Article
Chemistry, Multidisciplinary
Yuki Saito, Shu Kobayashi
Summary: The article discusses the application of chiral heterogeneous Sc catalysts in continuous-flow reactions, achieving efficient synthesis of compounds through noncovalent interactions and the crucial role of heteropoly acid.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Biochemistry & Molecular Biology
Mohammad Shahidul Islam, M. Ali, Abdullah Mohammed Al-Majid, Abdullah Saleh Alamary, Saeed Alshahrani, Sammer Yousuf, Muhammad Iqbal Choudhary, Assem Barakat
Summary: The Friedel-Crafts reaction between substituted indoles as nucleophiles with chalcones-based benzofuran and benzothiophene scaffolds was successfully achieved using a highly efficient bimetallic iron-palladium catalyst system, resulting in a series of bis-heteroaryl products with certain anticancer activities.
Article
Chemistry, Organic
Louis Chassillan, Yasuhiro Yamashita, Woo-Jin Yoo, Martial Toffano, Regis Guillot, Shu Kobayashi, Giang Vo-Thanh
Summary: The enantioselective hydrophosphonylation of N-Boc imines was achieved using a new family of pseudo-symmetric guanidine-thiourea catalysts, with the catalyst being heterogenized by polymerization with styrene and applied to reactions under continuous-flow conditions. This approach provided alpha-amino phosphonates in moderate to high yields with good enantioselectivity.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Takanori Shibata, Natsumi Shiozawa, Shun Nishibe, Hideaki Takano, Satoshi Maeda
Summary: A chiral Pt(ii) complex was synthesized and used as an efficient catalyst for an intramolecular [4 + 2] cycloaddition reaction of biphenylenes, resulting in high yields and enantioselectivity at ambient temperature. DFT calculations revealed a Pt(ii)/(iv) cycle involving oxidative addition of biphenylene and C-C bond cleavage.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Physical
Ryoya Tajima, Takaaki Saito, Takayoshi Arai
Summary: The conventional acid-catalyzed aza-Friedel-Crafts reaction of phenols with imines typically shows ortho-selectivity. However, a chiral bis(imidazolidine) pyridine (PyBidine)-Ni(OAc)(2) catalyst can switch the regioselectivity to para-selectivity. This switch is facilitated by the bulky PyBidine-Ni(OAc)(2) catalyst with a Ph2CHCH2 substituent, resulting in highly para-selective aza-Friedel-Crafts reactions (up to 99:1 para/ortho selectivity).
Article
Chemistry, Organic
Jie Zheng, Meng-Yu Rong, Fang-Fang Feng, Fa-Guang Zhang, Chi Wai Cheung, Jun-An Ma
Summary: In this study, the organocatalytic asymmetric aza-Friedel-Crafts-type reaction of indol-3-ones with 1- and 2-naphthols was performed using spirocyclic chiral phosphoric acids and quinine-incorporated squaramides as the organocatalysts. Two classes of structurally distinct chiral compounds, namely 2-(hydroxylnaphthyl)-indolin-3-ones and tetrahydrofuroindoles, were formed. These quaternary centre-containing indoline derivatives may have applications in the synthesis of biologically active molecules.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Hamdiye Ece, Yuji Tange, Taiga Yurino, Takeshi Ohkuma
Summary: 3-Aryloxindole derivatives were synthesized via a Friedel-Crafts-type cyclization, catalyzed by a trimethylsilyl tricyanopalladate complex. Various diethyl phosphates derived from N-arylmandelamides were efficiently converted into oxindoles, with the use of N,N-dibenzylamide leading to a benzo-fused delta-lactam. Substitution reactions on oxindole products yielded 3,3-diaryloxindoles with two different aryl groups.
Article
Chemistry, Physical
Shradha Gandhi, Vandana Sharma, Ishfaq S. Koul, Sanjay K. Mandal
Summary: This study explores the Lewis acidic nature of a coordination polymer and its nanostructures, and finds that 1D nanorods exhibit exceptional catalytic activity in Knoevenagel condensation and Strecker reactions, while the coordination polymer is more suitable for Friedel-Crafts alkylation reaction. These catalysts are highly efficient and recyclable.
Article
Chemistry, Organic
Sk Md Samim Akhtar, Sukanta Bar, Saumen Hajra
Summary: A proficient stereoselective aminoarylation reaction of N-cinnamylanilines was developed based on a two-step protocol involving catalytic enantioselective aziridination and subsequent 6-endo-tet Friedel-Crafts cyclization. The reaction showed excellent diastereo- and enantioselectivity in the synthesis of trans-3-amino-4-aryltetrahydroquinolines, with the potential for concise synthesis of bioactive compounds.
Article
Chemistry, Organic
Avijit Roy, Haopeng Gao, Hendrik F. T. Klare, Martin Oestreich
Summary: The electrophilic silylium ions were used to investigate the intramolecular Friedel-Crafts-type cyclization of aryl tethered 1,1-difluoroalkenes. The preference for electrophilic silylation of the carbon-carbon double bond over vinylic C(sp(2))-F bonds activation initiates the reaction. Subsequent cyclization and hydrodefluorination of the resulting C(sp(3))-F bonds produce the final product in moderate to good yields. Unlike previous reports, the reaction proceeds with perfluorinated tetraphenylborate counteranion under ambient conditions without the need for a carborate counteranion associated with the silylium ion intermediates.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Amjad Ali, Raveena Jajoria, Harish K. Harit, Ravi P. Singh
Summary: In this study, the addition of alpha-ketoamide top-quinone methide initiated by dialkylphosphite in the presence of organic base DBU was explored. The coupling of dialkylphosphites to alpha-ketoamides followed[1,2]-phospha-Brook rearrangement, generating alpha-phosphonyloxy enolates that were subsequently seized by p-quinonemethides. This two-step one-pot 1,6-conjugate addition method provides effective access to a series of isatin-incorporated phosphate-bearing 1,6-adducts with high yield and selectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Samim Akhtar, Saumen Hajra
Summary: A one-pot asymmetric aminoarylation reaction has been developed for the synthesis of trans-4-amino-5-aryltetrahydrobenzo[c]azepines with excellent diastereo- and enantioselectivity. The reaction proceeds through aziridination followed by intramolecular cyclicization. A chiral indenyl bis(oxazoline) ligand is found to be effective for the catalytic enantioselective version of this one-pot transformation.
Review
Chemistry, Organic
Sanjay Singh, Chinmoy K. Hazra
Summary: This review discusses recent advances and significant breakthroughs in the catalytic Friedel-Crafts alkylation of targeted arenes or heteroarenes, with a main focus on literature published between 2015 and March 2023.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Multidisciplinary
Yangmian Lu, Jindong Li, Weizhi Gu, Ning Li, Zhenggen Zha, Zhiyong Wang
Summary: A series of pyrazolone derivatives bearing a tetrasubstituted chiral center were successfully synthesized via a Lewis acid-catalyzed reaction using a chiral copper complex as the catalyst. The reaction proceeded smoothly under mild conditions, giving high yields (up to 85%) and excellent enantioselectivities (up to 99%). The gram scale synthesis also demonstrated the practicality of this reaction.
CHINESE CHEMICAL LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Mikhail Soldatov, Yiqi Wang, Hongzhi Liu
Summary: Phosphazene-containing porous materials and cage-like silsesquioxanes are promising for catalytic applications, with the former serving as adsorbents and basic catalysts while demonstrating high efficiency in the Knoevenagel reaction. This study highlights the potential of porous polymers based on organosiloxane compounds as basic catalysts for various reactions, opening up new perspectives in the field.
CHEMISTRY-AN ASIAN JOURNAL
(2021)
Article
Chemistry, Applied
Shuichi Nakamura, Natsuki Matsumoto, Masato Kibe, Kazuki Abe, Tsunayoshi Takehara, Takeyuki Suzuki
Summary: This study reports the enantiodivergent reaction of ketimines derived from alpha-ketoesters with malononitriles using a single chiral source, resulting in the synthesis of various optically active compounds from the obtained malononitrile-derived alpha-amino acids. A proposed reaction mechanism explains the observed enantiodivergency in high yields with high enantioselectivities.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Yusuke Oyamada, Kazuto Inaba, Takahiro Sasamori, Shuichi Nakamura
Summary: This study achieved high enantioselectivity in the reaction of imines by introducing a cyano group as an activating group. The density functional theory (DFT) calculation clarified the stereochemical outcome and importance of the N-cyano group in the reaction.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Naoki Yasukawa, Ami Yamanoue, Tsunayoshi Takehara, Takeyuki Suzuki, Shuichi Nakamura
Summary: The first enantioselective aza-Henry reaction of non-activated cyclic iminoesters, derived from cyclic amino acids, has been developed using a unique cinchona alkaloid sulfonamide/zinc(ii) catalyst. Good yields and enantioselectivities were observed, and the stereochemistry was explained by proposed transition state based on experiments and DFT calculations.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Shuichi Nakamura, Yoichiro Matsuda, Tsunayoshi Takehara, Takeyuki Suzuki
Summary: The first enantioselective Pictet-Spengler reaction of acyclic alpha-ketoesters with tryptamines has been successfully developed. Chiral imidazoline-phosphoric acid catalysts were found to provide excellent yields and enantioselectivity for the reaction. Density functional theory calculations revealed possible transition states, explaining the origin of chiral induction. This process offers an efficient route for the synthesis of tetrahydro-beta-carboline derivatives.
Article
Multidisciplinary Sciences
Satoshi Yamanaka, Yuto Horiuchi, Saya Matsuoka, Kohki Kido, Kohei Nishino, Mayaka Maeno, Norio Shibata, Hidetaka Kosako, Tatsuya Sawasaki
Summary: This article introduces a method based on AirID to identify drug-induced neo-substrates through proximity-dependent biotinylation. The study identifies several new CRBN substrates and demonstrates that this method can serve as a general strategy for studying drug-induced protein-protein interactions in cells.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Kazuki Ogura, Itsuki Isozumi, Tsunayoshi Takehara, Takeyuki Suzuki, Shuichi Nakamura
Summary: In this study, the first enantioselective hydrophosphonylation of ketimines with phosphine oxides was developed. The reaction using a bis(imidazoline)-phosphoric acid catalyst resulted in chiral alpha-quaternary aminophosphorous compounds with a primary amino group in excellent yields and enantioselectivities. Transition states were proposed based on experimental results and DFT calculation to explain the stereoselectivity of the reaction.
Article
Chemistry, Applied
Yusuke Oyamada, Shintaro Yamasaki, Mika Tsuzuki, Takumi Kitagawa, Masaru Kondo, Takahiro Sasamori, Shuichi Nakamura
Summary: The catalytic enantioselective allenylation of ketimines derived from isatins is reported. High regio- and enantioselective products were obtained using a bis(imidazoline)-palladium catalyst. The obtained products were further converted into various chiral amines. The stereoselectivity origin was revealed by DFT calculations of the transition state.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Applied
Yuka Iizuka, Tatsumi Wada, Kazuki Ogura, Tsunayoshi Takehara, Takeyuki Suzuki, Shuichi Nakamura
Summary: The first enantioselective synthesis of cyclic N,S-ketals having tetrasubstituted chiral center through intramolecular cyclization has been developed. The reaction using a chiral imidazoline-phosphoric acid catalyst shows high enantioselectivity.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Norio Shibata, Dominique Cahard
Summary: From 2000, our two research groups independently and simultaneously designed and developed a novel family of electrophilic fluorinating reagents based on the use of Cinchona alkaloids. The chiral N-fluoro ammonium salts demonstrated the highest efficiency compared to prior art in enantioselective electrophilic fluorination for a wide range of substrates. In this account, we tell our respective stories, how the same idea germinated in our laboratories, the characterization of the chiral reagents, the use in stoichiometric quantity then the development of a catalytic version, the application to the synthesis of chiral fluorinated molecules of pharmaceutical interest, and finally the exploitation of our reagents by other teams and for other applications.
Review
Chemistry, Multidisciplinary
Yuji Sumii, Norio Shibata
Summary: The trifluoromethyl group is a crucial component in drugs and polymers, making the development of trifluoromethylation reactions a significant area of research in organic chemistry. Various methods, including nucleophilic and electrophilic approaches, transition-metal catalysis, photocatalysis, and electrolytic reactions have been developed over the years. Microflow versions of these reactions have shown great potential for industrial applications due to their scalability, safety, and time efficiency. This review discusses the current state of microflow trifluoromethylation, focusing on different trifluoromethylation reagents and techniques such as continuous flow, flow photochemical, microfluidic electrochemical reactions, and large-scale microflow reactions.
Letter
Chemistry, Organic
Elsayed M. Mahmoud, Soichiro Mori, Yuji Sumii, Norio Shibata
Summary: The synthesis of acyl fluorides from carboxylic acids is achieved using Selectfluor mediated by elemental sulfur. A wide range of acyl fluorides can be accessed while avoiding the formation of acid anhydrides. F-19 NMR spectra indicate that the reactive species in this deoxyfluorination reaction are the in situ generated S-8-fluoro-sulfonium cation A and neutral S-8-difluoride A'.
Article
Chemistry, Organic
Shuichi Nakamura, Masato Kibe, Tsunayoshi Takehara, Takeyuki Suzuki
Summary: The first enantioselective reaction of alpha-isocyanoacetonitriles was established using cinchona alkaloid amide-Cu(II) catalysts, resulting in imidazolines with tetrasubstituted stereogenic carbon centers. The reaction exhibited high diastereo- and enantioselectivities, which were explained by control experiments and density functional theory calculations. The conversion of the products into chiral compounds demonstrated the potential application of alpha-isocyanoacetonitriles in asymmetric and organic syntheses.
Article
Multidisciplinary Sciences
Jun Zhou, Zhengyu Zhao, Norio Shibata
Summary: Defluorinative cross-coupling between amines and organic fluorides is achieved via a silylboronate-mediated strategy. This method enables the room-temperature cross-coupling of C-F and N-H bonds, avoiding the high energy barriers associated with thermally induced S(N)2 or S(N)1 amination. The selective activation of the C-F bond of organic fluorides by silylboronate is a significant advantage of this transformation.
NATURE COMMUNICATIONS
(2023)
Editorial Material
Chemistry, Multidisciplinary
Norio Shibata, Dinesh Talwar
Summary: The unique properties and applications of fluorine-containing molecules have had significant impact across different scientific fields, from small to large molecules. This special issue provides a comprehensive overview of the state-of-the-art in fluorine chemistry.
Article
Chemistry, Multidisciplinary
Jun Zhou, Zhengyu Zhao, Bingyao Jiang, Katsuhiro Yamamoto, Yuji Sumii, Norio Shibata
Summary: In this study, an efficient silylboronate-mediated cross-coupling reaction of aryl fluorides with arylalkanes was developed under transition-metal-free, room-temperature conditions. The method showed good adaptability to aryl fluorides with a C(sp(2))-F bond and can be extended to other coupling partners with a C(sp(3))-H bond. It provides a practical and convenient approach to obtain di- and triarylalkanes with tertiary or quaternary carbon centers.