Synthetic Developments of Diaryl Ditellurides Atanu Mahata, Akash Chowdhury, Habibur Rahaman, Debasish Kundu Current Organocatalysis, 2026 Diaryl ditellurides constitute an important class of organotellurium compounds with sig-nificant applications in medicinal chemistry and organic synthesis. They have proven to be power-ful organocatalysts in synthetic transformations and effective molecular fluorescent probes for the recognition of biologically active molecules. Although organotelluride compounds are less ex-plored, they have been described as promising pharmacological agents possessing anticancer, anti-inflammatory, antibacterial, antifungal, antiprotozoal, and antioxidant activities. Additionally, Te-based molecules have shown interesting applications in semiconductors, magnets, and nonlinear optical materials. The increasing interest in tellurium chemistry has been stimulated by recent de-velopments of valuable tellurium-based organocatalysts, which have proven effective in several functional group transformations under sustainable conditions. Moreover, the construction of Te–Te bonds by embedding elemental tellurium into functional moieties via telluration has become a popular research area. The synthetic methodologies are generally high yielding and exhibit notable advantages in terms of regioselectivity, broad substrate scope, excellent functional group tolerance on the aromatic ring, and high conversion ratios. A library of diaryl ditellurides bearing both elec-tron-donating and electron-withdrawing substituents has been afforded by these protocols. Despite the significant synthetic importance of diaryl ditellurides in organic synthesis, few synthetic ap-proaches have been documented in the literature to date. This review article summarizes recent developments in ditelluride synthesis under ligand- and additive-free conditions. The sustainable techniques employed involve the use of non-toxic, low-cost, commercially available reagents and environmentally benign, green solvents.
Recent Developments on Carbon-Heteroatom Coupling in Aryl and Heteroaryl Rings Under Visible Light Irradiation Debasish Kundu, Atanu Mahata, Nivedita Chatterjee Chemistryselect, 2025 Visible light photocatalysis has been appeared as a powerful sustainable tool for constructing carbon‐heteroatom bonds in recent years. Various transition metal‐based catalysts, organocatalysts, and heterogeneous semiconductors have been employed as single electron transfer agent during excitation under visible light to perform carbon‐heteroatom couplings in the aryl and heteroaryl rings. Few reaction paths were also developed recently which produced such compounds under visible light irradiation in absence of any external photocatalysts. This review summarizes the recent developments for the carbon‐heteroatom cross‐couplings in aryl and heteroaryl rings under visible light irradiation with proposed mechanistic paths under both presence and absence of external photocatalysts for the synthesis of important organic molecules in diverse fields.
Synthetic Advancements in Diaryl/Diheteroaryl/Dialkyl Diselenides Debasish Kundu Mini Reviews in Organic Chemistry, 2025 Organodiselenides bearing a Se-Se bond are the key synthons for the synthesis of a library of organoselenides with important applications in various fields of Chemistry, Biology, and Medicine. This class of molecules was found to be used as prime synthons for the synthesis of different classes of organoselenides via performing cross-coupling, C-H activation, and nucleophilic substitution under both metal-catalyzed and metal-free conditions. Apart from their broad applications in the field of organic synthesis, organodiselenides have also been found to possess high biological importance, exhibiting anti-HIV, anti-cancer, anti-tumor, and antibacterial activities. They are also found to have a potential effect against SARS-COV-2. They were also found to be efficient catalysts in different organic reactions. Therefore, the synthesis of organodiselenides is a challenging task in synthetic organic chemistry. Mainly, Se(0) and KSeCN, as selenium sources, were allowed to react with aryl/heteroaryl/alkyl halides and boronic acids to synthesize the desired diaryl/diheteroaryl/dialkyl diselenides under transition metal catalysis (Cu, Fe, Ag), organocatalysis (TMSCN), and metal-free conditions. The reactions follow different mechanistic paths, such as cross-coupling, radical mechanisms, C-H activation, and nucleophilic substitution, depending on the reaction conditions. Apart from conventional heating, solvent-free mechanical ball-milling was also applied for their synthesis. Diaryl diselenides with both electron-donating and electronwithdrawing functional groups were synthesized in good to excellent yields using these protocols. This review summarizes all published protocols for the synthesis of organodiselenides, including detailed mechanisms, over the last 15 years, and outlines future scopes in this important field of organic synthesis.
Sustainable Tools for C-C and C-heteroatom Cross-coupling from Aryl Diazonium Salts Atanu Mahata, Debasish Kundu Current Green Chemistry, 2025 Aromatic and heteroatomic diazonium salts constitute a significant class of very reactive electrophiles. In recent times, reactions of diazonium compounds under visible-light photocatalysis, microwave irradiation, and ball-milling strategies have been at the forefront of organic synthesis. The anions like tetrafluoroborate, mesylate, tosylate, disulfonamide, except for chloride and carboxylate, tethered with the aromatic rings of diazo frameworks, have rendered exceptional stability. The synthetic methodologies are highly advantageous in terms of regioselectivity of yields, broad substrate scope, excellent functional group tolerance, and high conversion ratio. These sustainable approaches not only reduce waste production, but also facilitate a ubiquitous eco-friendly protocol which enables strategies, transformations, and syntheses that are typically unachievable in solution. This current review article summarizes the recent developments of aryl diazonium compounds in the field of organic synthesis under ligand- and additive-less conditions. The sustainable techniques employed herein involve the use of non-toxic, low-cost, commercial-grade reagents, environmentally benign and greener solvents.
Recent Advances in Fluorometric Detection of Carcinogenic Heavy Metal Ions Using Fluorogenic Chemosensors: An Overview Atanu Mahata, Agnishwar Girigoswami, Debasish Kundu Current Organic Chemistry, 2025 In recent years, a significant focus has been directed toward fluorogenic chemosensors for the optical detection of heavy metal ions due to their detrimental effects on both the environment and human health. Methods combining fluorometry and colorimetry have been widely utilized for sensing heavy metal ions because they are straightforward, lucrative, easy to use, and enable rapid on-site analysis. As a result, numerous research groups have dedicated extensive efforts to developing versatile fluorometric and colorimetric sensors for heavy metals. The development of innovative, highly selective, and sensitive chromogenic fluorosensors, along with their detection capabilities, remains a captivating area within supramolecular chemistry. This review outlines key aspects of the detection process, including spectroscopic changes, selectivity, sensitivity, visible colour shifts, and potential in vivo recognition of heavy metal ions. It also emphasizes recent progress over the past decade in the fluorometric and colorimetric detection of heavy metal cations, such as Hg²⁷, Cd²⁷, As3+/As5+, and Pb2+, using chromogenic and fluorogenic chemical receptors.
Metal-catalyzed Synthesis of Phenanthrene and its Derivatives: A Core Structure of Various Natural Products Khokan Samanta, Sachinath Bera, Mitali Dewan, Basudev Mandal, Shubhankar Samanta, Debasish Kundu, Rathin Jana Current Organic Chemistry, 2025 Phenanthrenes and their dihydro derivatives have attracted considerable attention due to their widespread occurrence in natural products and pharmaceuticals with biological activities, which have led to their application in the treatment of microbial or viral infections, allergies, cancer, and malaria. Nowadays, the transitional metal-catalysed reactions are useful approaches for the synthetic transformation of organic compounds due to high yield and step economy. This approach, owing to the use of non-pre functionalized substrates, minimizes the chemical wastes. Among the various synthetic strategies, metalcatalyzed C-H bond activation and also Heck reactions have recently drawn a lot of interest in synthesizing decorated π-conjugated polycyclic aromatic hydrocarbon. In this review, we have focused on recent progress along with previous strategies to synthesize various phenanthrene and its derivatives by the use of metal-catalyzed reactions and also discussed the mechanistic details of the reaction.
Carbon-Chalcogenide Cross-Coupling Reactions in Water Atanu Mahata, Totan Roy, Animesh Mondal, Debasish Kundu Current Green Chemistry, 2024 : Over the past two decades, researchers have witnessed the synthesis of diaryl sulfides and diaryl selenides via transition metals-mediated carbon-heteroatom cross-coupling reactions in the presence of various organic and inorganic solvents. The use of water as a clean and environmentally friendly solvent in cross-coupling chemistry of C-S/Se bond formations has attracted profound interest owing to its availability, non-toxicity, low cost and renewability. The most commonly used solvents have been recognized as being of environmental concern, but the use of green and eco-friendly solvents like water is frequently considered with respect to the recovery of catalysts, isolation of products, and recycling. The fundamental interactions between the water and the transition metal catalysts or ligands are viewed from mechanistic aspects, which mostly favours the rational selection of high-performance and safe solvents. In this article, the authors intended to focus extensively on the critical role of water in various transition metals mediated C-S/Se cross-coupling methodologies.
Synthesis of Unsymmetrical Diaryl Tellurides Under Mechanical Ball Milling in Room Temperature Anup Roy, Subir Panja, Pradipta Kumar Basu, Debasish Kundu Current Organic Chemistry, 2024 An efficient transition metal catalyst-free protocol for the synthesis of unsymmetrical diaryl tellurides has been developed by the reaction of diaryl tellurides and aryl diazonium tetrafluoroborates under mechanical ball milling in the absence of any solvent and base under room temperature. InBr (Indium Bromide) plays an important role in generating the organotelluride nucleophile via the Te-Te bond cleavage of ditelluride. A library of diaryl tellurides bearing both electron-donating and withdrawing groups in the aromatic ring has been synthesized in good to excellent yields by this protocol. Despite very high synthetic importance of diaryl tellurides in the field of organic synthesis, very few protocols have been reported to date for their synthesis. The reactions were also performed on a gram scale without any considerable change in the yields, which surely broadened the applicability of this methodology in the industrial field.
Synthesis of Polynuclear Aromatic Hydrocarbons by Palladium-catalyzed C-H Bond Functionalization Mitali Dewan, Sachinath Bera, Shubhankar Samanta, Debasish Kundu, Rathin Jana Current Organic Chemistry, 2024 : Nowadays palladium-catalyzed C–H bond activation is a useful approach for the synthetic transformation of organic compounds due to step economy, the use of non-prefunctionalized substrates and reduced chemical wastes. Among the various synthetic strategies, palladium catalyzed intra and inter-molecular C–H bond activation has recently drawn a lot of interest to synthesize the decorated π-conjugated polycyclic aromatic hydrocarbon. In this review, we have focused on recent progress along with previous strategies to synthesize various polynuclear aromatic hydrocarbons (PAHs) by the use of Pd-catalyzed C–H bond activation. We have also discussed the mechanistic details of the reaction intra and inter-molecular C–H bond activation.
Transition Metals Catalyzed Direct C-H Chalcogenation of Arenes and Heteroarenes Atanu Mahata, Madhusudan Garain, Totan Roy, Dilip Gorai, Debasish Kundu Current Organic Synthesis, 2024 Transition metals catalyzed C-H bond activation reactions have appeared as an emerg-ing field to introduce different functional groups in the inactivated saturated and unsaturated C-H bonds. C-S and C-Se bond constructions in aromatic scaffolds are very interesting due to the im-portant applications of organochalcogen reagents in pharmaceutical chemistry and the material world. The introduction of sulphur or selenium moiety to an inert C-H functionality of an arene under transition metal catalysis has become one of the prime challenges and targets in recent years. In this perspective, various transition metals such as Cu, Ni, Co, Pd, Rh, Ru etc. have been extensively studied. Aromatic arenes owning bearing suitable directing groups appeared as the most promising coupling partners to selectively synthesize differently substituted aryl sulfones and aryl sulfides/selenides. The synthetic strategies were highly convenient owing to the regiose-lectivity of products, broad substrate scope, mild reaction conditions and excellent functional group tolerance. The current review article comprehensively summarizes the extent of C-S/Se bond formation via transition metal-catalyzed C-H bond activation with the assistance of directing groups to govern the site selectivity.
Ionic liquid as base and phase transfer agent: A green protocol for the synthesis of diaryl sulphides in water Journal of the Indian Chemical Society, 2013
