134568-16-4Relevant articles and documents
Cu-Catalyzed Synthesis of Benzoxazole with Phenol and Cyclic Oxime
Wang, Zheng-Hai,Wang, Dong-Hui
supporting information, p. 782 - 785 (2022/01/20)
A Cu-catalyzed straightforward synthesis of benzoxazoles from free phenols and cyclic oxime esters is reported. The mild reaction conditions tolerate various electron-withdrawing and electron-donating functional groups on both substrates, affording benzoxazoles in moderate to good yields. With this protocol, large-scale syntheses of Ezutromid and Flunoxaprofe in one or two steps are demonstrated. A catalytic mechanism, which includes Cu-catalyzed amination via inner-sphere electron transfer and consequent annulation, is proposed.
Access to pyridines via cascade nucleophilic addition reaction of 1,2,3-triazines with activated ketones or acetonitriles
Zhang, Yuan,Luo, Han,Lu, Qixing,An, Qiaoyu,Li, You,Li, Shanshan,Tang, Zongyuan,Li, Baosheng
supporting information, p. 393 - 396 (2020/05/18)
We studied the cascade nucleophilic addition reactions of 1,2,3-triazines with activated acetonitriles or ketones, which were used to construct highly substituted pyridines that are not easily accessed by conventional methods. The strategy addressed some structural diversity issues currently facing medicinal chemistry, and the resulting pyridines could be used as convenient precursors for the synthesis of related pharmaceuticals. In particular, our method was applied to the syntheses of the marketed drug etoricoxib and several biologically important molecules in a few steps.
Chiral Vanadyl(V) Complexes Enable Efficient Asymmetric Reduction of β-Ketoamides: Application toward (S)-Duloxetine
Chen, Chien-Tien,Maity, Nabin Ch.,Agarwal, Rachit,Lai, Chien-Fu,Liao, Yiya,Yu, Wei-Ru
supporting information, p. 6408 - 6419 (2020/07/14)
High-valent chiral oxidovanadium(V) complexes derived from 3,5-substituted-N-salicylidene-l-tert-leucine were used as catalysts in asymmetric reduction of N-benzyl-β-ketoamides. Among six different solvents, three different alcohol additives, and two different boranes examined, the use of pinacolborane in tetrahydrofuran (THF) with a t-BuOH additive led to the best results at -20 °C. The corresponding β-hydroxyamides can be furnished with yields up to 92percent and an enantiomeric excess (ee) up to 99percent. We have successfully extended this catalytic protocol for the synthesis of an (S)-duloxetine precursor.
