C–H Alkylation via Multisite-Proton-Coupled Electron Transfer of an Aliphatic C–H Bond
作者:Carla M. Morton、Qilei Zhu、Hunter Ripberger、Ludovic Troian-Gautier、Zi S. D. Toa、Robert R. Knowles、Erik J. Alexanian
DOI:10.1021/jacs.9b06834
日期:2019.8.21
The direct, site-selective alkylation of unactivated C(sp3)-H bonds in organic substrates is a long-standing goal in synthetic chemistry. General approaches to the activation of strong C-H bonds include radical-mediated processes involving highly reactive intermediates, such as heteroatom-centered radicals. Herein, we describe a catalytic, intermolecular C-H alkylation that circumvents such reactive
Intermolecular Anti-Markovnikov Hydroamination of Unactivated Alkenes with Sulfonamides Enabled by Proton-Coupled Electron Transfer
作者:Qilei Zhu、David E. Graff、Robert R. Knowles
DOI:10.1021/jacs.7b11144
日期:2018.1.17
Here we report a catalytic method for the intermolecularanti-Markovnikovhydroamination of unactivated alkenes using primary and secondary sulfonamides. These reactions occur at room temperature under visible light irradiation and are jointly catalyzed by an iridium(III) photocatalyst, a dialkyl phosphate base, and a thiol hydrogen atom donor. Reaction outcomes are consistent with the intermediacy
在这里,我们报告了一种使用初级和次级磺酰胺对未活化烯烃进行分子间抗马尔科夫尼科夫加氢胺化的催化方法。这些反应在室温下在可见光照射下发生,并由铱 (III) 光催化剂、磷酸二烷基酯碱和硫醇氢原子供体共同催化。反应结果与通过磺酰胺 NH 键的质子耦合电子转移激活产生的 N 中心磺酰胺自由基的中间体一致。概述了反应的合成范围(> 60 个例子)和机械特征的研究。
作者:Shuai Zheng、Shuo-Qing Zhang、Borna Saeednia、Jiawang Zhou、Jessica M. Anna、Xin Hong、Gary A. Molander
DOI:10.1039/d0sc01459a
日期:——
The selective 1,2-aminoacylation of olefins provides opportunities for the rapid construction of nitrogen-containing molecules. However, the lack of CO-free acylation reactions has limited their application. By using photoredox proton-coupled electron transfer (PCET)/Ni dual-catalysis, a highly regio- and diastereoselective amidoacylation of unactivated olefins has been developed. Various acyl electrophiles
Chain Entropy Beats Hydrogen Bonds to Unfold and Thread Dialcohol Phosphates inside Cyanostar Macrocycles To Form [3]Pseudorotaxanes
作者:Rachel E. Fadler、Abdelaziz Al Ouahabi、Bo Qiao、Veronica Carta、Niklas F. König、Xinfeng Gao、Wei Zhao、Yankai Zhang、Jean-François Lutz、Amar H. Flood
DOI:10.1021/acs.joc.0c02887
日期:2021.3.19
including DNA binding, enantioselective catalysis, and recently template-directed rotaxane synthesis. Beyond ATP and a few commercial substrates, however, little is known about how substituentseffect organophosphate recognition. Here, we examined alcohol substituents and their impact on recognition by cyanostar macrocycles. The organophosphates were disubstituted by alcohols of various chain lengths, dipropanol
取代磷酸盐的识别支撑着许多过程,包括 DNA 结合、对映选择性催化和最近的模板引导的轮烷合成。然而,除了 ATP 和一些商业底物之外,人们对取代基如何影响有机磷酸酯识别知之甚少。在这里,我们研究了醇取代基及其对氰星大环化合物识别的影响。有机磷酸酯被不同链长的醇、二丙醇、二己醇和磷酸二癸醇二取代,每种都使用模块化固相合成获得。基于已知的氰星π堆积二聚体对磷酸盐的尺寸选择性结合,预计会出现线状[3]拟轮烷。虽然有丁基取代基,但拟轮烷的形成受到末端羟基和阴离子磷酸盐单元之间竞争性 OH·O –氢键的破坏。晶体学还表明形成了反向折叠的丙醇构象,从而形成了八元环和栖息的氰星组装体。受伴随环形成而建立的熵罚的启发,我们通过将取代基的大小扩展到己醇和癸醇来恢复[3]拟轮烷。链熵克服了热函有利的 OH·O –接触,有利于氰星内部二己醇和二癸醇磷酸盐无缝、高保真螺纹所需的随机螺旋构象。这些研究强调了磷酸盐取
Efficient, Diastereoselective Chemical Synthesis of a β-Mannopyranosyl Phosphoisoprenoid
作者:David Crich、Vadim Dudkin
DOI:10.1021/ol006725p
日期:2000.11.1
[reaction: see text] Tetrabutylammonium benzyl dihydrophytylphosphate was coupled to S-phenyl 2,3-di-O-benyl-4, 6-O-benzylidene-1-thio-alpha-D-mannopyranoside S-oxide on activation with triflic anhydride in toluene at -78 degrees C to give the corresponding beta-mannosyl phosphate in 56% yield with no detectable formation of the alpha-anomer. Treatment with sodium in liquid ammonia then afforded the