110193-59-4Relevant articles and documents
General Synthesis of Chiral α,α-Diaryl Carboxamides by Enantioselective Palladium-Catalyzed Cross-Coupling
Li, Bowen,Aliyu, Muinat A.,Gao, Zhenhua,Li, Tiejun,Dong, Wei,Li, Junchen,Shi, Enxue,Tang, Wenjun
, p. 4974 - 4978 (2020)
A general synthesis of chiral α,α-diaryl carboxamides is developed by enantioselective cross-coupling between 2-bromo-2-aryl carboxamides and arylboronic acids, leading to a series of chiral α,α-diaryl carboxamides with various electronic properties and functionalities in moderate to excellent enantioselectivities and yields. The employment of a sterically bulky chiral P,P═O ligand L2 is critical for the reactivity and selectivity. This protocol is applied to an efficient asymmetric synthesis of a key intermediate of dopamine receptor agonist SKF 38393.
Palladium-Catalyzed Asymmetric Hydroesterification of α-Aryl Acrylic Acids to Chiral Substituted Succinates
Ji, Xiaolei,Shen, Chaoren,Tian, Xinxin,Dong, Kaiwu
supporting information, p. 8645 - 8649 (2021/10/25)
A palladium-catalyzed asymmetric hydroesterification of α-aryl acrylic acids with CO and alcohol was developed, preparing a variety of chiral α-substituted succinates in moderate yields with high ee values. The kinetic profile of the reaction progress revealed that the alkene substrate first underwent the hydroesterification followed by esterification with alcohol. The origin of the enantioselectivity was elucidated by density functional theory computation.
Copper on charcoal: Cu0nanoparticle catalysed aerobic oxidation of α-diazo esters
Chu, Changhu,Dong, Wenwen,Lin, Jia,Teng, Jiangge,Wang, Zhiwei,Zhao, Rong
, p. 6120 - 6126 (2021/07/21)
By using a charcoal supported nano Cu0catalyst (Cu/C), a highly efficient oxidation of α-diazo esters to α-ketoesters with molecular oxygen as the sole oxidant has been developed. In the presence of the Cu/C catalyst, 2-aryl-α-diazo esters with both electron-donating and electron-withdrawing groups can be oxidized to the corresponding α-ketoesters efficiently. Furthermore, this Cu/C catalyst can catalyse the reaction of aryl α-diazo ester with water to form aryl ketoester, 2-aryl-2-hydroxyl acetate ester and 2-aryl acetate ester. In this case, water is split by α-diazo ester, and the diazo group is displaced by the oxygen or hydrogen atom in water. Mechanistic investigation showed that the reaction of α-diazo ester with oxygen proceeds through a radical pathway. In the presence of 2,2,6,6-tetramethyl piperidine nitrogen oxide, the reaction of α-diazo ester with oxygen is dramatically inhibited. Furthermore, the reaction of α-diazo ester with water is investigated by an isotopic tracer method, and GCMS detection showed that a disproportionation reaction occurred between α-diazo ester and water.
Copper(I)-catalyzed aerobic oxidation of α-diazoesters
Xu, Changming,Bai, Lei,Wang, Yongchang
, p. 12579 - 12584 (2020/11/09)
A practical Cu-catalyzed oxidation of α-diazoesters to α-ketoesters using molecular oxygen as an oxidant has been developed. Both electron-poor and electron-rich aryl α-diazoesters are suitable substrates and provide the α-ketoesters in good yields. In this oxidative system, α-diazo-β-ketoesters are also compatible as substrates but unexpectedly furnish α-ketoesters via C-C bond cleavage, rather than the vicinal tricarbonyl products.
Controllable chemoselectivity in the coupling of bromoalkynes with alcohols under visible-light irradiation without additives: Synthesis of propargyl alcohols and α-ketoesters
Ni, Ke,Meng, Ling-Guo,Ruan, Hongjie,Wang, Lei
supporting information, p. 8438 - 8441 (2019/07/22)
The chemoselectivity of visible-light-induced coupling reactions of bromoalkynes with alcohols can be controlled by simple changes to the reaction atmosphere (N2 or O2). A N2 atmosphere favours propargyl alcohols via a direct C-C coupling process, whereas an O2 atmosphere results in the generation of α-ketoesters through the oxidative CC/C-O coupling pathway.
Switchable C-H Functionalization of N-Tosyl Acrylamides with Acryloylsilanes
Song, Shengjin,Lu, Ping,Liu, Huan,Cai, Sai-Hu,Feng, Chao,Loh, Teck-Peng
supporting information, p. 2869 - 2872 (2017/06/13)
A controllable Rh-catalyzed protocol to access alkylation and alkenylation-annulation of N-tosyl acrylamide with acryloyl silane is reported. In contrast to the directing group or catalyst-dependent divergent sp2 C-H alkylation/alkenylation, the intrinsic property of acryloylsilane allows the switchable reaction manifold, thereby affording either alkylation or annulation products with slight modification of the reaction conditions.
Asymmetric Hydrogenation of α-Substituted Acrylic Acids Catalyzed by a Ruthenocenyl Phosphino-oxazoline-Ruthenium Complex
Li, Jing,Shen, Jiefeng,Xia, Chao,Wang, Yanzhao,Liu, Delong,Zhang, Wanbin
supporting information, p. 2122 - 2125 (2016/06/01)
Asymmetric hydrogenation of various α-substituted acrylic acids was carried out using RuPHOX-Ru as a chiral catalyst under 5 bar H2, affording the corresponding chiral α-substituted propanic acids in up to 99% yield and 99.9% ee. The reaction could be performed on a gram-scale with a relatively low catalyst loading (up to 5000 S/C), and the resulting product (97%, 99.3% ee) can be used as a key intermediate to construct bioactive chiral molecules. The asymmetric protocol was successfully applied to an asymmetric synthesis of dihydroartemisinic acid, a key intermediate required for the industrial synthesis of the antimalarial drug artemisinin.
6-Beta-(alpha-etherified oxymino)-acyl amino penicillins
-
, (2008/06/13)
Compounds of formula (I): wherein R1 is optionally substituted phenyl and R is a cycloalkyl group having an alkyl substituent in the 1-position; or R1 is phenyl substituted by at least one fluorine atom and/or at least one trifluoromethyl group and R is hydrogen or an organic radical, and their salts and esters, are useful in the treatment of bacterial infections in humans and animals.
