19277-55-5Relevant academic research and scientific papers
Nickel-Catalyzed Cross-Coupling of Aryl 2-Pyridyl Ethers with Organozinc Reagents: Removal of the Directing Group via Cleavage of the Carbon-Oxygen Bonds
Dai, Wei-Can,Yang, Bo,Xu, Shi-He,Wang, Zhong-Xia
, p. 2235 - 2243 (2021/02/01)
Reaction of aryl 2-pyridyl ethers with arylzinc reagents under catalysis of NiCl2(PCy3)2 affords aryl-aryl cross-coupling products via selective cleavage of CAr-OPy bonds. The reaction features a wide substrate range and good compatibility of functional groups. β-H-free alkylzinc reagents are also applicable as the nucleophiles in the transformation, whereas β-H-containing alkylzinc reagents lead to a mixture of cross-coupling and hydrogenation products.
Construction of Esters through Sulfuryl Fluoride (SO 2 F 2) Mediated Dehydrative Coupling of Carboxylic Acids with Alcohols at Room Temperature
Qin, Hua-Li,S Alharbi, Njud,Wang, Shi-Meng
, p. 3901 - 3907 (2019/10/11)
A facile method for the construction of esters through dehydrative coupling of carboxylic acids with alcohols is developed. The reactions are mediated by sulfuryl fluoride (SO 2 F 2) at room temperature and proceed with high efficiency. The method has several advantages including broad substrate scope, mild conditions, excellent functional group compatibility and affords high yields, even on gram scale.
Efficient and Recyclable RuCl3 ? 3H2O Catalyst Modified with Ionic Diphosphine for the Alkoxycarbonylation of Aryl Halides
Zhou, Qing,Liu, Lei,Guo, Wen-Di,Liang, Wen-Yu,Lu, Yong,Liu, Ye
, p. 166 - 172 (2019/02/01)
A series of ionic (mono-/di-)phosphines (L2, L4, and L6) with structural similarity and their corresponding neutral counterparts (L1, L3, and L5) were applied to modulate the catalytic performance of RuCl3 ? 3H2O. With the involvement of the ionic diphosphine (L4), in which the two phosphino-fragments were linked by butylene group, RuCl3 ? 3H2O with advantages of low cost, robustness, and good availability was found to be an efficient and recyclable catalyst for the alkoxycarbonylation of aryl halides. The L4-based RuCl3 ? 3H2O system corresponded to the best conversion of PhI (96 %) along with 99 % selectivity to the target product of methyl benzoate as well as the good generality to alkoxycarbonylation of different aryl halides (ArX, X=I and Br) with alcohols MeOH, EtOH, i-PrOH and n-BuOH. The electronic and steric effects of the applied phosphines, which were analyzed by the 31P NMR for 1J31P-77Se1J measurement and single-crystal X-ray diffraction, were carefully co-related to the performance RuCl3 ? 3H2O catalyst. In addition, the L4-based RuCl3 ? 3H2O system could be recycled successfully for at least eight runs in the ionic liquid [Bmim]PF6.
PRODRUGS OF HYDROXAMATE-BASED GCPII INHIBITORS
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Page/Page column 49; 86, (2018/06/06)
Prodrugs of hydroxamate-based GCPII inhibitors and methods of their use for treating a disease or condition are disclosed.
SO2F2-Mediated One-Pot Synthesis of Aryl Carboxylic Acids and Esters from Phenols through a Pd-Catalyzed Insertion of Carbon Monoxide
Fang, Wan-Yin,Leng, Jing,Qin, Hua-Li
, p. 2323 - 2331 (2017/09/06)
A one-pot Pd-catalyzed carbonylation of phenols into their corresponding aryl carboxylic acids and esters through the insertion of carbon monoxide has been developed. This procedure offers a direct synthesis of aryl carboxylic acids and esters from inexpensive and abundant starting materials (phenols, SO2F2 and CO) under mild conditions. This method tolerates a broad range of functional groups and is also applicable for the modification of complicated natural products.
Metal-free radical aromatic carbonylations mediated by weak bases
Koziakov, Denis,Jacobi Von Wangelin, Axel
supporting information, p. 6715 - 6719 (2017/08/22)
We report a new method of metal-free alkoxycarbonylation. This reaction involves the generation of aryl radicals from arenediazonium salts by a very weak base (HCO2Na) under mild conditions. Subsequent radical trapping with carbon monoxide and alcohols gives alkyl benzoates. The conditions (metal-free, 1 equiv. base, MeCN, r.t., 3 h) tolerate various functional groups (I, Br, Cl, CF3, SF5, NO2, ester). Mechanistic studies indicate the operation of a radical aromatic substitution mechanism.
Visible-light induced oxidative Csp3-H activation of methyl aromatics to methyl esters
Zhang, Lingling,Yi, Hong,Wang, Jue,Lei, Aiwen
supporting information, p. 5122 - 5126 (2016/10/05)
Direct functionalization of readily available hydrocarbons under mild conditions fulfills the requirements of green and sustainable chemistry. In this work, a mild and green catalytic oxidative Csp3-H activation of methyl aromatics using O2via photocatalysis has been achieved. A lot of methyl aromatics can be tolerated, providing a green route for aromatic methyl carboxylates. In addition, this protocol can be performed on a gram scale.
Metal-free carbonylations by photoredox catalysis
Majek, Michal,Von Wangelin, Axel Jacobi
supporting information, p. 2270 - 2274 (2015/02/19)
The synthesis of benzoates from aryl electrophiles and carbon monoxide is a prime example of a transition-metalcatalyzed carbonylation reaction which is widely applied in research and industrial processes. Such reactions proceed in the presence of Pd or Ni catalysts, suitable ligands, and stoichiometric bases. We have developed an alternative procedure that is free of any metal, ligand, and base. The method involves a redox reaction driven by visible light and catalyzed by eosin Y which affords alkyl benzoates from arene diazonium salts, carbon monoxide, and alcohols under mild conditions. Tertiary esters can also be prepared in high yields. DFT calculations and radical trapping experiments support a catalytic photoredox pathway without the requirement for sacrificial redox partners.
Transition-metal-free transformation of aryl bromides into aromatic esters and amides via aryl trichloromethyl ketones
Dohi, Souya,Moriyama, Katsuhiko,Togo, Hideo
, p. 7815 - 7822 (2013/12/04)
A variety of aryl bromides have been treated with Mg and then chloral, followed by tBuOCl and subsequently alcohols or amines to produce the corresponding aromatic esters or amides in good yields via the formation of aryl trichloromethyl ketones as intermediates. These reactions are examples of a transition-metal-free one-pot preparation of aromatic esters and amides from aryl bromides. Aryl bromides have been treated with Mg and then chloral, followed by tBuOCl or tBuOCl with I2 as an additive, and subsequently alcohols or amines to form the corresponding aromatic esters and aromatic amides via aryl trichloromethyl ketones as intermediates. Copyright
Pd-catalyzed aldehyde to ester conversion: A hydrogen transfer approach
Tschaen, Brittany A.,Schmink, Jason R.,Molander, Gary A.
supporting information, p. 500 - 503 (2013/04/11)
Aliphatic and aromatic aldehydes are successfully converted into their corresponding esters using Pd(OAc)2 and XPhos. This approach utilizes a hydrogen transfer protocol: concomitant reduction of acetone to isopropanol provides an inexpensive and sustainable approach that mitigates the need for other oxidants.
