Exploiting the Electrophilic and Nucleophilic Dual Role of Nitrile Imines: One-Pot, Three-Component Synthesis of Furo[2,3-d]pyridazin-4(5H)-ones

Highly diastereoselective cascade dearomatization of 3-(2-isocyanoethyl)indoles with nitrile imines: a facile access to unexpected polycyclic indolines

A novel cascade annulation between 2-isocyanoethylindoles and hydrazonyl chlorides has been realized to assemble a variety of unexpected polycyclic indoline derivatives with excellent diastereoselectivities under simple reaction conditions.

Regioselective Synthesis of 5-Trifluoromethylpyrazoles by [3 + 2] Cycloaddition of Nitrile Imines and 2-Bromo-3,3,3-trifluoropropene

A general and practical method for the synthesis of 5-trifluoromethylpyrazoles is reported that occurs by the coupling of hydrazonyl chlorides with environmentally friendly and large-tonnage industrial feedstock 2-bromo-3,3,3-trifluoropropene (BTP). This exclusively regioselective [3 + 2] cycloaddition of nitrile imines and with BTP is catalyst-free and operationally simple and features mild conditions, high yields, gram-scalable, a broad substrate scope, and valuable functional group tolerance. Significantly, our method has been applied for the synthesis of the key intermediate of an active agonist of sphingosine 1-phosphate receptor.

[3 + 2] Cycloaddition of Nitrile Imines with Enamides: An Approach to Functionalized Pyrazolines and Pyrazoles

An efficient [3 + 2] cycloaddition of in situ generated nitrile imines with enamides has been established. A wide range of functionalized pyrazoline derivatives (53 examples) were obtained in moderate to good yields (up to 96%) under very mild conditions. This protocol features broad substrate scope, good functional group tolerance, and operational simplicity. Practical transformation of the products into useful pyrazoles via a one-pot process and the scalability of this protocol highlight the utility of this synthetic methodology.

Synthesis, spectroscopy, crystal structure, TGA/DTA study, DFT and molecular docking investigations of (E)-4-(4-methylbenzyl)-6-styrylpyridazin-3(2H)-one

In this study, we present the synthesis of novel pyridazin-3(2H)-one derivative namely (E)-4-(4-methylbenzyl)-6-styrylpyridazin-3(2H)-one (MBSP). The chemical structure of MBSP was characterized using spectroscopic techniques such as FT-IR, ¹H NMR, ¹³C NMR, UV-Vis, ESI-MS, and finally, the structure was confirmed by single X-ray diffraction studies. The DFT calculation was performed to compare the gas-phase geometry of the title compound to the solid-phase structure of the title compound. Furthermore, a comparative study between theoretical UV-Vis, IR, ¹H- and ¹³C NMR spectra of the studied compound and experimental ones have been carried out. The thermal behavior and stability of the compound were analyzed by using TGA and DTA techniques which revealed that the compound is thermostable up to its melting point. Finally, the in silico docking and ADME studies are performed to investigate whether MBSP is a potential therapeutic for COVID-19.

A synthesis of N-(1H-pyrazol-5-yl)-1,3,4-thiadiazol-2(3H)-imines from nitrile imines and Erlenmeyer thioazlactones

Erlenmeyer thioazlactones are reacted with hydrazonoyl chlorides in the presence of Et₃N to afford functionalized N-(1H-pyrazol-5-yl)-1,3,4-thiadiazol-2(3H)-imines in excellent yields. This strategy is based on a domino double 1,3-dipolar cycloaddition reaction of nitrile imines to Erlenmeyer thioazlactones, followed by the elimination of carbon monoxide and phenylmethanthiol from the initially formed cycloadducts. This method provides fast access to a variety of structurally diverse N-(1H-pyrazol-5-yl)-1,3,4-thiadiazol-2(3H)-imines. The structure of a typical product was established by X-ray crystallography.

To each his own: isonitriles for all flavors. Functionalized isocyanides as valuable tools in organic synthesis

The term functionalized isocyanides refers to all those isocyanides in which a neighbouring functional group can finely tune the reactivity of the isocyano group or can be exploited in post-functionalization processes. In this manuscript, we have reviewed all the isocyanides in which the pendant functional group causes either deviation from or reinforces the normal reactivity of the isocyano group and categorized them to highlight their common features and differences. An analysis of their synthetic potential and the possible unexplored directions for future research studies is also addressed.

Targeting the BCL2 Gene Promoter G-Quadruplex with a New Class of Furopyridazinone-Based Molecules

Targeting of G-quadruplex-forming DNA in the BCL2 gene promoter to inhibit the expression of anti-apoptotic Bcl-2 protein is an attractive approach to cancer treatment. So far, efforts made in the discovery of molecules that are able to target the BCL2 G-quadruplex have succeeded mainly in the identification of ligands with poor drug-like properties. Here, a small series of furo[2,3-d]pyridazin-4(5H)-one derivatives were evaluated as a new class of drug-like G-quadruplex-targeting compounds. Biophysical studies showed that two derivatives could effectively bind to BCL2 G-quadruplex with good selectivity. Moreover, one such ligand was found to appreciably inhibit BCL2 gene transcription, with a substantial decrease in protein expression levels, and also showed significant cytotoxicity toward the Jurkat human T-lymphoblastoid cell line.

Computer-Aided Identification and Lead Optimization of Dual Murine Double Minute 2 and 4 Binders: Structure-Activity Relationship Studies and Pharmacological Activity

The function of p53 protein, also known as "genome guardian", might be impaired by the overexpression of its primary cellular inhibitor, the murine double minute 2 protein (MDM2). However, the recent finding that MDM2-selective inhibitors induce high levels of its homologue MDM4, prompt us to identify, through a receptor-based virtual screening on an in house database, dual MDM2/MDM4 binders. Compound 1 turned out to possess an IC₅₀ of 93.7 and of 4.6 nM on MDM2 and MDM4, respectively. A series of compounds were synthesized to optimize its activity on MDM2. As a result, compound 12 showed low nanomolar IC₅₀ for both targets. NMR studies confirmed the pocket of binding of 12 as predicted by the Glide docking software. Notably, 12 was able to cause concentration-dependent inhibition of cell proliferation, yielding an IC₅₀ value of 356 ± 21 nM in neuroblastoma SHSY5Y cells and proved even to efficiently block cancer stem cell growth.

Isocyanide-based multicomponent reactions in the synthesis of heterocycles

In this review, we update our previous presentation, underscoring the recent applications of isocyanides as privileged synthons in the synthesis of various heterocyclic compounds, especially focused on those synthesizedviamulticomponent reactions.

An efficient synthesis of 1-arylindazole-3-carboxamides using nitrile imines, isocyanides and 2-hydroxymethylbenzoic acid, followed by a chemoselective Buchwald–Hartwig intramolecular cyclization

A convergent, efficient and regio-selective two-step synthesis of pharmaceutically relevant 1-arylindazole-3-carboxamides through an isocyanide-based reaction and a Buchwald–Hartwig cyclization.