Efficient access to 1,3,4-trisubstituted pyrroles via gold-catalysed cycloisomerization of 1,5-diynes

A gold-catalysed cycloisomerization of 1,5-diynes is described, which offers a selective approach to access 1,3,4-trisubstituted pyrroles. In this reaction, the cationic gold catalyst activates the ynamide moiety, initiating the cycloisomerization to produce the pyrrole core, and H₂O acts as an external nucleophile to trap the vinyl cationic species, thus leading to the formation of 1,3,4-trisubstituted pyrroles with high selectivity.

(E)-1-(3-Benzoyl-4-phenyl-1H-pyrrol-1-yl)-3-phenylprop-2-en-1-one

Over the last decade, there has been an increasing effort to fight inflammatory conditions establishing new multitarget approaches. Chronic inflammation is implicated in many multifactorial diseases, constituting a great economic burden and a chronic health problem. In an attempt to develop new potent multifunctional anti-inflammatory agents, a cinnamic-pyrrole hybrid (6) was synthesized and screened for its antioxidant and anti-Lipoxygenase potential. The new compound, in comparison with its pyrrole precursor (4), showed improved biological activities. In silico calculations were performed to predict its drug-likeness. The examined derivative is considered orally bioavailable according to Lipinski’s rule of five. Compound 6 could be used as a lead for the synthesis of more effective hybrids.

Mechanochemical Syntheses of N-Containing Heterocycles with TosMIC

A mechanochemical van Leusen pyrrole synthesis with a base leads to 3,4-disubstitued pyrroles in moderate to excellent yields. The developed protocol is compatible with a range of electron-withdrawing groups and can also be applied to the synthesis of oxazoles. Attempts to mechanochemically convert the resulting pyrroles into porphyrins proved to be difficult.

Synthesis of Novel Aryl (4-Aryl-1H-Pyrrol-3-yl) (Thiophen-2-yl) Methanone Derivatives: Molecular Modelling, In Silico ADMET, Anti-Inflammatory and Anti-Ulcer Activities

BACKGROUND

Due to the presence of both five-membered heterocyclics like pyrrole and thiophene in one molecule considerable attention was made for their enormous pharmacological activities out of which include anti-inflammatory and anti-ulcer activities.

OBJECTIVE

Chalcones with toluenesulfonylmethyl isocyanide (TosMIC) undergo synthesis to form some new aryl (4-aryl-1H-pyrrol-3-yl) (thiophen-2-yl) methanone derivatives. Molecular docking of synthesized compounds with protein receptors of anti-inflammatory COX-1(3N8Y), COX-2 (1PXX) along with anti-ulcer H+/K+ATPase enzyme (2XZB) followed with drug-likeness, and in silico ADMET properties.

MATERIALS AND METHODS

The multicomponent reaction was carried out by the intermediate formation of α, β-unsaturated ketone from carbonyl compounds which on sequential addition undergoes [3+2] cycloaddition reaction in same medium affords aryl (4-aryl-1H-pyrrol-3-yl) (thiophen-2-yl) methanone derivatives by addition of TosMIC in basic medium had resulted in series of compounds PY1 to PY12. All the new synthesized compounds were screened for their in-vitro anti-inflammatory activity by bovine serum albumin method followe with COX assay, and in-vivo by using carrageenan-induced rat paw edema method of the selected compounds PY1, PY5 and PY12 which is also screened for anti-ulcer activity by pylorus ligation method, respectively. Molecular docking was performed using autodock tools, drug-likeness by OSIRIS property explorer and admetSAR properties.

RESULTS AND DISCUSSION

From the synthesized compounds of aryl (4-aryl-1H-pyrrol-3-yl) (thiophen- 2-yl) methanone derivatives PY5 showed decent in-vitro and in-vivo anti-inflammatory along selectivity index of 6.2 for COX-1 with IC50(μM) value of 9.54 over diclofenac with 8.74 and PY1 showed decent in-vivo anti-ulcer activities along with drug-likeness and in silico ADMET predictions revealed that all the synthesized compounds have minimal toxic effects with good absorption as well as solubility characteristics. The selected compounds may serve as potential lead compounds for developing new anti-inflammatory and anti-ulcer drugs.

CONCLUSION

From the newly synthesized molecules PY5 was found to be effective for anti-inflammatory and PY1 was found to be effective for anti-ulcer activities further derivitization and designed of modification to achieve more compounds with potent anti-inflammatory and anti-ulcer activities.

Synthesis of Multi-Substituted Pyrrole Derivatives Through [3+2] Cycloaddition with Tosylmethyl Isocyanides (TosMICs) and Electron-Deficient Compounds

Pyrrole and its polysubstituted derivatives are important five-membered heterocyclic compounds, which exist alone or as a core framework in many pharmaceutical and natural product structures, some of which have good biological activities. The Van Leusen [3+2] cycloaddition reaction based on tosylmethyl isocyanides (TosMICs) and electron-deficient compounds as a substrate, which has been continuously developed due to its advantages such as operationally simple, easily available starting materials, and broadly range of substrates, is one of the most convenient methods to synthetize pyrrole heterocycles. In this review, we discuss the different types of two carbon synthons in the Van Leusen pyrrole reaction and give a summary of the progress of these synthesis methods in the past two decades.

Zirconocene dichloride catalysed one-pot synthesis of pyrroles through nitroalkene-enamine assembly

Zirconocene dichloride was found to be a highly efficient catalyst for the synthesis of multi-substituted pyrroles by a three-component, one-pot reaction.

Arylsulfonylmethyl isocyanides: a novel paradigm in organic synthesis

p-Tosylmethyl isocyanide (TosMIC), an α-acidic isocyanide has emerged as a privileged reagent to access biologically relevant fused heterocycles and some natural products like (−)-ushikulide A, variolin B, porphobilinogen and mansouramycin B.

Rational design of a photo-crosslinking BODIPY for in situ protein labeling

We report the first rational design of a photo-crosslinking BODIPY fluorophore (pcBD) and its biological application for biomolecule labeling in a spatiotemporally controlled manner.

Silver-catalyzed cascade reaction of tosylmethyl isocyanide (TosMIC) with propargylic alcohols to (E)-vinyl sulfones: dual roles of TosMIC

An silver-catalyzed cascade reaction of tosylmethyl isocyanide (TosMIC) with propargylic alcohols for the synthesis of (E)-vinyl sulfones has been developed where TosMIC plays a dual role as both the reactant in the allenylation of propargylic alcohols and the sulfonyl source.

Reaction of α-amido sulfones with functionalized nitrocompounds: a new two-step synthesis of N-alkoxycarbonyl-2,5-disubstituted pyrroles

N-Alkoxycarbonyl-2,5-disubstituted pyrroles can be readily prepared by a new two-step procedure involving a preliminary addition of nitro ketals to α-amido sulfones followed by an acid promoted ring closure of the obtained intermediates through a cascade process.