78258-80-7Relevant articles and documents
Versatile Cp*Co(III)(LX) Catalyst System for Selective Intramolecular C-H Amidation Reactions
Chang, Sukbok,Jung, Hoimin,Kim, Dongwook,Lee, Jeonghyo,Lee, Jia,Park, Juhyeon
, p. 12324 - 12332 (2020/08/06)
Herein, we report the development of a tailored cobalt catalyst system of Cp*Co(III)(LX) toward intramolecular C-H nitrene insertion of azidoformates to afford cyclic carbamates. The cobalt complexes were easy to prepare and bench-stable, thus offering a convenient reaction protocol. The catalytic reactivity was significantly improved by the electronic tuning of the bidentate LX ligands, and the observed regioselectivity was rationalized by the conformational analysis and DFT calculations of the transition states. The superior performance of the newly developed cobalt catalyst system could be broadly applied to both C(sp2)-H and C(sp3)-H carbamation reactions under mild conditions.
Visible-Light-Induced Intramolecular C(sp2)-H Amination and Aziridination of Azidoformates via a Triplet Nitrene Pathway
Zhang, Yipin,Dong, Xunqing,Wu, Yanan,Li, Guigen,Lu, Hongjian
, p. 4838 - 4842 (2018/08/24)
Catalytic intramolecular C-H amination and aziridination reactions of o-allylphenyl azidoformates have been achieved under visible-light irradiation, providing a mild, clean, and efficient method for the synthesis of useful benzoxazolones and [5.1.0] bicyclic aziridines. Mechanistic studies suggest that a triplet nitrene acts as the reactive intermediate. The chemoselectivity of the reaction, with alkyl olefin aziridination ? electron deficient olefin aziridination ≈ C(sp2)-H amination ? C(sp3)-H amination was observed, which may be instructive in the development of an understanding of visible-light-induced triplet nitrene transformation reactions.
Combretastatin A-4 analogues with benzoxazolone scaffold: Synthesis, structure and biological activity
Gerova, Mariana S.,Stateva, Silviya R.,Radonova, Elena M.,Kalenderska, Rositsa B.,Rusew, Rusi I.,Nikolova, Rositsa P.,Chanev, Christo D.,Shivachev, Boris L.,Apostolova, Margarita D.,Petrov, Ognyan I.
, p. 121 - 133 (2016/05/24)
In order to design and synthesize a new class of heterocyclic analogues of natural combretastatin A-4 and its synthetic derivative AVE8062, the benzoxazolone ring was selected as a scaffold for a bioisosteric replacement of the ring B of both molecules. A library of 28 cis- and trans-styrylbenzoxazolones was obtained by a modified Wittig reaction under Boden's conditions. Structures of the newly synthesized compounds bearing the 3,4,5-trimethoxy-, 3,4-dimethoxy-, 3,5-dimethoxy-, and 4-methoxystyryl fragment at position 4, 5, 6 or 7 of benzoxazolone core were determined on the basis of spectral and X ray data. The in vitro cytotoxicity of styrylbenzoxazolones against different cell lines was examined. Stilbene derivative 16Z, (Z)-3-methyl-6-(3,4,5-trimethoxystyryl)-2(3H)-benzoxazolone, showed highest antiproliferative potential of the series, with IC50 of 0.25 μM against combretastatin resistant cell line HT-29, 0.19 μM against HepG2, 0.28 μM against EA.hy926 and 0.73 μM against K562 cells. Furthermore, the results of flow cytometric analysis confirmed that 16Z induced cell cycle arrest in G2/M phase in the cell lines like combretastatin A-4. This arrest is followed by an abnormal exit of cells from mitosis without cytokinesis into a pseudo G1-like multinucleate state leading to late apoptosis and cell death. Accordingly, synthetic analogue 16Z was identified as the most promising potential anticancer agent in present study, and was selected as lead compound for further detailed investigations.
