58259-33-9Relevant articles and documents
Effect of the ancillary ligand in N-heterocyclic carbene iridium(III) catalyzed N-alkylation of amines with alcohols
Feng, Xinshu,Huang, Ming
, (2021/06/21)
A series of air-stable N-heterocyclic carbene (NHC) Ir(III) complexes (Ir1-6), bearing various combinations of chlorine, pyridine and NHC ligands, were assayed for the N-alkylation of amines with alcohols. It was found that Ir3, with two monodentate 1,3-bis-methyl-imidazolylidene (IMe) ligands, emerged as the most active complex. A large variety of amines and primary alcohols were efficiently converted into mono-N-alkylated amines in 53–96% yields. As a special highlight, for the challenging MeOH, selective N-monomethylation could be achieved using KOH as a base under an air atmosphere. Moreover, this catalytic system was successfully applied to the gram-scale synthesis of some valuable compounds.
Novel pyrazolo[4,3-d]pyrimidine microtubule targeting agents (MTAs): Synthesis, structure–activity relationship, in vitro and in vivo evaluation as antitumor agents
Islam, Farhana,Quadery, Tasdique M.,Bai, Ruoli,Luckett-Chastain, Lerin R.,Hamel, Ernest,Ihnat, Michael A.,Gangjee, Aleem
, (2021/04/12)
The design, synthesis, and biological evaluation of a series novel N1?methyl pyrazolo[4,3-d]pyrimidines as inhibitors of tubulin polymerization and colchicine binding were described here. Synthesis of target compounds involved alkylation of the pyrazolo scaffold, which afforded two regioisomers. These were separated, characterized and identified with 1H NMR and NOESY spectroscopy. All compounds, except 10, inhibited [3H]colchicine binding to tubulin, and the potent inhibition was similar to that obtained with CA-4. Compounds 9 and 11–13 strongly inhibited the polymerization of tubulin, with IC50 values of 0.45, 0.42, 0.49 and 0.42 μM, respectively. Compounds 14–16 inhibited the polymerization of tubulin with IC50s near ～1 μM. Compounds 9, 12, 13 and 16 inhibited MCF-7 breast cancer cell lines and circumvented βIII-tubulin mediated cancer cell resistance to taxanes and other MTAs, and compounds 9–17 circumvented Pgp-mediated drug resistance. In the standard NCI testing protocol, compound 9 exhibited excellent potency with low to sub nanomolar GI50 values (≤10 nM) against most tumor cell lines, including several multidrug resistant phenotypes. Compound 9 was significantly (P 0.0001) better than paclitaxel at reducing MCF-7 TUBB3 (βIII-tubulin overexpressing) tumors in a mouse xenograft model. Collectively, these studies support the further preclinical development of the pyrazolo[4,3-d]pyrimidine scaffold as a new generation of tubulin inhibitors and 9 as an anticancer agent with advantages over paclitaxel.
Electrochemical and direct C-H methylthiolation of electron-rich aromatics
Wu, Yaxing,Ding, Hongliang,Zhao, Ming,Ni, Zhong-Hai,Cao, Jing-Pei
, p. 4906 - 4911 (2020/08/25)
The electrochemical-induced C-H methylthiolation of electron-rich aromatics has been accomplished via a three component cross-coupling strategy. Potassium thiocyanate (KSCN) as both the supporting electrolyte and sulfur source and methanol as the methylation reagent are used. This protocol is versatile for various (hetero)aromatic compounds such as aniline, anisole and indole. The reaction proceeds under mild conditions without any metal catalyst, exogenous oxidant and highly toxic sulfur reagent. Importantly, such an electrochemical-induced methylthiolated reaction could be easily scaled up with good efficiency.
