Efficient TMG catalyzed synthesis of 1,2,3-triazoles

Design and synthesis of new 1,2,3-triazole derivatives as VEGFR-2/telomerase downregulatory candidates endowed with apoptotic potential for cancer treatment

In this current work, we dedicated efforts to designing and synthesizing new 1,2,3-triazole-analogues (5a-d), (6a-d), and (7a-c) to act as dual VEGFR-2 and telomerase inhibitors with promising apoptotic potential. The synthesized analogues were examined against eleven diverse types of cancer cells and two normal cells to assess their ability to inhibit cell growth (GI%). Obviously, compound 7b showed the best average GI% (75.69 %) surpassing the average GI% of Dox (65.79 %). Compound 5d showed the lowest IC50 values (25.86 and 51.91 µM) against HNO-97 and FaDu cancer cells, respectively. Besides, compound 5a exhibited the lowest IC50 value (15.46 µM) against HCT116, whereas compound 6b revealed the lowest IC50 value (31.14 µM) against HuH7. Besides, candidates 5a, 5b, 5d, and 7a showed prominent inhibitory results towards VEGFR-2 protein with decreasing its expression by 0.33, 0.42, 0.38 and 0.26-fold change, respectively. However, compounds 5a, 5b, 5d, and 7a showed promising inhibitory results towards telomerase protein and decreased its expression by 0.60, 0.50, 0.52, and 0.44-fold change, respectively. Additionally, it was clear that compound 5a was able to upregulate the expression of Caspases 3, 8, and 9 proteins by 2.19, 1.83, and 1.62-fold change, respectively. Besides, 5a was able to downregulate the expression of CDK-2, CDK-4, and CDK-6 proteins by 0.50, 0.43, and 0.13-fold change, respectively. Obviously, compound 5a halted the cell cycle at the G1, S, and G2-M phases in HCT116 cells. Subsequently, the synthesized 1,2,3-triazole analogues can be treated as lead VEGFR-2 and telomerase inhibitors with potential apoptotic activity for future optimization and cancer treatment.

Dual EGFR and telomerase inhibitory potential of new triazole tethered Schiff bases endowed with apoptosis: design, synthesis, and biological assessments

Many cancers have displayed resistance to chemotherapeutic drugs over the past few decades. EGFR has emerged as a leading target for cancer therapy via inhibiting tumor angiogenesis. Besides, studies strongly suggest that blocking telomerase activity could be an effective way to control the growth of certain cancer cells. Based on the fact that multi-target design rationale can afford candidates with greater treatment effectiveness. Besides, it was evidenced that inhibition of human telomerase enhances the effect of some tyrosine kinase inhibitors. So, in the current work, we aimed to design and synthesize novel 1,2,3-triazole-tethered Schiff bases (5a-l) to act as dual EGFR and telomerase inhibitors. Growth inhibition (GI)% was conducted for the synthesized compounds using a panel of eleven cancer cell lines as well as two normal cell lines. Interestingly, compound 5e displayed the highest mean GI% (76.78%) among the investigated compounds surpassing the mean GI% of the reference drug doxorubicin (65.79%). In addition, compound 5g displayed notably the lowest IC50 values (13.31, 13.31, 12.62, and 31.19 μM) for the four utilized cancer cell lines HNO97, HCT116, A375, and HEPG2, respectively. Interestingly, the investigated compounds exhibited significant inhibitory potential to EGFR and telomerase protein expression; in particular, compound 5g recorded inhibitory potentials of 3.45 and 1.31 ng mL-1, respectively. Hence, protein expression of the apoptosis-related proteins was carried out for compound 5g. Pro-apoptotic proteins (caspases 3, 8, and 9) were upregulated by 1.35, 1.55, and 1.51-fold change, respectively. Meanwhile, the anti-apoptotic proteins (CDK-2, CDK-4, and CDK-6) were downregulated by 2.91, 2.01, and 9.15-fold change, respectively, ensuring the apoptotic potential of compound 5g. Accordingly, compound 5g was selected for further investigation of its effects on cell cycle progression in A375 cancer cells. Obviously, compound 5g prompted cell cycle arrest at the G0-G1 phase. Additionally, the investigated compounds showed eligible pharmacokinetic profiles with feasible oral bioavailability. Consequently, the synthesized compounds can be treated as lead multi-target anticancer ligands for future optimization.

Recent Progress on Synthesis of Functionalized 1,5-Disubstituted Triazoles

Immediately after the invention of 'Click Chemistry' in 2002, the regioselective 1,2,3- triazole scaffolds resulted from respective organic azides and terminal alkynes under Cu(I) catalysis have been well recognized as the functional heterocyclic core at the centre of modern organic chemistry, medicinal chemistry, and material sciences. This CuAAC reaction has several notable features including excellent regioselectivity, high-to-excellent yields, easy to execute, short reaction time, modular in nature, mild condition, readily available starting materials, etc. Moreover, the resulting regioselective triazoles can serve as amide bond isosteres, a privileged functional group in drug discovery and development. More than hundreds of reviews had been devoted to the 'Click Chemistry' in special reference to 1,4-disubstituted triazoles, while only little efforts were made for an opposite regioisomer i.e., 1,5-disubstituted triazole. Herein, we have presented various classical approaches for an expeditious synthesis of a wide range of biologically relevant 1,5- disubstituted 1,2,3-triazole analogues. The syntheses of such a class of diversly functionalized triazoles have emerged as a crucial investigation in the domain of chemistry and biology. This tutorial review covers the literature assessment on the development of various synthetic protocols for the functionalized 1,5-disubstituted triazoles reported during the last 12 years.

Regiospecific Synthesis of 1,4,5-Trisubstituted 1,2,3-Triazoles via Enolate–Azide Cycloaddition between 1,3-Dicarbonyl Compounds and Aryl Azides

A cycloaddition reaction at room temperature between aryl azides and 1,3-dicarbonyl compounds in the presence of potassium carbonate in dimethylsulphoxide yielded 10 4-ethoxycarbonyl-1-aryl-5-methyl-1 H-1,2,3-triazoles and seven other closely-related compounds. The 1,2,3-triazoles, nine of which are new, were obtained in good to high yields and only the 1,4-regioisomers were formed.

A general metal-free route towards the synthesis of 1,2,3-triazoles from readily available primary amines and ketones

An unprecedented approach that enables the direct and selective preparation of 1,5-disubstituted 1,2,3-triazoles from abundantly available building blocks such as primary amines, enolizable ketones and 4-nitrophenyl azide as a renewable source of dinitrogen via an organocascade process has been developed. Furthermore, this efficient methodology also enables the synthesis of fully functionalized and fused N-substituted heterocycles.

An organocatalytic azide-aldehyde [3+2] cycloaddition: high-yielding regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles

An organocatalytic azide-aldehyde [3+2] cycloaddition (organo-click) reaction of a variety of enolizable aldehydes is reported. The organo-click reaction is characterized by a high rate and regioselectivity, mild reaction conditions, easily available substrates with simple operation, and excellent yields with a broad spectrum of substrates. It constitutes an alternative to the previously known CuAAC, RuAAC, and IrAAC click reactions.

An efficient one-pot strategy for the highly regioselective metal-free synthesis of 1,4-disubstituted-1,2,3-triazoles

A simple and efficient metal-free methodology for the regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles by applying a novel inverse electron-demand-1,3-dipolar cycloaddition approach has been developed.