Palladium-Catalyzed, Site-Selective Direct Allylation of Aryl C–H Bonds by Silver-Mediated C–H Activation: A Synthetic and Mechanistic Investigation
作者:Sarah Yunmi Lee、John F. Hartwig
DOI:10.1021/jacs.6b10220
日期:2016.11.23
construction of a C(aryl)-C(sp3) bond by the palladium-catalyzed direct allylation of arenes with allylic pivalates in the presence of AgOPiv to afford the linear (E)-allylated arene with excellent regioselectivity; this reaction occurs with arenes that have not undergone site-selective and stereoselective direct allylation previously, such as monofluorobenzenes and non-fluorinated arenes. Mechanistic studies
The free‐radical three‐component carbocyanation of electron‐rich olefins was investigated with p‐tosyl cyanide as cyanide source. The scope and limitations of the process were established by varying the nature of the alkene and radical precursor. Carbocyanation of chiral allylsilanes was shown to occur with high diastereocontrol, leading to syn β‐silyl nitriles. The origin of the stereocontrol was
Nickel-Catalyzed Cyanation of Benzylic and Allylic Pivalate Esters
作者:Nicholas W. M. Michel、Alexandria D. M. Jeanneret、Hyehwang Kim、Sophie A. L. Rousseaux
DOI:10.1021/acs.joc.8b01763
日期:2018.10.5
substoichiometric quantities of Zn(CN)2. Alkene additives were found to inhibit catalysis, suggesting that avoiding β-hydride elimination side reactions is essential for productive catalysis. An enantioenriched allylic ester undergoes enantiospecific cross-coupling to produce an enantioenriched allylic nitrile. This method was applied to an efficient synthesis of (±)-naproxen from commerciallyavailable starting
Synthetic applications of the amine-base treatment in the ozonolysis of substituted-allyl silyl ethers or -allyl esters via a novel ene–diol type rearrangement
作者:Yung-Son Hon、Ying-Chieh Wong
DOI:10.1016/j.tetlet.2004.12.135
日期:2005.2
The ozonolysis of substituted-allyl silyl ethers or -allyl esters followed by treatment with bases gave the corresponding α-silyloxy ketones or α-acyloxy ketones in good yields. The reaction is proposed to proceed via a novel ene–diol rearrangement of the corresponding α-silyloxy aldehydes or α-acyloxy aldehydes intermediates.
作者:Zhong Liu、Zhu-Jun Shi、Lu Liu、Ming Zhang、Meng-Chen Zhang、Hao-Yang Guo、Xiao-Chen Wang
DOI:10.1021/jacs.3c03056
日期:2023.5.31
Asymmetric intermolecular C–H functionalization of pyridines at C3 is unprecedented. Herein, we report the first examples of such transformations: specifically, C3-allylation of pyridines via tandem borane and iridium catalysis. First, borane-catalyzed pyridine hydroboration generates nucleophilic dihydropyridines; then, the dihydropyridine undergoes enantioselective iridium-catalyzed allylation; and