4,6-Dichloro-5-Nitrobenzofuroxan: Different Polymorphisms and DFT Investigation of Its Reactivity with Nucleophiles

This research focuses on the X-ray structure of 4,6-dichloro-5-nitrobenzofuroxan 1 and of some of its amino derivatives (4a, 4e, 4g, and 4l) and on DFT calculations concerning the nucleophilic reactivity of 1. We have found that by changing the solvent used for crystallization, it is possible to obtain 4,6-dichloro-5-nitrobenzofuroxan (1) in different polymorphic structures. Moreover, the different torsional angles observed for the nitro group in 1 and in its amino derivatives (4a, 4e, 4g, and 4l) are strictly dependent on the steric hindrance of the substituent at C-4. DFT calculations on the course of the nucleophilic substitution confirm the role of the condensed furoxan ring in altering the aromaticity of the carbocyclic frame, while chlorine atoms strongly influence the dihedral angle and the rotational barrier of the nitro group. These results corroborate previous observations based on experimental kinetic data and give a deep picture of the reaction with amines, which proceeds via a “non-aromatic” nucleophilic substitution.

4,7-Bis(dodecylthio)-[1,2,5]thiadiazolo[3,4-c]pyridine

Bis(alkylsulfanyl) derivatives of 1,2,5-thiadiazoles fused with aromatic and heteroaromatic rings containing long alkyl chains are of interest as compounds with liquid crystalline properties. In this communication, 4,7-bis(dodecylthio)-[1,2,5]thiadiazolo[3,4-c]pyridine 1 was obtained from 4,7-dibromo-[1,2,5]thiadiazolo[3,4-c]pyridine 2 by a combination of two reactions—aromatic nucleophilic substitution SNAr and Buchwald–Hartwig cross-coupling. The structure of the newly synthesized compounds was established by means of elemental analysis; high-resolution mass spectrometry; 1H, 13C NMR, IR and UV spectroscopy; and mass spectrometry.

Modular synthesis of carbazole substituted phthalimides as potential photocatalysts

Herein, we report the modular synthesis of carbazole functionalized phthalimides (PI), and demonstrated their applicability as catalyst in selected photocatalytic transformations. The developed synthetic approach provides high variability of phthalimide considering that the synthesis of the phthalimide core can be easily performed. Starting from fluorophthalic acid anhydrides, the corresponding fluorophthalimides were prepared with various amines, and the fluoro function ensured the introduction of carbazoles into the phthalimide framework through aromatic nucleophilic substitution. Besides the synthetic developments, we tested some of the carbazolyl phthalimides in four different photocatalytic transformations, and found attractive and comparable activity to the known 4-CzIPN and noble metal complexes.

Novel Hybrid Compounds Containing Benzofuroxan and Aminothiazole Scaffolds: Synthesis and Evaluation of Their Anticancer Activity

A series of novel hybrid compounds containing benzofuroxan and 2-aminothiazole moieties are synthesized via aromatic nucleophilic substitution reaction. Possible reaction pathways have been considered quantum-chemically, which allowed us to suggest the most probable products. The quantum chemical results have been proved by X-ray data on one compound belonging to the synthesized series. It was shown that the introduction of substituents to both the thiazole and amine moieties of the compounds under study strongly influences their UV/Vis spectra. Initial substances and obtained hybrid compounds have been tested in vitro as anticancer agents. Target compounds showed selectivity towards M-HeLa tumor cell lines and were found to be more active than starting benzofuroxan and aminothiazoles. Furthermore, they are considerably less toxic to normal liver cells compared to Тamoxifen. The mechanism of action of the studied compounds can be associated with the induction of apoptosis, which proceeds along the mitochondrial pathway. Thus, new hybrids of benzofuroxan are promising candidates for further development as anticancer agents.

Correction: Rational design of a “dual lock-and-key” supramolecular photosensitizer based on aromatic nucleophilic substitution for specific and enhanced photodynamic therapy

Correction for ‘Rational design of a “dual lock-and-key” supramolecular photosensitizer based on aromatic nucleophilic substitution for specific and enhanced photodynamic therapy’ by Kun-Xu Teng et al., Chem. Sci., 2020, 11, 9703–9711, DOI: 10.1039/D0SC01122C.

5-Nitroisoxazoles in SNAr Reactions: Access to Polysubstituted Isoxazole Derivatives

An efficient protocol for straightforward functionalization of isoxazole ring via the reactions of aromatic nucleophilic substitution of nitro group with various nucleophiles has been elaborated. The method is featured with...

Diversity-Orientated Synthesis of Macrocyclic Heterocycles Using Double SNAr Approach.

An efficient macrocyclisation approach based on the double aromatic nucleophilic substitution (SNACK) was developed. This methodology allows a facile incorporation of heterocyclic motifs into macrocyclic rings and rapid synthesis of...

Host-guest type multiple site fluorescent probe for GSH detection in living organisms

The host-guest type molecular size matching strategy which embodied intramolecular hydrogen bond, aromatic nucleophilic substitution and nucleophilic addition was utilized to develop fluorescent probe for GSH specific detection and in...