One-pot synthesis of 5-sulfonamidopyrazole from terminal alkynes, sulfonyl azides and hydrozones

A relay ring-closing metathesis/Diels-Alder approach to sugar-derived pluramycin-hybrids

Herein, we present a general approach for synthesizing pluramycin hybrids, which are analogous to the pluramycinone carbocyclic skeleton. This method involves a sequence of relay ring-closing enyne metathesis, Diels-Alder and oxidative aromatization reactions to synthesize pluramycinone-sugar hybrids. As part of our ongoing research, we have successfully synthesized two pluramycin hybrid analogues by carefully monitoring the late-stage oxidative aromatization steps, which depend on the stereo-orientation of the Diels-Alder cycloadduct at the C-4 center. The undesired ring-opening product can also serve as a C-glycoside analog, providing a versatile convergent route to access both types of hybrids and highlighting the significance of this strategy.

Beyond 1,2,3-triazoles: Formation and Applications of Ketemines Derived from Copper Catalyzed Azide Alkyne Cycloaddition

Ketemines represent an interesting class of organic intermediates that has undergone a regrowth as a consequence of recent extensions of copper catalyzed azide alkyne cycloaddition (Cu- AAC) to other synthetic fields. This review summarizes the most recent generation methods of ketimines from CuAAC reaction, highlighting chemical properties focused on the synthesis of cyclic compounds, among others, affording a general outlook towards the development of new biologically active compounds.

Discovery of Anticancer Agents from 2-Pyrazoline-Based Compounds

As nitrogen-containing five-membered heterocyclic structural units, the substituted pyrazole derivatives have a broad spectrum of pharmacological activities, especially 4,5-dihydro-1H-pyrazoles that also commonly known as 2-pyrazolines. Since 2010, considerable studies have been found that the 2-pyrazoline derivatives possess potent anticancer activities. In the present review, it covers the pyrazoline derivatives reported by literature from 2010 till date (2010-2019). This review aims to establish the relationship between the anticancer activities variation and different substituents introduced into a 2-pyrazoline core, which could provide important pharmacophore clues for the discovery of new anticancer agents containing 2-pyrazoline scaffold.

One-pot synthesis of hydrazono-sulfonamide adducts using Cu(BTC) MOF catalyst and their remarkable AIEE properties: unprecedented copper(ii)-catalyzed generation of ketenimine

One pot & simple operation; short reaction time; no column purification; very less catalyst loading; scalable.

Copper(I)-catalyzed multicomponent reaction providing a new access to fully substituted thiophene derivatives

Readily available triethylammonium 1-(2-oxoindolin-3-ylidene)-2-aroylethanethiolates are efficiently converted into a variety of fully substituted thiophene derivatives by copper(I)-catalyzed denitrogenative reactions with terminal alkynes and N-sulfonyl azides. This new reaction simultaneously installs C-N, C-S, and C-C bonds, allowing direct formation of highly functionalized thiophenes with a wide diversity in substituents in a one-pot manner. A plausible mechanism for the domino process is proposed.

Synthesis, characterization, and evaluation of a novel inhibitor of WNT/β-catenin signaling pathway

Background

Wnt/β-catenin signaling is a highly conserved pathway in organism evolution and is important in many biological processes. Overactivation of Wnt/β-catenin signaling is closely related to tumor development and progression. To identify potent small molecules that can fight aberrant Wnt/β-catenin-mediated cancer, we synthesized a novel pyrazoline derivative (N-(4-hydroxybenzyl)-1,3,4-triphenyl-4,5-dihydro-1H-pyrazole-5-carboxamide, BHX) to block Wnt signaling, and determined the absolute configuration of its precursor (ethyl 1,3,4-triphenyl-4,5-dihydro-1H-pyrazole-5-carboxylate). We then evaluated the inhibitory effect of BHX in vitro and in vivo.

Results

Cell proliferation was assessed in three human cancer cell lines (A549, HT29, and MGC803) in the presence and absence of BHX using MTS assays. BHX effectively inhibited A549, HT29, and MGC803 cell proliferation with IC₅₀ of 5.43 ± 1.99, 6.95 ± 0.24, and 7.62 ± 1.31 μM, respectively. BHX significantly induced apoptosis and G1 phase arrest in A549 and MGC803 cells. The β-catenin protein level was markedly reduced in A549 and MGC803 cells under BHX treatment. The inhibitory effect of BHX in vivo was investigated using a mouse xenograft model. A549 xenograft growth was suppressed by 50.96% in nude mice treated continuously with 100 mg/kg BHX for 21 d. Weight remained almost unchanged, which indicates the low toxicity of the compound.

Conclusions

Our data suggest that BHX is a new drug candidate for cancer treatment because of its potent effect on the Wnt/β-catenin pathway and low toxicity.

Copper-catalyzed cascade preparation of dihydropyrimidin-4-ones from N-(prop-2-yn-1-yl)amides and azides

Dihydropyrimidin-4-ones were efficiently synthesized from copper catalyzed reaction between N-(prop-2-yn-1-yl)amides and sulfonylazides under mild conditions in moderate to excellent yields (up to 96% yields). The cascade process involves the copper-catalyzed alkyne-azide cycloaddition, the formation of ketenimine intermediate, the intramolecular nucleophilic addition of ketenimine, and subsequent rearrangement.

A hybrid approach to new molecular scaffolds

Our various efforts toward the synthesis of a set of novel sugar hybrid scaffolds of several biologically active natural products such as taxol, steroids, β-lactams, and otteliones are presented. We have shown the application of the hybrid approach to design and rapidly generate a library of novel natural product-like compounds, which may have interesting biological features, using metathesis and/or cycloaddition reactions as key steps.