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
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
Photoredox-Catalyzed Allylic Defluorinative Alkoxycarbonylation of Trifluoromethyl Alkenes through Intermolecular Alkoxycarbonyl Radical Addition
作者:Jia-Xin Wang、Wei Ge、Ming-Chen Fu、Yao Fu
DOI:10.1021/acs.orglett.1c04359
日期:2022.2.25
medicinal chemistry, but efficient synthesis of β-gem-difluoroalkene esters remains challenging so far. Herein, we disclose a photoredox-catalyzed allylic defluorinative alkoxycarbonylation of trifluoromethyl alkenes enabled by intermolecular alkoxycarbonyl radical addition. A wide variety of alcohol oxalate derivatives were amenable, affording various β-gem-difluoroalkene esters with excellent functional
photocatalytic reaction of N-alkyl-N-methacryloylbenzamides with monoalkyl oxalates is described. Monoalkyl oxalates undergo single-electron oxidation/CO2 extrusion to generate alkoxycarbonyl radicals, followed by the addition and subsequent cyclization to give alkoxycarbonyl substituted isoquinolinediones. A wide variety of monoalkyl oxalates were amenable in this protocol, affording various alkoxycarbonyl
A metal-, light-free radical alkylation reaction of purines and nucleosides has been achieved with readily available alcohols (1°, 2°, 3°) as the alkyl radical sources enabled by oxalates, which does not need any catalysts, N2 protection, and protecting groups. Although there are three potential active C(sp2)H bonds and four interferential nitrogen atoms in the purine motif, the reaction still shows
以草酸盐为烷基自由基源,以易得的醇(1°、2°、3°)实现了嘌呤和核苷的金属、光自由基烷基化反应,不需要任何催化剂、N 2保护和保护基团。尽管嘌呤基序中存在3个潜在的活性C( sp 2 ) H键和4个干扰氮原子,但该反应在C 6 H位上仍然表现出优异的区域选择性,并且不存在多烷基化问题。此外,该方法表现出广泛的功能组耐受性,并且可扩展至克级,可应用于后期 C 嘌呤的 H 烷基化合成具有抗 CEM 活性的 6-环戊基星云碱,从而证明了其实用性。