51842-87-6Relevant articles and documents
Ruthenium-catalyzed intramolecular arene C(sp2)-H amidation for synthesis of 3,4-dihydroquinolin-2(1 H)-ones
Au, Chi-Ming,Ling, Cho-Hon,Sun, Wenlong,Yu, Wing-Yiu
supporting information, p. 3310 - 3314 (2021/05/29)
We report the [Ru(p-cymene)(l-proline)Cl] ([Ru1])-catalyzed cyclization of 1,4,2-dioxazol-5-ones to form dihydroquinoline-2-ones in excellent yields with excellent regioselectivity via a formal intramolecular arene C(sp2)-H amidation. The reactions of the 2- and 4-substituted aryl dioxazolones proceeds initially through spirolactamization via electrophilic amidation at the arene site, which is para or ortho to the substituent. A Hammett correlation study showed that the spirolactamization is likely to occur by electrophilic nitrenoid attack at the arene, which is characterized by a negative ρ value of -0.73.
Synthesis and antitumor activity of aza-brazilan derivatives containing imidazolium salt pharmacophores
Huang, Mingqin,Duan, Shengzu,Ma, Xueqiong,Cai, Bicheng,Wu, Dongmei,Li, Yan,Li, Liang,Zhang, Hongbin,Yang, Xiaodong
supporting information, p. 1027 - 1036 (2019/06/27)
The synthesis of a series of novel aza-brazilan derivatives containing imidazolium salt pharmacophores is presented. The biological activity of such imidazolium salts was further evaluated in vitro against a panel of human tumor cell lines. The results suggest that the electron-withdrawing group on the aza-brazilan moiety, substituted 5,6-dimethyl-benzimidazole ring and substitution of the imidazolyl-3-position with a 4-methylbenzyl group were essential for modulating the cytotoxic activity. Compounds 55 and 39, bearing a 4-methylbenzyl substituent at position-3 of 5,6-dimethyl-benzimidazole, were found to be the most potent compounds with IC50 values of 0.52-1.30 μM and 0.56-1.51 μM against four human tumor cell lines investigated. Particularly, compound 57 exhibited inhibitory activity against the MCF-7 cell line with an IC50 value of 0.35 μM and was 56-fold more sensitive than DDP. Moreover, compound 55 inhibited cell proliferation through inducing G0/G1 cell cycle arrest and apoptosis in SMMC-7721 cells.
Total Synthesis of Ovafolinins A and B: Unique Polycyclic Benzoxepin Lignans through a Cascade Cyclization
Davidson, Samuel J.,Barker, David
supporting information, p. 9483 - 9486 (2017/08/01)
Ovafolinins A and B, isolated from Lyonia ovalifolia var. elliptica, are lignans that contain a unique bridged structure containing a penta- and tetracyclic benzoxepin and an aryl tetralin. We report the first total synthesis of these natural products in which an acyl-Claisen rearrangement was initially utilized to construct the lignan backbone with correct relative stereochemistry. Judicious use of a bulky protecting group placed reactive moieties in the correct orientation, thereby resulting in a cascade reaction to form the bridged benzoxepin/aryl tetralin from a linear precursor in a single step. Modification of this route allowed the enantioselective synthesis of (+)-ovafolinins A and B, which confirmed the absolute stereochemistry, and comparison of optical rotation suggests that these compounds are found as scalemic mixtures in nature.