20129-10-6Relevant academic research and scientific papers
Oxidative Photochlorination of Electron-Rich Arenes via in situ Bromination
Düsel, Simon Josef Siegfried,K?nig, Burkhard
supporting information, p. 1491 - 1495 (2019/04/30)
Electron-rich arenes are oxidatively photochlorinated in the presence of catalytic amounts of bromide ions, visible light, and 4CzIPN as organic photoredox catalyst. The substrates are brominated in situ in a first photoredox-catalyzed oxidation step, followed by a photocatalyzed ipso-chlorination, yielding the target compounds in high ortho/para regioselectivity. Dioxygen serves as a green and convenient terminal oxidant. The use of aqueous hydrochloric acid as the chloride source reduces the amount of saline by-products.
Sulfoxide-Promoted Chlorination of Indoles and Electron-Rich Arenes with Chlorine as Nucleophile
Ji, Yuan-Zhao,Li, Hui-Jing,Wang, Yi-Ruo,Wu, Yan-Chao,Zhang, Zheng-Yan
supporting information, (2020/02/05)
An efficient chlorination of indoles and electron-rich arenes with chlorine anion as nucleophile is described. With the use of ethyl phenyl sulfoxide as the promoter, the reaction went smoothly under metal-free and mild conditions. Various indoles and electron-rich arenes are converted into the corresponding chlorinated compounds in moderate to excellent yields. A plausible interrupted Pummerer reaction mechanism was proposed without the oxidation of chloride anion. In addition, the byproduct thioether could be easily converted to the starting material sulfoxide just by a simple oxidation reaction. (Figure presented.).
Decarboxylative Halogenation and Cyanation of Electron-Deficient Aryl Carboxylic Acids via Cu Mediator as Well as Electron-Rich Ones through Pd Catalyst under Aerobic Conditions
Fu, Zhengjiang,Li, Zhaojie,Song, Yuanyuan,Yang, Ruchun,Liu, Yanzhu,Cai, Hu
, p. 2794 - 2803 (2016/04/26)
Simple strategies for decarboxylative functionalizations of electron-deficient benzoic acids via using Cu(I) as promoter and electron-rich ones by employing Pd(II) as catalyst under aerobic conditions have been established, which lead to smooth synthesis of aryl halides (-I, Br, and Cl) through the decarboxylative functionalization of benzoic acids with readily available halogen sources CuX (X = I, Br, Cl), and easy preparation of benzonitriles from decarboxylative cyanation of aryl carboxylic acids with nontoxic and low-cost K4Fe(CN)6 under an oxygen atmosphere for the first time.
Pd(II)-catalyzed bromo- and chlorodecarboxylation of electron-rich arenecarboxylic acids
Peng, Xuefeng,Shao, Xiang-Feng,Liu, Zhong-Quan
supporting information, p. 3079 - 3081 (2013/07/11)
A bromo- and chlorodecarboxylation of various aromatic carboxylic acids catalyzed by Pd(II) has been developed in this work. A series of electron-rich arenecarboxylic acids gave the corresponding decarboxylative monohalogenation products under the typical reaction conditions.
Oxygenation and chlorination of aromatic hydrocarbons with hydrochloric acid photosensitized by 9-mesityl-10-methylacridinium under visible light irradiation
Ohkubo, Kei,Mizushima, Kentaro,Fukuzumi, Shunichi
, p. 205 - 220 (2013/03/13)
Efficient photocatalytic oxygenation of toluene occurs under visible light irradiation of 9-mesityl-10-methylacridinium (Acr+-Mes) in oxygen-saturated acetonitrile containing toluene and aqueous hydrochloric acid with a xenon lamp for 15 h. The oxygenated products, benzoic acid (70 %) and benzaldehyde (30 %), were formed after the photoirradiation. The photocatalytic reaction is initiated by intramolecular photoinduced electron transfer from the mesitylene moiety to the singlet excited state of the Acr+ moiety of Acr+-Mes, which affords the electron-transfer state, Acr ?-Mes?+. The Mes?+ moiety can oxidize chloride ion (Cl-) by electron transfer to produce chlorine radical (Cl?), whereas the Acr? moiety can reduce O2 to O 2 ?-. The Cl ? radical produced abstracts a hydrogen from toluene to afford benzyl radical in competition with the bimolecular radical coupling of Cl ?. The benzyl radical reacts with O2 rapidly to afford the peroxyl radical, leading to the oxygenated product, benzaldehyde. Benzaldehyde is readily further photooxygenated to yield benzoic acid with Acr?-Mes?+. In the case of an aromatic compound with electron-donating substituents, 1,3,5-trimethoxybenzene, photocatalytic chlorination occurred efficiently under the same photoirradiation conditions to yield a monochloro-substituted compound, 2,4,6-trimethoxychlorobenzene.
Asymmetric synthesis of α-aryl amino acids; Aryne-mediated diastereoselective arylation
Jones, Elizabeth P.,Jones, Peter,Barrett, Anthony G. M.
supporting information; experimental part, p. 1012 - 1015 (2011/05/15)
An aryne-mediated α-arylation reaction of Schoellkopf's bis-lactim ether is described. Arynes were generated via an ortho-lithiation approach, affording syn-arylated products in up to 94:6 dr with moderate to good yields and excellent regioselectivities. Hydrolysis provided a variety of substituted arylglycines containing a range of functional groups without racemization.(Figure Presented)
