Transition metal free thioarylation, selenoarylation and arylation of 2-aminomaleimide, using thiophenols, diaryl diselenides and arylhydrazine hydrochlorides respectively, has been reported in DMSO ...under aerobic condition in presence of K2CO3 at room temperature. The reaction occurs smoothly without prerequisite N-protection of 2-aminomaleimide. The synthesis of novel, polyfunctionalized maleimides has been achieved by the direct C–H activation of enamines. Thioarylation and selenoarylation are proposed to be proceeding via disulfides/diselenides and arylation has been proposed to be proceeding via aryl free radicals.
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•Transition metal free thioarylation, selenoarylation and arylation of 2-aminomaleimide has been reported.•We develop a novel K2CO3/DMSO reagent for thioarylation, selenoarylation for different substrates.•This methodology is provides general, green and efficient methods for thioarylation.•A novel method for synthesis of polyfunctionalized maleimides.•Thioarylation, selenoarylation and arylation of 2-aminomaleimide has been reported at room temperature in high yields.
A novel thiadiazole functionalized schiff base chemoreceptor (E)-2,4-dichloro-6-(((5-mercapto-1,3,4-thiadiazol-2-yl)imino)methyl)phenol
(SB-1)
has been synthesized and characterized spectroscopically ...by using various techniques. Its photophysical behaviour was scanned towards a variety of metal ions in mixed aqueous media. The chemosensor
(SB-1)
displayed excellent selectivity towards Cu
2+
ion through fluorescent diminishment (turn-off phenomenon). Colorimetric analyses showed a rapid colour change from yellow to dark red under visible light upon addition of Cu
2+
ions. Interestingly, the original yellow colour reappeared back instantly after the addition of EDTA
2−
anions, thus confirming the reversible nature of
SB-1
. Competitive experiments validated no interference from the other co-existing metal ions in the recognition process of
SB-1
towards Cu
2+
ion. Job’s plot confirmed 1:1 binding stoichiometry between
SB-1
and Cu
2+
ion with the binding constant value of 3.87 × 10
4
M
− 1
. The limit of detection was determined to be 1.01 × 10
− 7
M suggesting good sensitivity of
SB-1
towards Cu
2+
ions. Furthermore, pH-dependent UV-Vis spectral behaviour of
SB-1
confirmed that it could act as an effective optical pH-sensor for highly acidic environment as well. Portable nature of probe
SB-1
was explored by fabricating “easy-to-use” paper test strips, which allow robust and rapid detection of Cu
2+
ions. Based on the multi-responsive properties of
SB-1
, a ‘NOR’ logic gate was constructed by applying Cu
2+
and EDTA
2−
as chemical inputs (ln1: Cu
2+
, ln2: EDTA
2−
) while emission intensity observed at 560 nm was considered as output signal (O1). DFT optimized geometries confirmed that chemosensor
SB-1
exists in Azo form (Enol form) in its ground state. Molecular docking of the
SB-1
and its copper complex, into the binding site of TRK protein tyrosine kinase (PDB: 1t46) was also carried out to explore their biological activity and their potential use as TRK inhibitors.
Advancement in nanotechnology supports system development to achieve rapid, affordable, and intelligent health management and has raised the urgent demand to explore multimodel affordable metal oxide ...nanostructures with the features of biocompatible tunable performance and scaled‐up processing. Keeping this as a motivation, zirconia nanostructures (Zr‐NSs) are emerging as nanostructures of choice for advanced biomedical applications due to affordable, scalable production, easy surface modifications, tunable surface morphology, multiphase stability, and acceptability by biological features such as biocompatibility, viability for bioactives, and a high isoelectric point of 9.5. Zr‐NSs, alone and in the form of hybrids, and nanocomposites have demonstrated notable high performance to develop next‐generation biosensors, implanted materials, and bioelectronics. However, their excellent salient features toward high‐performance biomedical system development are not well articulated in the form of a review. To overcome this knowledge gap, herein an attempt is made to summarize state‐of‐the‐art Zr‐NS preparation techniques as per targeted applications, surface functionalization of Zr‐NSs to achieve desired properties, and applications of Zr‐NSs in the field of biomedicine for health wellness. The challenges, possible solutions, and authors’ viewpoints considering prospects in mind are also part of this report.
Herein, advanced high‐performance bio‐medical applications of surface‐functionalized multimodel zirconia nanostructures (Zr‐NSs) are explored. Zr‐NSs (alone or as hybrids) are demonstrating outstanding performance to develop next generation biosensors, implanted materials, and bioelectronics due to affordable scalable production, ease of surface modifications, tunable surface properties, multiphase stability, and acceptable biological features such as a high isoelectric point, biocompatibility, and viability toward bioactives.
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•Multicomponent one-pot synthesis of spiro isoquinoline conjugates.•Metal and Catalyst free synthesis.•High Yields of the products at room temperature.•Anticancer activity against ...breast cancer (MCF-7 cancer line)•Best IC50 value of 98.8 μM.
Quinoline derived scaffolds have long been reported for their promising biological responses such as anti-Alzheimer, antituberculosis, antioxidants, anti-inflammatory etc. Pyrimidine, a versatile pharmacophore, has also been employed for developing a variety of bioactive molecules. Therefore, we envisioned to incorporate these two privileged moieties into a single one for improved biological applications. In this work, we developed an efficient catalyst free synthesis of spiroisoquinlino-pyrimidine conjugates via one-pot multicomponent reaction of various 1,3-dicarbonyls, isoquinoline and dialkyl acetylene dicarboxylates. We further evaluated antiproliferative activity of all the compounds against MCF-7 human breast cancer cells. Out of several compounds synthesized, three compounds IVc, IVg and IVi having substituent methyl and dioxyl ring in molecule have shown potent anticancer activity. The most potent cytotoxic compound against breast cancer cells in our study was found to be IVi with IC50 value of 98.8 μM.
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•A rhodamine-labelled tripeptide was synthesized and spectroscopically characterized.•It self-assembled to form spherical nanoaggregates in H2O-ACN mixture (fw = 80 %).•It holds a ...fast response time (≤15 s) and low LOD (51 nm) towards Al3+ ions.•Test-strips, thin-films, and Arduino-based optosensing platform were fabricated.
Peptide-fluorophore conjugates (PFCs) have been expeditiously utilized for metal ion recognition owing to their distinctive characteristics. Selective detection and quantification of aluminum is essential to minimize health and environmental risks. Herein, we report the synthesis and characterization of a new chemoprobe with aggregation-induced emission characteristics by chemically conjugating rhodamine-B fluorophore with a tripeptide. The probe revealed β-sheet secondary conformation in both solid and solution states, as confirmed by FT-IR, PXRD, and CD experiments. AIE characteristics of the probe in water-MeCN mixtures revealed the formation of spherically shaped nanoaggregates with an average size of 353 ± 7 nm, as confirmed by SEM, TEM, and DLS studies. The probe exhibited a large stokes shift (175 nm) and displayed selective colorimetric and fluorometric responses towards Al3+ ions with an extremely low detection limit (51 nm) and a fast response time (≤15 s). Comparative NMR studies confirmed the cleavage of spirolactam ring upon aluminum binding. The probe’s practicality was enhanced through integration into test strips and thin films, allowing solid-phase detection of Al3+ ions. Furthermore, an RGB-Arduino enabled optosensing device has been developed to enable instant quantifiable analysis of aluminum concentrations in real-time conditions.
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•Two quinoline-ampyrone functionalized azo dyes 6QD and 8QD have been synthesized and characterized.•6QD and 8QD confirmed their selective switch-on behaviour towards Al3+ and Co2+ ...ions, respectively.•The emission intensity of 6QD enhanced due to CHEF and PET effect while emission behaviour of 8QD operates on CHEF and ICT.•Job’s plot confirmed 1:1 binding stoichiometry for complexes 6QD-Al3+ and 8QD-Co2+.•pH based absorption studies confirmed the naked eye colour change of solutions of both probes in highly basic conditions (pH > 9).
Two azo dyes (E)-4-((6-hydroxyquinolin-5-yl)diazenyl)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (6QD) and (E)-4-((8-hydroxyquinolin-5-yl)diazenyl)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (8QD) have been designed and synthesized. The structure of both dyes was confirmed by FTIR, NMR spectroscopy and mass spectrometry. The absorption and emission spectral analysis of 6QD and 8QD confirmed their selective turn-on behaviour towards Al3+ and Co2+ ions, respectively in MeOH:H2O (v/v = 1:1, HEPES buffer, pH = 7.2) at room temperature. The emission intensity of 6QD enhanced remarkably by 148-fold upon binding with Al3+ ion due to chelation-enhanced fluorescence (CHEF) effect and inhibition of photoinduced electron transfer (PET) phenomenon in the molecule. Emission behaviour of 8QD operates on CHEF and intramolecular charge transfer (ICT) mechanisms in presence of Co2+ ion which induced 26-fold enhancement in emission intensity of 8QD. Colorimetric studies showed prominent visual response for Al3+ and Co2+ ions allowing the real time analysis of these ions in their corresponding solutions. Other coexisting metal ions do not interfere with the detection of these metal ions. Job’s plot analyses revealed 1:1 binding stoichiometry for complexes 6QD-Al3+ and 8QD-Co2+. Association constants of complexes 6QD-Al3+ and 8QD-Co2+ were found to be 1.2 × 106 and 4 × 106 M−1, respectively which suggest good association of both probes with respective metal ions. The limit of detection of 6QD and 8QD was determined to be 1 × 10−8 M and 9.1 × 10−8 M respectively, which demonstrates the high sensitivity towards corresponding metal ions. Reversible studies confirmed that both probes 6QD and 8QD could be used as secondary sensor for EDTA2− anion. Furthermore, pH based absorption studies revealed that 6QD and 8QD can act as naked eye colorimetric probe for detection of hydroxyl ions at pH > 9.
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•A rhodamine functionalized azo-phenol derivative (1) has been designed and synthesized.•Selective detection of Th4+ ions up to nano molar level in semi-aqueous media by ‘OFF-ON’ ...mechanism.•1-Th4+ complex as a secondary sensor for oxalate and chromate ions.•Sensitive and reversible for highly acidic environment (pH < 4) as well with a pKa value of 2.01.•These characteristics of 1 have been implied in the construction of multiple logic gates.
A new rhodamine functionalized Schiff base (3′,6′-bis(diethylamino)-2-((Z)-(5-((E)-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)diazenyl)-2,4-dihydroxybenzylidene) amino)spiroisoindoline-1,9′-xanthen-3-one (1) has been synthesized and was characterized spectroscopically. The optical properties of the schiff base have been studied using UV–vis and fluorescence spectra. Schiff base 1 displayed a selective behaviour towards Th4+ ions, as evidenced by UV–vis and fluorescence spectra. It shows visible colour change from orangish-yellow to red upon addition of Th4+ ions. A strong new emission band at 586 nm and about 24-fold enhancement in fluorescence intensity was observed upon binding with Th4+ which could be quenched by subsequent addition of oxalate and chromate ions. Probe 1 also acts as a reversible pH sensor in the highly acidic region (pH < 4, pKa = 2.01) via the photophysical response to pH as well as visible detectable colour change from orangish-yellow to red to pink. The absorbance and emission intensities of 1 diminished in the pH region from 4 to 11.5 and could be recovered by adding acid to adjust the pH < 4. Probe 1 exhibited high binding constant (8.595 × 106 M−1) and low limit of detection (1.122 × 10-9) compared to most previously reported sensors for Th4+ ions. Furthermore, two multiple logic gates i.e. 3 and 5 input, have been constructed.
Coumarin scaffolds exhibit diversified biological responses such as anticancer, anti‐Alzheimer, anticogulants, antituberculosis, antioxidants, anti‐inflammatory etc. 1,3‐Oxazines also possess wide ...range of pharmacological activities. Therefore, incorporation of these two privileged scaffolds in a single entity using efficient green methodologies would be of great importance.Herein, we report a facile, efficient and catalyst free synthesis of coumarin functionalized bis‐oxazines via one‐pot condensation of 5,7‐dihydroxy‐4‐methyl‐2H‐chromen‐2‐one, substituted aromatic amines and formaldehyde in ethanol at room temperature. This domino reaction provides rapid access to pharmacologically relevant molecular hybrids in short reaction time. This protocol offers advantages of mild reaction conditions, operational simplicity, avoidance of column chromatography, inexpensive starting reactants and ease of product separation.
We report facile and catalyst free synthesis of coumarin functionalized bis‐oxazines via one‐pot condensation of 5,7‐dihydroxy‐4‐methyl‐2H‐chromen‐2‐one, substituted aromatic amines and formaldehyde in ethanol at room temperature. All the reactions proceeded smoothly without employing any purification technique thus making it a sustainable methodology. This environmentally benign protocol holds advantage of operational simplicity, easy workup and high yields.
A variety of 1,1-diacetates have been chemoselectively and efficiently deprotected to the corresponding aldehydes as well as deprotected and concomitantly reduced to the corresponding alcohols in ...high yields at ambient temperature with nickel boride generated in situ using different molar ratios of sodium borohydride and nickel (II) chloride in methanol at room temperature. Deprotection and reduction of a variety of aromatic, aliphatic and heterocyclic acylals have been achieved efficiently. Mild reaction conditions, easy work-up, high yields and chemoselectivity demonstrate the efficiency of this new method.
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