226931-47-1Relevant 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.
Enantioselective decarboxylative Mannich reaction of β-keto acids withC-alkynylN-BocN,O-acetals: access to chiral β-keto propargylamines
Chen, Li-Jun,Li, Wei,Shen, Bao-Chun,Sun, Zhong-Wen,Xie, Hui-Ding,Zhang, Cong-Cong
supporting information, p. 8607 - 8612 (2021/10/20)
The chiral keto-substituted propargylamines are an essential class of multifunctional compounds in the field of organic and pharmaceutical synthesis and have attracted considerable attention, but the related synthetic approaches remain limited. Therefore, a concise and efficient method for the enantioselective synthesis of β-keto propargylaminesviachiral phosphoric acid-catalyzed asymmetric Mannich reaction between β-keto acids andC-alkynylN-BocN,O-acetals as easily availableC-alkynyl imine precursors has been demonstrated here, affording a broad scope of β-ketoN-Boc-propargylamines in high yields (up to 97%) with generally high enantioselectivities (up to 97?:?3 er).
Nickel-catalyzed enantioselective hydrogenation of β-(acylamino)acrylates: Synthesis of chiral β-amino acid derivatives
Li, Xiuxiu,You, Cai,Li, Shuailong,Lv, Hui,Zhang, Xumu
supporting information, p. 5130 - 5133 (2017/11/06)
The nickel-catalyzed asymmetric hydrogenation of β-(acylamino)acrylates has been developed, affording chiral β-amino acid derivatives with excellent yields (95-99% yield) and enantioselectivities (97-99% ee). With the Ni-Binapine system, high enantioselectivities (98-99% ee) have also been obtained in the hydrogenation of Z/E isomeric mixtures of β-alkyl and β-aryl β-(acylamino)acrylates. The synthesis of chiral β-amino acid derivatives on a gram scale has also been achieved with 0.2 mol % catalyst loading.
