectures under mild and environmentally‐benign conditions
可见光诱导的非均相光催化脱羧炔基反应。使用便宜,无金属且可回收的石墨氮化碳(g ‐ C 3 N 4)作为该过程中的光氧化还原催化剂,可以在温和和环境友好的条件下将多种羧酸轻松转化为结构多样的含炔分子结构。明显地,反应系统的非均质性质允许催化剂在多次运行中的回收和再利用而不损失反应性。光催化反应也可以以连续流动的方式进行并按比例放大至克级。此外,该策略在未活化烯烃的1,2氨基炔基化中的应用进一步凸显了该策略的制备能力。
C–H Alkylation of Heteroarenes with Alkyl Oxalates by Molecular Photoelectrocatalysis
作者:Hai-Chao Xu、Fan Xu、Xiao-Li Lai
DOI:10.1055/a-1296-8652
日期:2021.3
An oxidant- and metal-free photoelectrocatalytic C–H alkylation reaction of heteroarenes with alkyloxalates has been developed. Several classes of heteroaromatics, such as quinolines, isoquinolines, pyridines, and phenanthridines, can be alkylated with tertiary or secondary alkyloxalates. The photoelectrochemical synthesis employs 2,4,5,6-tetra-9H-carbazol-9-ylisophthalonitrile as a molecular catalyst