Article
Chemistry, Organic
Merlin Kleoff, Lisa Boeser, Linda Baranyi, Philipp Heretsch
Summary: A metal-free synthesis method for benzotriazoles in flow using azides and in situ generated arynes is reported. The modular access to benzotriazoles is provided by employing different substitution patterns of the azide and aryne coupling partners. The safety profile of the process is improved by minimizing thermal strain of hazardous azides and accumulation of reactive intermediates through short reaction times in flow. The scalability of the reaction is also demonstrated.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Valeriia Hutskalova, Alessandro Prescimone, Christof Sparr
Summary: The study of new synthetic routes for positively charged N-heterocycles is crucial for the advancement of medicinal chemistry, functional materials, catalysis, and other applications. By utilizing phenanthryne as the aryne component, a novel synthetic methodology was developed to form a helical tetrabenzophenanthridinium derivative, which exhibited susceptibility to photoinduced cyclodehydrogenation. The photophysical and electrochemical properties of the resulting compound were also determined.
HELVETICA CHIMICA ACTA
(2021)
Article
Chemistry, Multidisciplinary
Maximilian Scheruebl, Constantin G. Daniliuc, Armido Studer
Summary: The article introduces the application of arynes as radical acceptors, showing how the stable radical TEMPO can react with different ortho-substituted benzynes to generate aryl radicals for subsequent cyclizations, eventually being trapped by TEMPO. This method provides a novel approach for the convenient synthesis of various dihydrobenzofurans, oxindoles, and sultones.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Hao Yuan, Dong-Liu Lu, Cui Liang, Dong-Liang Mo
Summary: Various spirooxindole-benzo[d]oxazoles and dihydrobenzofurans were successfully synthesized via transition metal-free [3 + 2] cycloaddition and selective rearrangement. The substituent on the N-vinyl group of the nitrone was found to control the [1,3]- or [3,3]-rearrangement of the cycloadduct due to steric effects. This method demonstrates broad substrate scope, good functional group tolerance, controllable rearrangement, and diverse oxindole scaffolds.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Yu Zhang, Yanchuan Li, Shao-Fei Ni, Jin-Peng Li, Dingding Xia, Xinyu Han, Jingchuan Lin, Jinxin Wang, Shoubhik Das, Wei-Dong Zhang
Summary: Visible-light-induced [3+2] cycloadditions of donor/donor diazo precursors with alkenes to afford pyrazoles and (spiro)pyrazolines have been reported. Mechanistic and DFT studies suggested the non-covalent interactions promote the reaction.
Article
Chemistry, Multidisciplinary
Yu Zhang, Yanchuan Li, Shao-Fei Ni, Jin-Peng Li, Dingding Xia, Xinyu Han, Jingchuan Lin, Jinxin Wang, Shoubhik Das, Wei-Dong Zhang
Summary: Visible-light-induced [3+2] cycloadditions of donor/donor diazo precursors with alkenes to afford pyrazoles and (spiro)pyrazolines have been reported. Mechanistic and DFT studies suggested the formation of non-covalent interactions promote the reaction.
Article
Chemistry, Organic
Bubul Das, Nikita Chakraborty, Kamal Krishna Rajbongshi, Bhisma K. Patel
Summary: This article reviews different methods and approaches for the synthesis of N/O/S-heterocycles using styrene as an annulating partner in the past five years. These heterocycles are widely present in the core structure of various natural products, pharmaceuticals, and agrochemicals.
Review
Chemistry, Applied
Ahmad Saifuddin Mohamad Arshad, Mohd Nizam Mordi
Summary: Carbolines are a prominent class of tricyclic alkaloids found in natural products, and there are four different regioisomers known. Synthetic methods have been established for the construction of carboline frameworks, both requiring customized approaches for each regioisomer and unified approaches capable of generating multiple regioisomers. This review summarizes the construction of isomeric carbolines based on unified synthetic approaches.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Review
Chemistry, Applied
Seoung-Mi Choi, Ju Hyun Kim
Summary: This review summarizes the progress made in the synthesis of 2H-pyrroles since 2000, including methods such as dearomatization of 1H-pyrrole, oxidation of pyrrolines or pyrrolidines, ring construction via catalytic cycloaddition, and rearrangement of 3H-pyrroles.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Review
Chemistry, Organic
Rida Noor, Ameer Fawad Zahoor, Syed Ali Raza Naqvi, Atta ul Haq, Rabia Akhtar
Summary: This review examines the synthetic routes attempted in the past two decades for forming large size carbocycles and heterocycles using ring expansion reactions, including lactams, boracycles, benzocycloheptenones, azaborinine, and azepine derivatives. Various rearrangement and cycloaddition reactions have been discussed.
SYNTHETIC COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Vladimir V. Voronin, Maria S. Ledovskaya, Konstantin S. Rodygin, Valentine P. Ananikov
Summary: This work presents a universal synthetic approach for the synthesis of D-2-labeled nitrogen heterocycles through cycloaddition reactions using in situ generated dideuteroacetylene. By using 1,4-dioxane as a solvent, the method allowed for high levels of deuteration up to 99%. It was demonstrated to be suitable for the synthesis of various D-2-labeled heterocycles such as triazoles, isoxazoles, pyrazoles, and pyridazines.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Biochemistry & Molecular Biology
Yaqi Zhao, Zhengqi Chai, Qingrui Zeng, Wen-Xiong Zhang
Summary: Nowadays, the click reaction of azides with alkynes has rapidly evolved as an efficient method for synthesizing 1,2,3-triazoles, an important class of N-containing heterocycles. While the 1,4-selective click reaction is well-established, the corresponding 1,5-selective reaction remains less explored, lacking a systematic review. This timely review summarizes the discovery and development of 1,5-selective click reactions of azides with alkynes for synthesizing 1,5-substituted 1,2,3-triazoles, including three types of reactions based on critical reactive intermediates and related mechanistic studies.
Review
Chemistry, Organic
Christian Dank, Laura Ielo
Summary: This review article discusses the recent progress in the biological and chemical evolution of aziridine derivatives, with a focus on the synthesis of aziridines and their transformation reactions. These compounds have shown great potential from both synthetic and pharmacological perspectives and have attracted significant attention due to their promising biological activities.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Rui Chang, Yubing Pang, Juntao Ye
Summary: This study reports a photoinduced approach for hydroarylation of unactivated olefins using 4-hydroxycoumarins as the arylating reagent. The key to the success of this reaction is the conversion of nucleophilic 4-hydroxycoumarins into electrophilic carbon radicals through photocatalytic arene oxidation. This method not only overcomes the polarity-mismatch issue encountered under ionic conditions but also allows for a broad substrate scope and inhibits side reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Tsukasa Tawatari, Ritsuki Kato, Riku Kudo, Kiyosei Takasu, Hiroshi Takikawa
Summary: In this study, we report on the intramolecular (3+2) cycloaddition reactions between ynamides and benzyne. These reactions involve the formation of two bonds and are facilitated by using benzyne precursors containing a chlorosilyl group. The intermediate indolium ylide in these reactions exhibits both nucleophilic and electrophilic properties at its C2 atom.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Suman Pradhan, Sourav Roy, Basudev Sahoo, Indranil Chatterjee
Summary: CO2 is being efficiently converted into value-added products through catalytic techniques, with visible-light photocatalysis playing a significant role in this process. The combination of CO2 with light energy has shown promising results, particularly in the past three years.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Review
Chemistry, Organic
Anup Biswas, Avisek Ghosh, Rajat Shankhdhar, Indranil Chatterjee
Summary: Chiral analogues of squaramides have proved to be efficient asymmetric catalysts in the synthesis of acyclic and cyclic chiral molecules. By utilizing several bifunctional squaramides as catalysts, a wide range of cyclic molecules bearing multiple functionalities and stereocenters have been successfully synthesized.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Suman Pradhan, Vishali Sharma, Indranil Chatterjee
Summary: Using HFIP solvent and rare metal-free nucleophilic nitrosoarene catalyst, this study successfully converts arylmethyl halides to aromatic carbonyls with good chemoselectivity under mild reaction conditions. The activation of arylmethyl halides by HFIP and the autoxidation of in situ generated hydroxylamine to nitrosoarene in the presence of atmospheric O-2 are crucial for the success of this protocol.
Article
Chemistry, Organic
Sourav Roy, Gourav Kumar, Indranil Chatterjee
Summary: In this study, nitrosoarene was utilized as a mild oxygen source to oxidize an in situ generated carbene intermediate, enabling UV-light-mediated ketenes to react with nitrosoarenes and deliver oxazetidine derivatives. These simple processes highlight a transition-metal-free and catalyst-free protocol for obtaining structurally diverse alpha-ketoesters or oxazetidines.
Article
Chemistry, Multidisciplinary
Soumen Ghosh, Zheng-Wang Qu, Suman Pradhan, Avisek Ghosh, Stefan Grimme, Indranil Chatterjee
Summary: This study presents a novel visible light photoredox catalytic method for the selective cleavage of a single strong C-F bond in trifluoromethyl ketones. The reaction shows excellent chemoselectivity and functional group tolerance under mild conditions, and high-level DFT calculations are used to elucidate the mechanism.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Gautam Kumar, Zheng-Wang Qu, Stefan Grimme, Indranil Chatterjee
Summary: Catalytic hydroarylation reactions of conjugated dienes using tris(pentafluorophenyl)borane as a Lewis acid catalyst show a broad substrate scope for highly regioselective functionalization of sterically hindered aniline derivatives. Experimental and theoretical studies reveal the crucial role of residual water and B(C6F5)(3) complex in the reaction mechanism.
Review
Chemistry, Organic
Sourav Roy, Hrishikesh Paul, Indranil Chatterjee
Summary: Primary and secondary amines have been widely used for valuable transformations in chemistry, and their combination with visible-light photoredox catalysis has become a crucial synthetic pillar. This dual catalytic system showcases a new green and sustainable synthetic approach with high efficiency in accessing molecular complexity.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Suman Pradhan, Sampurna Das, Gautam Kumar, Indranil Chatterjee
Summary: The unique property of hexafluoroisopropanol (HFIP) enables the regioselective hydroamination of 1,3-dienes with nitrogen heterocycles in a Markovnikov manner in the presence of catalytic Bronsted acid. This transition-metal-free intermolecular hydroamination protocol is achieved under mild reaction conditions. The aggregation by HFIP and Brensted acid helps to activate the terminal double bond regioselectively, leading to protonation of the diene and subsequent C-N bond formation with heterocyclic amines.
Article
Chemistry, Applied
Gautam Kumar, Debkanta Bhattacharya, Indranil Chatterjee
Summary: A transition-metal-free aminocyanation of aryl alkynes has been achieved using Lewis acids, showing non-toxic cyanide source, good substrate scope, and potentially valuable products.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Review
Chemistry, Organic
Biprajit Paul, Hrishikesh Paul, Indranil Chatterjee
Summary: This review highlights the development of photoredox-mediated desulfonylation reactions since 2000, which have emerged as a powerful strategy for C-C and C-X bond formation. The mild reaction conditions, wide functional group tolerance, and excellent synthetic efficacy make these reactions highly attractive in synthetic organic, bio, and material chemistry.
SYNTHESIS-STUTTGART
(2022)
Proceedings Paper
Telecommunications
Jitendra Singh, Indranil Chatterjee, Suraj Srivastava, Aditya K. Jagannatham
Summary: In this paper, a hybrid transceiver architecture along with optimal power allocation is proposed for a downlink millimeter wave multi-input multi-output cognitive radio system. The non-convex objective and constraints are simplified by decoupling the hybrid precoder and combiner designs. Simulation results show significant improvements compared to existing approaches.
2022 NATIONAL CONFERENCE ON COMMUNICATIONS (NCC)
(2022)
Article
Chemistry, Multidisciplinary
Sandeep Patel, Biprajit Paul, Hrishikesh Paul, Rajat Shankhdhar, Indranil Chatterjee
Summary: A method for generating alkyl radicals using visible-light photoredox catalysis is described. The procedure involves the single-electron transfer of sulfones, leading to the formation of a diverse collection of 1 degrees, 2 degrees, and 3 degrees alkyl radicals. These alkyl radicals can be utilized for forging C-C bonds. Mechanistic studies were conducted to provide insights into the process.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Soumen Ghosh, Sandeep Patel, Indranil Chatterjee
Summary: In the past few decades, the inert C-H bond functionalization reactions have emerged as a powerful technique for synthesizing complex molecules, but the distant and selective activation of unreactive C-H bonds remains a critical challenge. Recent advancements in transition metal catalytic transformations utilizing the chain-walking process have shown promising potential for overcoming this challenge and further developing this field.
CHEMICAL COMMUNICATIONS
(2021)
Review
Chemistry, Organic
Gautam Kumar, Sourav Roy, Indranil Chatterjee
Summary: Tris(pentafluorophenyl)borane (BCF) has gained significant attention in the synthetic chemistry community as a potential Lewis acid catalyst due to its thermal stability and commercial availability. Recent research has focused on exploring BCF's role in metal-free catalysis, with many new catalytic reactivities under investigation. The review mainly categorizes different types of organic transformations mediated through BCF catalysis for the formation of C-C and C-heteroatom bonds.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Sourav Roy, Suman Pradhan, Krishan Kumar, Indranil Chatterjee
ORGANIC CHEMISTRY FRONTIERS
(2020)
