41419-59-4Relevant articles and documents
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.
Recyclable covalent triazine framework-supported iridium catalyst for the N-methylation of amines with methanol in the presence of carbonate
Liu, Peng,Yang, Jiazhi,Ai, Yao,Hao, Shushu,Chen, Xiaozhong,Li, Feng
, p. 281 - 290 (2021/03/26)
An iridium complex Cp*Ir@CTF, which is synthesized by the coordinative immobilization of [Cp*IrCl2]2 on a functionalized covalent triazine framework (CTF), was found to be a general and highly efficient catalyst for the N-methylation of amines with methanol in the presence of carbonate. Under environmentally benign conditions, a variety of desirable products were obtained in high yields with complete selectivities and functional group friendliness. Furthermore, the synthesized catalyst could be recycled by simple filtration without obvious loss of catalytic activity after sixth cycle. Notably, this research exhibited the potential of covalent triazine framework-supported transition metal catalysts for hydrogen autotransfer process.
Transition-Metal-Free and Visible-Light-Mediated Desulfonylation and Dehalogenation Reactions: Hantzsch Ester Anion as Electron and Hydrogen Atom Donor
Heredia, Micaela D.,Guerra, Walter D.,Barolo, Silvia M.,Fornasier, Santiago J.,Rossi, Roberto A.,Budén, Mariá E.
, p. 13481 - 13494 (2020/12/15)
Novel approaches for N- and O-desulfonylation under room temperature (rt) and transition-metal-free conditions have been developed. The first methodology involves the transformation of a variety of N-sulfonyl heterocycles and phenyl benzenesulfonates to the corresponding desulfonylated products in good to excellent yields using only KOtBu in dimethyl sulfoxide (DMSO) at rt. Alternately, a visible light method has been used for deprotection of N-methyl-N-arylsulfonamides with Hantzsch ester (HE) anion serving as the visible-light-absorbing reagent and electron and hydrogen atom donor to promote the desulfonylation reaction. The HE anion can be easily prepared in situ by reaction of the corresponding HE with KOtBu in DMSO at rt. Both protocols were further explored in terms of synthetic scope as well as mechanistic aspects to rationalize key features of desulfonylation processes. Furthermore, the HE anion induces reductive dehalogenation reaction of aryl halides under visible light irradiation.
