Article
Chemistry, Multidisciplinary
Tibor Penaska, Viktoria Modrocka, Klara Stankovianska, Maria Meciarova, Erik Rakovsky, Radovan Sebesta
Summary: This study achieves enantioselective and diastereoselective synthesis of densely substituted chiral pyran derivatives by using amino-thiourea or quinine organocatalyst under ball-milling conditions. Liquid-assisted grinding proves to be a highly efficient means of obtaining pyrans in high yield, with high enantiomeric purities and short reaction times.
Article
Chemistry, Multidisciplinary
Heng-Zhi Tian, Qing-Gang Tang, Guo-Qiang Lin, Xing-Wen Sun
Summary: A novel approach to synthesize chiral 1,2-oxazinane spirocyclic scaffolds by organocatalytic [4 + 2] cycloaddition reaction has been developed. In addition, a hydrazide 1,4-synthon is synthesized to construct chiral hexahydropyridazin spirocyclic scaffolds. Both reactions exhibit good to excellent yield, diastereoselectivity, and enantioselectivity.
Article
Chemistry, Multidisciplinary
Jie Ouyang, Rajat Maji, Markus Leutzsch, Benjamin Mitschke, Benjamin List
Summary: Here, we report the design of a highly enantioselective, catalytic (4 + 3) cycloaddition reaction enabled by strong and confined IDPi Lewis acids. This reaction allows the synthesis of novel compounds with multiple stereocenters from gem-dialkyl 2-indolylalcohols and dienolsilanes. The method exhibits broad substrate scope and versatile downstream chemical modifications. Density functional theory-supported mechanistic studies reveal the significance of the in-situ generated silylium species in an overall concerted yet asynchronous cycloaddition.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Casper L. Barlose, Niklas L. ostergaard, Rene S. Bitsch, Marc V. Iversen, Karl Anker Jorgensen
Summary: An enantioselective methodology for constructing trans-Diels-Alder scaffolds with up to five contiguous stereocenters is presented, utilizing a halogen effect and a novel discovered pseudo-halogen effect. The reaction involves an endo-selective, secondary-amine catalyzed Diels-Alder reaction followed by a subsequent S(N)2-like reaction at a tertiary center to obtain the trans-Diels-Alder scaffold. The mechanism was supported by experimental results and computational studies.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Haijing Zhong, Tengbo Ding, Qifeng Guo, Zeng Tian, Pei Yu, Xiaojian Jiang
Summary: A catalytic asymmetric halocyclization protocol has been developed to synthesize morpholines containing a quaternary stereocenter. Various chlorinated 2,2-disubstituted morpholines were obtained in excellent yields and enantioselectivities under mild conditions using cinchona alkaloid-derived phthalazine as the catalyst.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Review
Chemistry, Multidisciplinary
Victor Laina-Martin, Jose A. Fernandez-Salas, Jose Aleman
Summary: Cycloaddition reactions, particularly Diels-Alder reactions, are regarded as powerful methodologies for building carbon-carbon bonds. The inverse-electron-demand hetero-Diels-Alder reactions have been a significant breakthrough for synthesizing heterocyclic compounds. Among them, the organocatalytic enantioselective version has been extensively studied due to its asymmetric construction of diversely functionalized scaffolds under green chemistry conditions.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Qi Xue, Ren Wang, Wen-Yu Zhang, Fang-Fang Shen, Yang Li, Qing Sun, Jin-Heng Li
Summary: A new palladium-catalyzed multicomponent dearomatization of arylamines with CO and propargylic acetates for the synthesis of bridged polycyclic lactams is reported. This method enables double annulation at the ipso and para positions of the amino group, leading to the formation of four new bonds, including three C-C bonds and one C-N bond. DFT calculations and experimental studies suggest that the efficient formation of the allenecarboxanilide intermediate is crucial for the dearomative transformation.
Article
Chemistry, Multidisciplinary
Xin-Qi Zhu, Qian Wang, Jieping Zhu
Summary: This study reports chiral phosphoric acid-catalyzed enantioselective Diels-Alder reactions and three-component reactions, which can efficiently synthesize compounds with multiple functional groups in high yields and stereoselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Nicolaj Inunnguaq Jessen, Giulio Bertuzzi, Maksimilian Bura, Mette Louise Skipper, Karl Anker Jorgensen
Summary: The study developed an enantioselective [12+2] cycloaddition for constructing a chiral cycl[3.2.2]azine core, with focus on the reaction mechanism through combined experimental and computational investigations. The reaction exhibited excellent selectivity and yields, with robust adaptability to various electron-deficient 2π-components.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Review
Chemistry, Organic
Marcos Escolano, Daniel Gavina, Javier Torres, Santiago Diaz-Oltra, Carlos del Pozo
Summary: The organocatalytic enantioselective desymmetrization reaction via intramolecular (hetero)Michael addition is an effective strategy for creating complex carbo- and heterocycles with multiple stereocenters in a simple manner. The main challenge lies in the design and synthesis of the starting materials.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Chemistry, Organic
Rambabu Chegondi, Srilaxmi M. Patel, Sundaram Maurya, Ashok Donthoju
Summary: This mini-review provides an overview of recent developments in the field of organocatalytic enantioselective desymmetrization, along with a brief discussion on future perspectives.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Satish B. Thopate, Lakshmi Revati Magham, Shrabani Dinda, Rambabu Chegondi
Summary: This work presents the development of an unconventional and highly enantioselective solvent-promoted Rauhut-Currier cyclization of enal-tethered cyclohexadienone. The reaction involves the reactivity of a Jorgensen-Hayashi catalyst through the merging of iminium and enamine activation. The asymmetric desymmetrization reaction shows broad substrate scope with good yields and high to excellent enantioselectivity. DFT calculations suggest that the rate-limiting step is the elimination of the alkoxy group, which proceeds through proton abstraction by solvent instead of a direct 1,3-proton shift.
Article
Chemistry, Organic
Subhajit Mondal, Santanu Mukherjee
Summary: The first atroposelective desymmetrization of prochiral N-aryl maleimides through its conversion to axially chiral phthalimides is achieved using a de novo arene construction strategy. Catalyzed by bis(3,5-dimethylphenyl)prolinol TMS-ether, this reaction selectively generates products with excellent enantioselectivity at a chiral C-N axis remote from the reaction sites (up to 97.5:2.5 er).
Review
Chemistry, Multidisciplinary
Yin Xu, Tong-Yi Zhai, Zhou Xu, Long-Wu Ye
Summary: Desymmetrization is a practical and efficient strategy in synthetic chemistry for assembling valuable molecular complexity. Organocatalysis has become a powerful tool in asymmetric catalysis, and recent progress has been made in combining organocatalysis with desymmetrization.
TRENDS IN CHEMISTRY
(2022)
Article
Chemistry, Organic
Ashok Donthoju, Anandarao Munakala, Sushma Ellandula, Rambabu Chegondi
Summary: In this study, we have reported a palladium(0)-catalyzed decarboxylative oxa-Michael addition/remote alpha-allylation/1,3-migration reaction with high yields. The reaction is triggered by a base-mediated retro-Michael ring-opening reaction and subsequent syn-selective oxa-Michael addition.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Ryukichi Takagi, Kenji Tanaka, Koumei Yamamoto, Yoshikazu Hiraga, Satoshi Kojima, Manabu Abe
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN
(2015)
Article
Chemistry, Organic
Jianfei Xue, Manabu Abe, Ryukichi Takagi
JOURNAL OF PHYSICAL ORGANIC CHEMISTRY
(2017)
Article
Plant Sciences
Mai T. T. Nguyen, Tho H. Le, Hai X. Nguyen, Phu H. Dang, Truong N. V. Do, Manabu Abe, Ryukichi Takagi, Nhan T. Nguyen
JOURNAL OF NATURAL PRODUCTS
(2017)
Article
Chemistry, Organic
Phu H. Dang, Hanh H. T. Nguyen, Hien T. T. Truong, Truong N. V. Do, Hai X. Nguyen, Mai T. T. Nguyen, Manabu Abe, Ryukichi Takagi, Nhan T. Nguyen
TETRAHEDRON LETTERS
(2017)
Article
Chemistry, Organic
Ryukichi Takagi, Emi Fujii, Hirotoshi Kondo
JOURNAL OF ORGANIC CHEMISTRY
(2018)
Article
Chemistry, Organic
Ryukichi Takagi, Yuichiro Sakai, Duyen Thi Duong
Summary: A binaphthyl derivative with bis(trifluoromethanesulfonimide) (BSI) moiety was developed as a novel Bronsted acid, showing strong acidity in computational prediction. BSI efficiently catalyzed the hydroamination of alkenyl amines and hydroalkoxylation of alkenyl alcohols in HFIP, with adjacent sulfonimide groups playing a crucial role in enhancing acidity.
Article
Chemistry, Multidisciplinary
Ryukichi Takagi, Yuhei Yamasaki
Summary: In this study, alkaline earth metal salts of chiral bis-sulfonimide were prepared and used as catalysts for asymmetric Diels-Alder reactions. The results showed moderate stereo selectivity in the cycloaddition product formed between 2-propenoyl pyrazole and cyclopentadiene catalyzed by the calcium salt.
Article
Chemistry, Organic
Ryukichi Takagi, Duyen Thi Duong, Toshiya Ichiki
Summary: The study examined the asymmetric intramolecular hydroamination of alkenyl thiourea catalyzed by Disulfonimide (DSI). The reaction proceeded even under dilute concentrations and high temperatures, yielding the hydroamination product with good chemical yield and moderate enantioselectivity. Density functional theory (DFT) calculations supported a mechanism involving the thiourea moiety of the alkenyl amine as a dual hydrogen bond donor.
Article
Chemistry, Multidisciplinary
Qianghua Lin, Runzhao Guo, Kozue Hamao, Ryukichi Takagi, Manabu Abe
Summary: Due to UV light-induced cell damage, photoremovable protecting groups (PPGs) that can be removed using visible or near-infrared light have gained attention. A novel PPG, 2-(4-nitrophenyl)-1H-indolyl-3-methyl chromophore (NPIM), was synthesized. Various compounds were protected using this PPG and then deprotected using visible or near-infrared light. The low cytotoxicity of NPIM suggests its potential application in physiological studies.
Article
Chemistry, Organic
Ryukichi Takagi, Takaaki Tanimoto
Summary: In this study, an enantioselective intra- and intermolecular [2 + 2] photocycloaddition of quinolone using a C-1-symmetric chiral phosphoric acid as a visible-light photocatalyst was developed. The thioxanthone chromophore on the phosphoric acid played a crucial role in both phototransformation and enantioselectivity.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Organic
Ryukichi Takagi, Duyen Thi Duong
Summary: This study used density functional theory calculations to investigate the mechanism of enantioselective intramolecular hydroamination catalyzed by chiral binaphthol N-triflylphosphoramide (NPTA). It reveals the details of the hydrogen bonding mode between NPTA and the substrate, emphasizing the importance of the dual hydrogen binding properties of the thiourea moiety for the reactivity and stereoselectivity of the hydroamination.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Ryukichi Takagi, Chihiro Tabuchi
ORGANIC & BIOMOLECULAR CHEMISTRY
(2020)
Article
Chemistry, Organic
Jianfei Xue, Ryukichi Takagi, Manabu Abe
Article
Chemistry, Multidisciplinary
Satish Jakkampudi, Manabu Abe, Naomitsu Komori, Ryukichi Takagi, Ko Furukawa, Claudine Katan, Wakako Sawada, Noriko Takahashi, Haruo Kasai
Article
Chemistry, Organic
Faiza Diaba, Gisela Trenchs
Summary: The first violet light-mediated synthesis of gamma- and delta-lactams from N-alkenyl trichloroacetamides is reported in this paper. The reactions are conducted in tetrahydrofuran or 2-methyltetrahydrofuran as the sole solvent without catalysts or additives, under non-anhydrous conditions in an air atmosphere where the solvent serves as the radical initiator.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Feroze Hussain, Sajjad Ahmed, Ashiq Hussain Padder, Qazi Naveed Ahmed
Summary: This study reports a novel and efficient one-pot synthesis method for mixed phosphorotrithioates, which does not require supplementary additives and shows broad applicability.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Hyunjin Oh, Ikyon Kim
Summary: A new 1,2,4-triazole-pyrrolo[1,2-a]pyrazine hybrid system, 6-acylpyrrolo[1,2-a][1,2,4]triazolo[5,1-c]pyrazine, was synthesized using a catalyst-free method. This method involved sequential exposure of pyrrole-2-carbonitrile-derived substrates to DMF-DMA and acyl hydrazide, resulting in the formation of acylated pyrazine and 1,2,4-triazole rings, enabling the installation of various substituents at specific positions on the core skeleton.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Ming Yan, Si-fan Wang, Yong-po Zhang, Jin-zhong Zhao, Zhuo Tang, Guang-xun Li
Summary: Here we developed an efficient photocatalytic approach for the convenient preparation of sulfinamides. The reaction allows for the gram-scale preparation of sulfinamides and the one-pot synthesis of various sulfonyl amides.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Farzaneh Bandehali-Naeini, Zahra Tanbakouchian, Noushin Farajinia-Lehi, Nicolas Mayer, Morteza Shiri, Martin Breugst
Summary: Two tandem catalytic systems were developed for the synthesis of novel 3,4-disubstituted maleimides using the same Ugi adducts. Different maleimide structures can be synthesized using either Pd or Cu catalysis.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Tanya Raghava, Anjan Chattopadhyay, Subhadeep Banerjee, Nivedita Sarkar
Summary: Amine substitution of two ortho fluorine atoms of tetrafluoroterephthalonitrile through SNAr chemistry is easily achievable. But further fluorine substitution is only possible under forcing conditions, yielding valuable fluorophores for bioimaging.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Review
Chemistry, Organic
Anju Chadha, Santosh Kumar Padhi, Selvaraj Stella, Sowmyalakshmi Venkataraman, Thangavelu Saravanan
Summary: Alcohol dehydrogenases are enzymes that use cofactors for oxidation or reduction reactions of alcohols or carbonyl compounds. They are utilized in green chemistry and have applications in the production of pharmaceuticals. Recombinant enzymes have solved the challenge of producing purified enzymes in large quantities. Engineered alcohol dehydrogenases have been used in asymmetric synthesis in industry. Various methods have been established for regenerating expensive cofactors to make the enzymatic process more efficient and economically viable.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
