Palladium-Catalyzed Intramolecular C-H Amination via Oxidative Coupling on Indole Derivatives: Access to 11-Benzo[4,5]imidazo[1,2-]indoles.

A novel palladium-catalyzed intramolecular C-H amination via oxidative coupling exploiting inactivated N-substituted aryl amines on indoles for the one-pot synthesis of novel 11-benzo[4,5]imidazo[1,2-]indole derivatives is reported. The optimized reaction conditions accommodated a wide range of electronic variations on both the indole and the pendant aryl amine ring, resulting in products with good to excellent yields.

Correction: An NNN Pd(II) pincer complex with 1,1-diaminoazine: a versatile catalyst for acceptorless dehydrogenative coupling reactions.

Correction for 'An NNN Pd(II) pincer complex with 1,1-diaminoazine: a versatile catalyst for acceptorless dehydrogenative coupling reactions' by Aabid A. Wani , , 2024, https://doi.org/10.

Stabilizing 4π electron pyrrolyl cations by inducing aromaticity.

The pyrrolyl cation is a 4π electron ring system which is anti-aromatic and unstable. This work reports an experimental procedure to obtain stable pyrrolyl cations. Electron donation from N-heterocyclic carbenes makes the ring stable by converting a 4π electron ring system into a 6π electron ring system.

An NNN Pd(II) pincer complex with 1,1-diaminoazine: a versatile catalyst for acceptorless dehydrogenative coupling reactions.

An azine-based, non-palindromic, neutral NNN-pincer ligand was synthesised in a single step with an yield of 85%. The palladation of the ligand, using Pd(OAc), was performed in acetonitrile at room temperature to obtain the pincer complex in 88% yield through a simple, cost-effective, and straightforward synthetic procedure. The structure of the complex was confirmed by H NMR, C NMR, FT-IR, and mass spectrometry.

Dual Signature of Chirality Induced Spin Selectivity through Spontaneous Resolution of 2D Metal-Organic Frameworks.

The Chiral-Induced Spin Selectivity (CISS) effect has emerged as a fascinating phenomenon within the realm of electron's spin manipulation, showcasing a unique interplay between electron's spin and molecular chirality. Subsequent to its discovery, researchers have been actively involved in exploring the new chiral molecules as effective spin filters. In the realm of observing the CISS effect, the conventional approach has mandated the utilization of two distinct enantiomers of chiral molecules.

Directed regioselective arylation of imidazo[1,2-]pyridine-3-carboxamides using Rh(III) catalysis.

In contrast to previously reported free-radical pathways to functionalize imidazo[1,2-]pyridines at the C-5 centre, directing group approaches are rare. Herein, we demonstrate a rhodium(III) catalyzed efficient and regioselective strategy for directed C-5 functionalization of imidazo[1,2-]pyridines using -methoxyamide as a directing group. This methodology facilitates directed arylation without the necessity for pre-functionalization.

Synthesis of Triazolo[4',5':4,5]furo[2,3-]pyridine via Post Modification of an Unusual Groebke-Blackburn-Bienaymé Multicomponent Reaction.

The Groebke-Blackburn-Bienaymé (GBB) reaction is a well-established three-component reaction for synthesizing imidazofused scaffolds from heterocyclic amidines, aldehydes, and isonitriles. However, the replacement of pyridoxal as an aldehyde component in this reaction results in the formation of the furo[2,3-]pyridine skeleton as an "unusual GBB product". Despite the interesting nature of this unusual reaction, not much work was further reported.

Surface coating induced room-temperature phosphorescence in flexible organic single crystals.

Materials exhibiting room temperature phosphorescence (RTP) are in high demand for signage, information encryption, sensing, and biological imaging. Due to weak spin-orbit coupling and other non-radiative processes that effectively quench the triplet excited states, RTP is sparsely observed in organic materials. Although the incorporation of a heavy atom through covalent or non-covalent modification circumvents these drawbacks, heavy-atom-containing materials are undesirable because of their deleterious side effects.

A comparison of the isostructural [Co(NH)NO]XNO and [Co(NH)ONO]XNO, X = Cl or Br in relation to nitro-nitrito linkage isomerization and photomechanical effects.

A new photoactive cobalt coordination compound, [Co(NH)NO]BrNO (I), was obtained. Its crystal structure was shown to be isostructural with previously known [Co(NH)NO]ClNO (II) for which linkage isomerization accompanied with mechanical response of the crystal has been already reported. Single crystals of I are transformed into nitrito isomer [Co(NH)ONO]BrNO (III) on irradiation with blue light (λ = 465 nm) without being destroyed.

A highly sensitive and specific luminescent MOF determines nitric oxide production and quantifies hydrogen sulfide-mediated inhibition of nitric oxide in living cells.

The synthesis of a novel carboxylate-type organic linker-based luminescent MOF (Zn(HL) (L)) (named PUC2) (HL = 2-aminoterephtalic acid, L = 1-(3-aminopropyl) imidazole) is reported by the solvothermal method and comprehensively characterized using single-crystal XRD, PXRD, FTIR, TGA, XPS, FESEM, HRTEM, and BET. PUC2 selectively reacts with nitric oxide (NO) with a detection limit of 0.08 µM, and a quenching constant (0.

Multifunctional BODIPY embedded non-woven fabric for CO release and singlet oxygen generation.

Materials that can simultaneously release CO and generate singlet oxygen upon visible light irradiation under ambient conditions are highly desirable for therapeutic applications. Furthermore, materials that can sequester the undesirable side products into the matrix without affecting the release of CO and singlet oxygen generation would allow them to be used for practical applications. Focussing on these aspects, we prepared two dipicolylamine appended BODIPY‑manganese(I) tricarbonyl complexes wherein the metal core was systematically tethered at 5- and 8- positions of the BODIPY core.

Metal-Free One-Pot Annulative Coupling of 2-Hydroxybenzaldehydes with β-Ketothioamides: Access to Diverse 2-Arylimino-2-Chromenes.

A concise and practical one-pot sustainable approach for expedient synthesis of 2-arylimino-2-chromenes by two-component cascade [4 + 2] annulative coupling of easily available 2-hydroxybenzaldehydes with β-ketothioamides has been developed in good yields for the first time. Remarkably, metal- and additive-free conditions, use of simple KCO as a mild base, open atmosphere, exclusive regioselectivity, step/atom economy, nonhazardous reagents, and easy purification are added characteristics to the strategy. This annulative protocol will not only provide an efficient method to access diverse chromene scaffolds, but also enrich the research domain of β-ketothioamides.

Dithiophosphonate Anchored Heterometallic (Ag(I)/Fe(II)) Molecular Catalysts for Electrochemical Hydrogen Evolution Reaction.

The dichalcogenide ligated molecules in catalysis to produce molecular hydrogen through electroreduction of water are rarely explored. Here, a series of heterometallic [Ag(SPFc(OR)] [where Fc = Fe(η-CH)(η-CH), R = Me, ; Et, ; Pr, ; Amyl, ] clusters were synthesized and characterized by IR, absorption spectroscopy, NMR (H, P), and electrospray ionization mass spectrometry. The molecular structures of , , and clusters were established by single-crystal X-ray crystallographic analysis.

Isomer Selective Thermosalience and Luminescence Switching in Organic Crystals.

Organic crystals that respond to external stimuli are interesting for the design of smart materials. Here, we show that molecular engineering can transform simple naphthalidenimine-boron complexes─known for their exciting photophysical properties─into functional materials that exhibit thermosalience and thermal-luminescence switching. Detailed crystallographic and spectroscopic investigations revealed the role of subtle molecular parameters in deciphering charge-transfer interactions, which in turn imparted dynamic properties to the crystals.

A luminescent Zn-MOF for the detection of explosives and development of fingerprints.

A luminescent 3D metal-organic framework [Zn(NDA)(AMP)] = PUC1 (where, NDA = naphthalene-2,6-dicarboxylic acid and AMP = 4-aminomethyl pyridine) was synthesized under solvothermal conditions. The synthesized 3D framework was fully characterized with the help of different analytical techniques such as SCXRD, FTIR, TGA, PXRD, SEM, BET, PUC1 exhibited a strong emission peak at 371 nm when excited at 290 nm and the resulting emission was efficiently quenched in the presence of various organic explosive substances like pentaerythritol tetranitrate (PETN), 2,4,6-trinitrophenyl--methylnitramine (Tetryl), trinitrotoluene (TNT), 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), and 1,3,5,7-tetranitro-1,3,5,7-tetrazoctane (HMX). PUC1 revealed highly sensitive and selective detection of PETN and Tetryl with high quenching constant values of 0.

Thiazetidin-2-ylidenes as four membered N-heterocyclic carbenes: theoretical studies and the generation of complexes with N center.

Thiazetidin-2-ylidenes have been designed as four membered N-heterocyclic carbenes (NHCs) using quantum chemical studies. These species are smaller analogs of thiazol-2-ylidenes, possess high singlet stability (57 kcal mol) and large nucleophilicity (3.4 eV).

Click chemistry inspired synthesis of andrographolide triazolyl conjugates for effective fluorescent sensing of ferric ions.

The naturally occurring compound andrographolide was used as a substrate for the synthesis of a novel terminal alkyne which on copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction with azides , and furnished a series of regioselective andrographolide triazolyl conjugates and , respectively. A free glycoconjugate was also prepared by selective deprotection of compound in good yield. All the compounds were characterized by absorbance, FT-IR, NMR, and HR-MS analyses.

Low catalyst loading enabled organocatalytic synthesis of chiral bis-heterocyclic frameworks containing pyrazole and isoxazole.

The organocatalytic asymmetric synthesis of enantiopure bis-heterocyclic molecules containing pyrazole and isoxazole under mild reaction conditions has been reported a low-catalyst loading Michael addition reaction of pyrazolyl nitroalkenes with 1,3-dicarbonyl derivatives. 4-Substituted pyrazole derivatives were obtained in 60-87% yields and with 82-97% ee. These pyrazolyl derivatives are further transformed into chiral bis-heterocyclic derivatives in up to 82% yields and up to 99% ee.

Mesoionic and N-Heterocyclic Carbenes Coordinated N Center: Experimental and Computational Analysis.

N-Heterocyclic carbenes, carbocyclic carbenes, remote N-heterocyclic carbenes and N-heterocyclic silylenes are known to form L→N coordination bonds. However, mesoionic carbenes (MICs) are not reported to form coordination bonds with cationic nitrogen. Herein, synthesis and quantum chemical studies were performed on 1,2,3-triazol-5-ylidene stabilized N center.

Oxone-DMSO Triggered Methylene Insertion and C(sp)-C(sp)-H-C(sp) Bond Formation to Access Functional Bis-Heterocycles.

Metal-free insertion of a methylene group was achieved for the construction of a new C(sp)-C(sp)-H-C(sp) bond in order to prepare novel bis-heterocyclic scaffolds. The complete mechanistic investigations included experimental study and DFT calculations, and various symmetric and unsymmetric bis-pyrazoles as well as other pyrazole-based bis-heterocyclic molecules were prepared in moderate to high yields. Further modification of the bridged methylene group in the unsymmetric pyrazoles generated a chiral center to extend the scope of this method.

One-Step Assembly of Functionalized Morpholinones and 1,4-Oxazepane-3-ones via [3 + 3]- and [3 + 4]-Annulation of Aza-Oxyallyl Cation and Amphoteric Compounds.

A new [3 + 3]- and [3 + 4]-annulation strategy involving azaoxyallyl cation and [1,]-amphoteric compounds ( = 3,4) is presented. This concise method enables easy assembly of functionalized saturated N-heterocycles, comprised of six-and seven-membered rings and is of high significance in the context of drug discovery approaches. This reaction also represents a new trapping modality of the azaoxyallyl cation with amphoteric agents of different chain lengths that consist of a heteroatom nucleophilic site and a π-electrophilic site.