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Cascade approach to synthesize BIMs and analogues in different nucleophilic conditions

2024, Kailas Arjun Chavan, Prakash N. Chavan, Erande, Rohan Diliprao, Kumar, Akhilesh

We report here a cascade synthetic approach to prepare 3,3′-bis(indolyl)methanes (BIMs) and analogues from single reactant 1H-indole-3-carbaldehydes under the reductive condition using NaBH4. Uniformly, in another strategy, 1H-indole-3-carbaldehydes produced BIMs as a cascade product under Grignard reaction conditions. This is the first application of organometallic and reductive nucleophilic condition, where indole-3-carbaldehydes underwent NaBH4 reduction/ methyl Grignard addition to form 1°/2° alcohol followed by elimination and subsequent addition of another molecule of indole aldehyde provided symmetric BIMs as unambiguous cascade products (22 analogues) in good to excellent yields.

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Vanadium (IV)oxo catalyzed One-Pot transformation of cinnamate to aromatic ester and its mechanistic aspects

2024, Ghanshyam Mali, Indresh Verma, Himanshu Arora, Amit Rajput, Manoj V. Mane, Akhilesh Kumar, Erande, Rohan Diliprao

Metal-catalyzed oxidative cleavage of unsaturated carbon–carbon bond is among the utmost valuable chemical transformations in synthetic organic chemistry. However, the direct transformation of cinnamate to benzoate remains an unsolved task in the series. Herein, we have developed an unprecedented one-pot strategy for the direct transformation of cinnamate esters to aromatic ester using V-catalyst [(L2)VIVO](ClO4) and green oxidant H2O2 in alcohol-reflux condition. The reaction on cinnamate proceeded via C[dbnd]C bond breaking to generate aldehyde intermediate, followed by oxidative esterification to yield two carbon less aromatic esters in 52–95% yields. Further, experimental and DFT studies confirmed the mechanism and in-situ aldehyde formation which consequently supported to the developed protocol.

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PPh3-catalyzed chemoselective reduction of aldehydes to alcohols

2024, Amar Nath Singh Chauhan, Erande, Rohan Diliprao

Reduction of aldehydes to alcohols is a fundamental organic transformation, typically achieved through metal-catalyzed reductions or by the use of hydride-based reagents. However, these conventional methods often go through harsh conditions with expensive catalysts and additional reductants, limiting their broader applications. In this study, for the first time we introduce an efficient, metal-free reduction strategy using triphenylphosphine (PPh3) and KOtBu in MeOH. This method exhibits broad functional group tolerance, mild environment and selectivity in reducing aldehydes even in the presence of other reactive functionalities (NO2, CN, ketone, etc.). Key features highlight this novel approach with practicality, scalability to gram scales and excellent yields for the reduction of varied aldehydes to alcohols (30 examples; 65–95 % Yields).

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Rapid Access to Nitriles and Esters from Aldehydes via NH₂OH Catalyzed Ultrasonication Approach

2025-06, Amar Nath Singh Chauhan, Parth Kumar Singh, Erande, Rohan Diliprao

Nitriles, oximes, and esters are crucial intermediates in organic synthesis, yet obtaining them from renewable feedstocks using simple, eco-friendly, and efficient systems remains challenging. We described a convenient, scalable and transition-metal free method for the direct oxidative conversion of aldehydes to nitriles and esters. This approach uses commercially available NH₂OH·HCl as a safe, non-toxic nitrogen source, thereby eliminating the need for external cyanide, and employs ethanol as a green solvent in combination with ultrasonication. The complete avoidance of toxic cyanide salts not only enhances the safety profile of the method but also aligns with green chemistry principles, making it highly attractive for sustainable synthesis. The dual advantage of developed strategy enables the selective formation of cyano and ester functionalities from the aldehyde via oxime intermediates (>70 examples; 55–95% yield). Moreover, the method demonstrates excellent efficiency on a larger scale, emphasizing its strong potential in organic synthesis. © 2025 Wiley-VCH GmbH.

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A Catecholaldimine-Based NiII-Complex as an Effective Catalyst for the Direct Conversion of Alcohols to trans-Cinnamonitriles and Aldehydes

2023-06-02, Sharma, Vivek, Chavan, Kailas Arjun, Mali, Ghanshyam, Sarkar, Dipanjana, Lama, Prem, Majumder, Moumita, Erande, Rohan Diliprao, Metre, Ramesh

A nickel(II) complex [Ni(HL)2] 1 was synthesized by treatment of a new catecholaldimine-based ligand with NiCl2·6H2O in methanol at room temperature. Complex 1 showed excellent catalytic activity where aromatic and heterocyclic alcohols were rapidly converted into trans-cinnamonitrile in a one-pot manner via oxidative olefination in the presence of KOH. The potential of the disclosed catalyst and the results obtained for the direct conversion of alcohols to two different functionalities (trans-cinnamonitrile and aldehydes) are well supported by DFT studies.

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Selective Functionalization of Indole: Synthesis of Bioinspired 2,2′‐thiobisindoles, 3‐substituted Oxindoles, and 1‐(chloromethyl) Indoline‐2‐dione in One‐pot manner

2024, Supriya Sharma, Akhilesh Kumar, Erande, Rohan Diliprao

Indolyl thioethers and indolin-2-one motifs are extremely common in pharmaceuticals and organic materials, therefore developing a method to create these scaffolds is considered to be a vital endeavour in the chemical sciences. Here we have reported a unified strategy developed by the fine-tuning of catalyst-solvent combination [SOCl2 /AlCl3 in CHCl3 and SOCl2/DMSO (1 : 1) in CHCl3 at 25 °C] towards selective functionalization of Indole to synthesize 2,2′-thiobisindoles and 3-chloro-3-alkyl substituted oxindoles selectively in one-pot manner with good to satisfactory yield (52-86 %; 26 Examples). In application, reactions of 3-subsituted indole and isatin derivatives produced the 1-(chloromethyl) indoline-2,3-diones by just changing the reaction condition (60 °C), which shows the synthetic utility of the developed method.

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Synthesis of indol-3-yl-benzofurans and carbazoles via Cu(OTf)2-catalyzed [3 + 2] and [4 + 2] cycloaddition

2024, Amar Nath Singh Chauhan, Vikrant Vini, Akhilesh Kumar, Erande, Rohan Diliprao

An efficient Cu(OTf)2-catalyzed [3 + 2] cycloaddition of indole-3-acrylate with p-benzoquinone has been developed to construct two distinct indole-tethered benzofuran scaffolds, offering the first-ever selective access to these scaffolds. Moreover, the [4 + 2] cycloaddition reaction of indole-3-acrylate with vinyl ketone derivatives was used to synthesize carbazoles in a one-pot manner. The disclosed strategies provided a series of selective transformations under low-catalyst loading, with a broad substrate scope featuring diverse applicability and practical simplicity of the developed protocol with easily available substrates.

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Recent Advances in Organometallic Reagents and Catalysts: A Concise Strategy to Synthesize Cannabinoid Natural Products

2025-09, Amar Nath Singh Chauhan, Supriya Sharma, Omkar A. Sonawane, Erande, Rohan Diliprao

Cannabis sativa L., a genus of the Cannabis family, is an exclusive source of C21 terpenophenolic cannabinoids and an important class of bioactive compounds known for their health effects. Moreover, cannabinoids are found to exhibit remarkable properties in treating various ailments like rheumatism, asthma, glaucoma, fatigue, insomnia, nausea, and epilepsy. This review shares a broad interest in examining the detailed chemistry of significant cannabinoids—THC (tetrahydrocannabinol) and CBD (cannabidiol)—with respect to their synthetic advances using organometallic reagents and catalysis. The studies highlighted herein manifest the compilation of a range of metal reagents such as Au, Ru, Pd, Mo, Ir, Rh, Re, Cu, Ni, and Zn for generating cannabinoid natural products from simple building blocks, with emphasis on breakthroughs and potential for their constructive synthesis. © 2025 Elsevier B.V., All rights reserved.

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One-Pot Green Synthesis and Biological Evaluation of Dimedone-Coupled 2,3-Dihydrofuran Derivatives to Divulge Their Inhibition Potential against Staphylococcal Thioredoxin Reductase Enzyme

2024, Manjari Shukla, Ghanshyam Mali, Supriya Sharma, Sushobhan Maji, Vinay Kumar Yadav, Bhattacharyya, Sudipta, Mishra, Amit Kumar, Erande, Rohan Diliprao

New therapeutic leads are in global demand against multiple drug-resistant Staphylococcus aureus, as presently there is no drug of choice left to treat this pathogen. In the present work, we have designed, synthesized, and in vitro validated dimedone-coupled 2,3-dihydrofuran (DDHF)-based inhibitor scaffolds against Staphylococcal thioredoxin reductase (SaTR), a pivotal drug target enzyme of Gram-positive pathogens. Accordingly, a green multicomponent method that is both efficient and one pot has been optimized to synthesize DDHF derivatives. The synthesized DDHF derivatives were found to inhibit a purified SaTR enzyme. The best inhibitor derivative, DDHF20, inhibits SaTR as a competitive inhibitor for the NADPH binding site at low micromolar concentrations. DDHF20-capped silver nanoparticles are synthesized and characterized, and their bactericidal property has been checked in vitro. Furthermore, detailed in silico-based structure-guided functional studies have been carried out to uncover the plausible mode of action of DDHF20 as a potential anti-Staphylococcal therapeutic lead.