22971-32-0Relevant articles and documents
Synthesis, structure-activity relationships, and antitumor studies of 2-benzoxazolyl hydrazones derived from alpha-(N)-acyl heteroaromatics
Easmon, Johnny,Pürstinger, Gerhard,Thies, Katrin-Sofia,Heinisch, Gottfried,Hofmann, Johann
, p. 6343 - 6350 (2006)
Recently we have described the antitumor activities of 2- benzoxazolylhydrazones derived from 2-formyl and 2-acetylpyridines. In search of a more efficacious analogue, compounds in which the 2-acetylpyridine moiety has been replaced by 2-acylpyridine and α-(N)-acetyldiazine/quinoline groups have been synthesized. The 2-acylpyridyl hydrazones inhibited in vitro cell proliferation in the nM range, whereas the hydrazones derived from the α-(N)-acetyldiazines/quinolines inhibited cell growth in the μM range. Compounds tested in the NCI-60 cell assay were effective inhibitors of leukemia, colon, and ovarian cancer cells. E-13k [N-benzoxazol-2-yl-N′-(1- isoquinolin-3-yl-ethylidene)-hydrazine] inhibited the proliferation of MCF-7 breast carcinoma cells more efficiently than nontransformed MCF-10A cells. It is not transported by P-glycoprotein and a weak MRP substrate. Increased concentrations of serum or α1-acid glycoprotein did not reduce the antiproliferative activity of the compound. In the in vivo hollow fiber assay, E-13k achieved a score of 24, with a net cell kill of OVCAR-3 (ovarian) and SF2-95 (CNS) tumor cells.
Catalytic α-Deracemization of Ketones Enabled by Photoredox Deprotonation and Enantioselective Protonation
Zhang, Chenhao,Gao, Anthony Z.,Nie, Xin,Ye, Chen-Xi,Ivlev, Sergei I.,Chen, Shuming,Meggers, Eric
supporting information, p. 13393 - 13400 (2021/09/03)
This study reports the catalytic deracemization of ketones bearing stereocenters in the α-position in a single reaction via deprotonation, followed by enantioselective protonation. The principle of microscopic reversibility, which has previously rendered this strategy elusive, is overcome by a photoredox deprotonation through single electron transfer and subsequent hydrogen atom transfer (HAT). Specifically, the irradiation of racemic pyridylketones in the presence of a single photocatalyst and a tertiary amine provides nonracemic carbonyl compounds with up to 97% enantiomeric excess. The photocatalyst harvests the visible light, induces the redox process, and is responsible for the asymmetric induction, while the amine serves as a single electron donor, HAT reagent, and proton source. This conceptually simple light-driven strategy of coupling a photoredox deprotonation with a stereocontrolled protonation, in conjunction with an enrichment process, serves as a blueprint for other deracemizations of ubiquitous carbonyl compounds.
Engineering an iridium-containing metal-organic molecular capsule for induced-fit geometrical conversion and dual catalysis
Li, Xuezhao,Wu, Jinguo,Chen, Liyong,Zhong, Xiaoming,He, Cheng,Zhang, Rong,Duan, Chunying
supporting information, p. 9628 - 9631 (2016/08/04)
By introducing photoactive fac-tris(2-phenylpyridine)iridium moieties as a ligand backbone to constrain the coordination geometry of cobalt ions, a multifunctional Ir2Co3-type capsule was achieved and showed induced-fit capsule-capsule conversion by cooperative binding one carbonate anion with the equatorial Co(ii) centers. The capsule combined photocatalysis and transition metal activation synergistically and exhibited efficient catalytic ability on visible light-activated α-trichloromethylation.
