Article
Biochemistry & Molecular Biology
Arisa Chiba, Ryoko Tanaka, Mayuno Hotta, Kayo Nakamura, Kosho Makino, Hidetsugu Tabata, Tetsuta Oshitari, Hideaki Natsugari, Hideyo Takahashi
Summary: The stereochemical properties of N-acyl-5H-dibenzo[b,d]azepin-7(6H)-ones that inhibit potassium channels in T cells were studied by freezing their conformational change due to 4-methyl substitution. These acylated compounds exist as pairs of enantiomers and can be separated at room temperature. An alternative method for their synthesis involves the intramolecular Friedel-Crafts cyclization of N-benzyloxycarbonylated biaryl amino acids.
Article
Chemistry, Organic
Takuya Namba, Mayuno Hotta, Hidetsugu Tabata, Kosho Makino, Tetsuta Oshitari, Hideaki Natsugari, Hideyo Takahashi
Summary: The stereochemistry of N-acyl/N-sulfonyl 5H-dibenzo[b,d]azepin-7(6H)-ones was studied with a methyl group at the C-4 position freezing the conformation. Enantiomers (a(1)R, a(2)R) and (a(1)S, a(2)S) were found to exist as a pair, and amide derivatives were shown to be in equilibrium with the E/Z-amide forms. The electron-withdrawing property of the amino-protective group was highlighted as crucial for successful seven-membered cyclization.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Zhi Tang, Zhiqing Wang, Zhihong Peng, Qinghua Yang, Shuang-Feng Yin, Renhua Qiu
Summary: An efficient protocol for synthesizing indolin-2-ones from benzofuranones and aryl amines using iodine as a mediator has been developed. A diverse range of benzofuranones and aryl amines undergo cross-dehydrogenative coupling and amidation to produce products in yields ranging from 24-93%. The reaction can be easily scaled-up to produce indolin-2-ones in a gram scale, with further chemical manipulation enabling useful transformations of the phenol ring.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Han-Han Kong, Long Zhao, Hong-Ling Pan, Ming-Wu Ding
Summary: A new one-pot method has been developed for the preparation of dibenzo[b,e]azepin-6(11H)-one by combining a sequential Ugi-4CR with a sulfur ylide-mediated rearrangement reaction. Polysubstituted dibenzo[b,e]azepin-6(11H)-ones were synthesized in 69-84% yield using readily available sulfonium salts, 2-aminophenyl ketones, aldehydes, and isocyanides in the presence of DBU.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Huaanzi Hu, Yan Peng, Ting Yu, Sidi Cheng, Shuang Luo, Qiang Zhu
Summary: Enantioselective 7-exo-trig cyclocarbopalladation-initiated carbonylation cascade reactions have been successfully achieved, yielding seven-membered dibenzo[b,d]azepin-6-ones with a thermodynamically controlled stereogenic axis and excellent diastereo- and enantioselectivities. The calculated energy difference between diastereoisomers is approximately 2.8 kcal/mol, explaining the observed high diastereoselectivity.
Article
Chemistry, Organic
Sergey Gritsevich, Alexander Sapegin, Mikhail Krasavin
Summary: In this study, 5,11-Dihydro-6H-dibenzo[b,e]azepin-6-ones were successfully expanded into 5,7,8,14-tetrahydrodibenzo[e,h][1,4]diazecin-9(6H)-ones using the hydrated imidazoline ring expansion (HIRE) method.
TETRAHEDRON LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Yani Luo, Tian Tian, Yasushi Nishihara, Leiyang Lv, Zhiping Li
Summary: A simple and efficient strategy for iron-catalysed cascade radical cyclization was developed to synthesize a variety of compounds using germanium hydrides as radical precursors. The new method allowed for the selective arylgermylation of alkenes over the prevalent hydrogermylation reaction.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Hemanta Hazarika, Kangkana Chutia, Babulal Das, Pranjal Gogoi
Summary: An aryne-based synthetic protocol has been developed for the synthesis of 3-substituted-3-hydroxy-indolin-2-ones, yielding a wide variety of products in good yields. One of the synthesized compounds has been confirmed by single crystal XRD analysis. Treating the synthesized derivatives with an inorganic base at high temperature leads to an interesting o-arylated product of 1,3-cyclohexandione.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Constanze Keck, Jennifer Hahn, Divanshu Gupta, Holger F. Bettinger
Summary: This study reveals a highly acidic boron-nitrogen compound that can interact with silicon-containing compounds and activate their silicon bonds, providing insights into the insertion reaction mechanism.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Constanze Keck, Jennifer Hahn, Divanshu Gupta, Holger F. Bettinger
Summary: The research demonstrates that the boron-nitrogen analogue of ortho-benzyne is a reactive intermediate capable of interacting with silicon-containing single bonds and even activating and inserting into very strong Si-F bonds.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Applied
Jingzhi Sui, Yun He, Tao Wang, Yong Liang, Zunting Zhang
Summary: The synthesis of three types of quinoline compounds, including trans-4a,12b-dihydrodibenzo[fh]quinolin-2(1H)-ones (2), dibenzo[f,h]quinolin-2(1H)-ones (3) and 3,4-dihydrodibenzo[f,h]quinolin-2(1H)-ones (4), was achieved through photo-induced annulation of 6-([1,1'-biphenyl]-2-yl)pyridine-2(1H)-ones (1) under 313 nm UV light. The highest yield reached 95%.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Ruo-Pu Li, Zheng-Lin Wang, Yun-Hao Zhang, Zhi-Yu Tan, Da-Zhen Xu
Summary: In this study, we have described a method for the construction of all-carbon quaternary centers via cross-dehydrogenative coupling reaction. The method, catalyzed by I-2, operates under metal-free and peroxide-free conditions, resulting in the formation of 3,3-disubstituted oxindoles through two C-C bond formations from secondary C(sp(3))-Hs.
Article
Chemistry, Organic
Junrong Chen, Muhammad Suleman, Ping Lu, Yanguang Wang
Summary: A catalyst-controlled selective synthesis of benzofuro[2,3-c]isoquinolines and 5,6-dihydro-7H-benzo[c]benzofuro[2,3-e]azepin-7-ones from salicylaldehydes and 4-diazoisoquinolin-3-ones has been developed. The Co(III)-catalyzed reactions furnished benzofuro[2,3-c]isoquinolines as major products, while the Rh(III)-catalyzed reactions afforded 5,6-dihydro-7H-benzo[c]benzofuro[2,3-e]azepin-7-ones as major products.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Yang Kang, Yun He, Jingzhi Sui, Tao Wang, Yong Liang, Zunting Zhang
Summary: An efficient and environmentally friendly method for the synthesis of polycyclic-fused isoindolinones has been reported, involving annulation of 3,4-diphenyl-3-pyrrolin-2-ones under irradiation with a 500 W mercury lamp in EtOH under an argon atmosphere. The method tolerates various electron-donating and electron-withdrawing groups, and selected annulation products can be further oxidized into dibenzo[e,g]isoindole-1,3(2H)-diones in the presence of CH3ONa at room temperature.
Article
Oncology
Baijayantimala Swain, Priti Singh, Andrea Angeli, Santosh Kumar Sahoo, Venkata Madhavi Yaddanapudi, Claudiu T. Supuran, Mohammed Arifuddin
Summary: A high yielding green protocol has been developed for the synthesis of 3,3-di(indolyl)indolin-2-ones and their carbonic anhydrase inhibitory activity was screened. The synthesized compounds showed selective inhibition towards hCA II at low concentrations. The catalyst used in the reaction exhibited excellent performance and recyclability.
ANTI-CANCER AGENTS IN MEDICINAL CHEMISTRY
(2022)
Article
Chemistry, Organic
Manas Jyoti Sarma, Sana Jindani, Bishwajit Ganguly, Srihari Pabbaraja, Goverdhan Mehta
Summary: An efficient protocol for the synthesis of orthogonally strap diynones through one pot transition-metal-free reaction has been developed. Insights into the regioselective tandem Michael-anti-Michael processes have been gleaned through DFT calculations.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
P. Srihari, Y. Bharath Kumar, B. Suresh
ORGANIC PREPARATIONS AND PROCEDURES INTERNATIONAL
(2022)
Article
Chemistry, Organic
Ravi Gurram, Srihari Pabbaraja
Summary: A stereoselective synthetic strategy for (+)-paecilomycin F was developed using readily available 2,4,6-trihydroxy benzoic acid and chiral R(+)-propylene oxide. The synthesis involved key reactions such as regioselective Grignard reaction, Wittig reaction, Sharpless asymmetric dihydroxylation, Barbier-type allylation, Stille-coupling, and ring-closing metathesis. The target molecule was successfully synthesized in a 7-step linear sequence with a 20% overall yield starting from 2,4,6-trihydroxy benzoic acid, or a 12-step sequence with a 12.95% overall yield starting from R(+)-propylene oxide.
LETTERS IN ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
N. K. Chouhan, Sudarshana K. Ananthabhat, Sandeep Vaidya, P. Srihari
Summary: A highly efficient and scalable process for the synthesis of novoldiamine and hydroxynovaldiamine from levulinic acid has been achieved. These compounds are crucial intermediates for the synthesis of antimalarial drugs chloroquine, hydroxychloroquine, and mepacrine.
SYNTHETIC COMMUNICATIONS
(2022)
Article
Biochemistry & Molecular Biology
Ganesh Kumar Raut, Genji Sukumar, Moumita Chakrabarti, Jolly Janette Mendonza, Srihari Pabbaraja, B. Jagan Mohan Reddy, Ramakrishna Sistla, Sai Balaji Andugulapati, Manika Pal Bhadra
Summary: Polyphenols are natural compounds with anti-tumorigenic effects. This study designed and synthesized a compound that interferes with the cell cycle progression in aggressive prostate cancer. Further experiments showed that the compound inhibits the viability of prostate cancer cells and induces apoptosis through oxidative stress. In a mouse model, the compound showed no toxicity and reduced the tumor burden.
Review
Chemistry, Organic
Saumitra Sengupta, Srihari Pabbaraja, Goverdhan Mehta
Summary: Recursive Anionic Cyclization (RAC) is a mechanistically distinct domino strategy that continues to grow. By using nitroalkanes as a source of recursive carbanions, it has created a unique operating space for generating molecular complexity and diversity. The recursive nitronate cyclization, based on a domino [5 C+1 C] cyclization strategy, allows rapid access to densely functionalized carbo- and heterocycles with multiple chiral centers and regio-, stereo- and enantioselectivity. Extension to aromatic domains, particularly through benzannulation reactions, has further expanded the operating space. The functional versatility of nitro group has also been leveraged for post-domino modifications, leading to total synthesis of various natural products.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Srihari Pabbaraja, Bharath Kumar Yasam
Summary: A flexible stereoselective and convergent cum divergent approach to the synthesis of two 13-membered macrolides through a common skeleton is described. The synthesis is achieved using two different routes, resulting in a good overall yield. Key synthetic reactions include Keck allylation, Evans asymmetric methylation, Grubbs metathesis, and Julia-Kocienski olefination.
Article
Chemistry, Organic
Bhushan Mahajan, Dnyaneshwar Aand, Mandeep Purwa, Taufiqueahmed Mujawar, Subhash Ghosh, Srihari Pabbaraja, Ajay K. Singh
Summary: Researchers have used a nanotextured Ni@Cu material embedded electro microflow reactor to synthesize biphenyls in a fast and efficient manner, without the use of noble metals. By optimizing the reactor volume and integrating the process system, they have successfully achieved gram-scale biphenyl synthesis and continuous microflow synthesis of daclatasvir.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Physical
Deepak Kumar Jaiswal, Dnyaneshwar Aand, Puchakayala Krishna Rao, Sibaji Nandi, Srihari Pabbaraja, Ajay K. Singh
Summary: The deactivation of toxic gases and the separation of liquids through metal-organic frameworks (MOFs) have made significant advancements in this growing field. However, the stability of MOFs and their sensitivity to water are still being developed. In this study, a new strategy using scalable and safely generated continuous flow diazomethane is proposed to seal moisture-sensitive functionality in hydrophobic MOFs, demonstrating improved hydrophobicity and its applications in organic/aqueous phase separation and self-cleaning. This work presents the first attempt to seal sensitive functional groups with diazomethane for hydrophobic MOFs, exploring a new proof of concept for designing stable MOFs with controlled wettability. The concept of MOF diazomethane treatment can also be expanded to design and develop advanced membranes for effectively separating aqueous organic solutions, providing valuable insights.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Organic
Manas Jyoti Sarma, K. A. Sudarshana, Goverdhan Mehta, Pabbaraja Srihari
Summary: This study reveals the discovery of reaction regime controlled product diversification in a one-pot reaction between diynones and dimethyl-1,3-acetonedicarboxylate (DMAD), which selectively furnishes either functionally unique pentasubstituted o-alkynylbenzoates or fully substituted furan-3(2H)-ones. Furthermore, the potential of these two versatile platforms to enter new utilitarian chemical space has been explored.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Manas Jyoti Sarma, K. A. Sudarshana, Srihari Pabbaraja, Goverdhan Mehta
Summary: Spiroannulation of oxindole-3-oxy acrylates with ynones involving two overlapping, base differentiated cascades has been observed. The initial tandem Michael-Michael cascade delivers a pair of spiroannulated diastereomers, while a second multistep cascade involving stereoselective restructuring leads to the formation of 3H-spiro[furan-2,3'-indolin]-2'-ones with functional amplification and scrambling. This new scaffold can be synthesized in one flask from ynones and oxindole-3-oxy acrylates.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Review
Chemistry, Multidisciplinary
Saumitra Sengupta, Srihari Pabbaraja, Goverdhan Mehta
Summary: Intrusion into the C-H chemical space of natural products through C-H functionalization reactions can create new molecular diversities and impact biological functions. Semisynthetic C-H modification of natural products is becoming a minimalistic approach in drug discovery. Examples of C-H modification of natural products resulting in improved pharmacological attributes and opportunities in allied areas continue to be reported. This article highlights the evolving paradigm of natural product and synthetic chemistry research to accelerate and broaden natural product-based drug discovery.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Naresh Gantasala, Corentin Fournet, Myriam Le Roch, Claudia Lalli, Srihari Pabbaraja, Nicolas Gouault
Summary: A novel approach for constructing 2-spiropiperidine moieties was developed using dihydropyridones. The addition of allyltributylstannane onto dihydropyridones promoted by triflic anhydride resulted in the formation of gem bis-alkenyl intermediates, which were then converted to the corresponding spirocarbocycles through ring closing metathesis with high yields. The vinyl triflate group generated on these 2-spiro-dihydropyridine intermediates could be successfully utilized as a chemical expansion vector for Pd-catalyzed cross-coupling reactions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Medicinal
Mani Sharma, S. S. S. S. Sudha Ambadipudi, Neeraj Kumar Chouhan, V. Lakshma Nayak, Srihari Pabbaraja, Sai Balaji Andugulapati, Ramakrishna Sistla
Summary: Therapeutically active lipids in drug delivery systems can enhance the safety and efficacy of treatment. The liposome formulation created using synthesized biologically active lipids showed additive anti-cancer effects and reduced tumorigenic potential.
BIOORGANIC & MEDICINAL CHEMISTRY LETTERS
(2024)
Article
Chemistry, Multidisciplinary
Gandhari Kishor, Vankudoth Ramesh, Vadithya Ranga Rao, Srihari Pabbaraja, Praveen Reddy Adiyala
Summary: An efficient visible-light driven continuous-flow C-3-alkylation of quinoxalin-2(1H)-ones was achieved using Katritzky salts as alkylating agents. The reaction was catalyzed by eosin-y and base DIPEA at room temperature. The protocol utilized inexpensive alkyl amines and amino acid feedstocks to synthesize a variety of C-3-alkylated quinoxalin-2(1H)-ones. The reaction was carried out in a PFA capillary microreactor under blue LED irradiation, resulting in excellent yields and shorter reaction times compared to a batch system.
