Article
Chemistry, Organic
Yusuke Tomita, Naoto Haraguchi, Sayori Kiyota, Nobuyuki Komine, Masafumi Hirano
Summary: A traditional cobalt catalyst system has been found to exhibit previously undiscovered reactivity. Depending on the choice of tertiary phosphines and substrates, this catalytic system can catalyze diverse cycloadditions, yielding various cyclic compounds. The bite angles of the ligands used significantly contribute to the catalytic diversity.
Article
Chemistry, Inorganic & Nuclear
Kevin Blaesing, Jonas Bresien, Steffen Maurer, Axel Schulz, Alexander Villinger
Summary: The Lewis acids GaCl3 and B(C6F5)(3) were used to treat Me3Si-X (X=CN, N-3, OCN, and SCN) in toluene, resulting in the desired adducts Me3Si-X -> GaCl3 and Me3Si-X -> B(C6F5)(3). The synthesized adducts were isolated, characterized, and analyzed for their structures, thermodynamics of formation, and charge transfer effects.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Kento Nagai, Suguru Morishitabara, Yuji Nishi, Chihiro Kajimoto, Motohiro Yasui, Takashi Yumura, Shigeyuki Yamada, Tsutomu Konno
Summary: In this study, highly regioselective hydrosilylation of cyclohexa-1,3-dienes bearing a tetrafluoroethylene group was achieved under mild conditions using 1-10 mol % Co-2(CO)(8) as the catalyst. Mechanistic studies and DFT calculations demonstrated that the reaction proceeds via the modified Chalk-Harrod mechanism, leading to the exclusive formation of homoallylsilanes. The successful synthesis of a tetrafluorinated negative-type liquid crystal showcased the synthetic utility of this hydrosilylation reaction.
Article
Chemistry, Organic
Manman Sun, Rong Zhong, Jinshan Li, Yongmin Ma, Jianguo Yang, Zhiming Wang
Summary: A metal-free 1,4-allylation of azadienes with allyltrimethylsilanes catalyzed by B(C6F5)(3) has been developed. The high Lewis acidity, good thermal stability, and good hydrolytic stability of the catalyst make this reaction efficient and operationally simple. Benzofuran-, indene-, dihydronaphthalene-, chromene-, and benzothiophene-based allyl arylmethanes have been obtained in up to 95% yield.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Miaomiao Zhou, Ting Wang, Gui-Juan Cheng
Summary: Selective defunctionalization of synthetic intermediates is a valuable approach in organic synthesis, and the recently developed B(C6F5)(3)/hydrosilane-mediated reductive deamination reaction of primary amines has important applications.
FRONTIERS IN CHEMISTRY
(2022)
Article
Chemistry, Applied
Jiaming Zhou, Jin Huang, Changhui Lu, Huanfeng Jiang, Liangbin Huang
Summary: A B(C6F5)(3)-catalyzed hydroarylation of terminal alkynes with various phenols at room temperature was developed, leading to the synthesis of 2-gem-vinylphenols with good regio-selectivity. The transformations exhibited a broad substrate scope with moderate yields, and mechanism studies suggested the activation of phenol by B(C6F5)(3) followed by protonation of the alkyne/Friedel-Crafts-type reaction.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Applied
Ze-Jian Xue, Meng-Yao Li, Bin-Bin Zhu, Zhi-Tao He, Chen-Guo Feng, Guo-Qiang Lin
Summary: The palladium-catalyzed cross-coupling of ortho-vinyl aromatic bromides and olefins using a controllable 1,4-palladium migration/Heck cascade protocol is a mild, efficient, and highly stereoselective method for the synthesis of trisubstituted 1,3-dienes, especially triaryl-substituted ones.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Peng Wang, Yulin Gong, Xiaoyu Wang, Yangqing Ren, Lei Wang, Lele Zhai, Huilin Li, Xuegong She
Summary: Described herein is a B(C6F5)(3)-catalyzed S-H insertion reaction of thiophenols and thiols with alpha-diazoesters to access valuable alpha-thioesters. The reaction proceeds under solvent-free conditions at room temperature, and offers an expedient way for synthesis of thioether-containing compounds. The established protocol shows broad scope and functional group tolerance, with moderate to good yields of alpha-thioester products.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Chemistry, Organic
Lei Liu, Yonghui He, Chang-Peng Zou, Tao Ma, Xiu-Xiu Qiao, Yuntao Jiang, Ganpeng Li, Xiao-Jing Zhao
Summary: A Friedel-Crafts reaction between 2-aryl-3H-indol-3-ones and indolizines, catalyzed by B(C6F5)(3), is reported. This method provides a convenient route to C2-quaternary indolin-3-ones based on indolizine with high yields and regioselectivities. The resulting products can be further modified by N-methylation and trifluoromethane sulfonation.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Review
Chemistry, Organic
Feng Xiangqing, Du Haifeng
Summary: Organosilicon compounds, with their unique properties, have found wide applications in various fields. The silylation of unsaturated compounds has been recognized as an important approach for synthesizing organosilicon compounds, and significant progress has been made, particularly using B(C6F5)(3) as a catalyst.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jingyan Luo, Zhou Luo, Biqi Zhang, Qiuyu Zhao, Lu Liu, Yuanyuan Liu
Summary: We report a highly chemoselective consecutive C-H [2+3]-cyclative functionalization for the simultaneous formation of two C-C bonds, constructing polycyclic phenols without the use of metal catalyst. The catalytic system, using commercially available and low-cost B(C6F5)(3), tolerates a wide range of substrates and efficiently produces 2,6,7,8-tetrahydroacenaphthylen-3-ol-type polycyclic compounds. Additionally, several derivative reactions of the catalytic products demonstrate the potential application of this method in the synthesis of polycyclic compounds.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Andreas Erbs Hillers-Bendtsen, Jacob Lynge Elholm, Oscar Berlin Obel, Helen Hoelzel, Kasper Moth-Poulsen, Kurt V. Mikkelsen
Summary: In this paper, a large scale screening of bicyclic diene photoswitches was conducted using quantum chemical methods for molecular solar thermal energy storage. The systems with high solar energy conversion efficiencies and storage densities were identified, providing design guidelines for the next generation of molecular solar thermal energy storage systems.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Shi-Jun Wang, Jun-Jia Zhai, Long Wang, Xiang-Ying Tang
Summary: To better understand the activity of boron catalysts, synthesizing new structural variants is an important task in boron chemistry. This study introduces a simple strategy to consecutively regulate the catalytic activity of B(C6F5)3& H2O by adding an appropriate amount of tetrahydrofuran. The superiority of this strategy is demonstrated through a challenging nucleophilic substitution reaction of benzyl fluoride with alcohol.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Andreas Erbs Hillers-Bendtsen, Jacob Lynge Elholm, Oscar Berlin Obel, Helen Holzel, Kasper Moth-Poulsen, Kurt V. Mikkelsen
Summary: Photoswitches, molecular systems that undergo chemical transformations upon interaction with light, have potential applications in various new technologies. This paper presents a large-scale screening of approximately half a million bicyclic diene photoswitches using quantum chemical methods, specifically in the context of molecular solar thermal energy storage. The study also introduces an efficient strategy for scoring the systems based on predicted solar energy conversion efficiency and discusses potential pitfalls of this approach. The search through the chemical space of bicyclic dienes unveils systems with unprecedented solar energy conversion efficiencies and storage densities, providing promising design guidelines for next-generation molecular solar thermal energy storage systems.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Li-Qin Yan, Zhenzhen Yin, Xinwei He, Qianqian Li, Ruxue Li, Jiahui Duan, Keke Xu, Qiang Tang, Yongjia Shang
Summary: A novel and versatile approach has been developed for the construction of 12-phenacyl-11H-benzo[b]xanthene-6,11(12H)-dione derivatives through a copper-catalyzed cascade reaction. This method provides a highly efficient synthesis of these derivatives in a single step from readily available starting materials, forming new bonds and a heterocycle.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Haowei Ding, Ken Sakata, Shogo Kuriyama, Yoshiaki Nishibayashi
Article
Chemistry, Inorganic & Nuclear
Ken Sakata, Satoshi Shimada, Ryo Takeuchi
Article
Chemistry, Multidisciplinary
Ken Sakata, Hiroshi Fujimoto
Article
Chemistry, Multidisciplinary
Shiyao Liu, Yoshiaki Tanabe, Shogo Kuriyama, Ken Sakata, Yoshiaki Nishibayashi
Summary: In recent years, significant progress has been made in the development of transition metal-catalyzed enantioselective propargylic substitution reactions. However, until now, no successful example with phosphorus-centered nucleophiles has been reported. This study presents the first successful example of ruthenium-catalyzed enantioselective propargylic substitution reactions using propargylic alcohols as substrates and diarylphosphine oxides as phosphorus-centered nucleophiles, providing a new method for preparing chiral phosphorus-containing organic compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Ken Sakata, Yui Goto, Takeshi Yoshikawa, Yoshiaki Nishibayashi
Summary: The enantioselectivity in propargylic substitution reactions catalyzed by optically active thiolate-bridged diruthenium complexes was investigated using DFT calculations. Transition-state structures leading to the major (R) product were found to be more abundant than those leading to the minor (S) product, suggesting a higher probability of forming the major product. The introduction of a phenyl group in the thiolate ligand was proposed to enhance selectivity, leading to a novel transition state model for the asymmetric catalytic reaction system.
CHEMISTRY-AN ASIAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Hiroki Toda, Kaito Kuroki, Ryoichi Kanega, Shogo Kuriyama, Kazunari Nakajima, Yuichiro Himeda, Ken Sakata, Yoshiaki Nishibayashi
Summary: The study presents a manganese-catalyzed oxidative conversion of ammonia into dinitrogen, which can be conducted under chemical or electrochemical conditions. Under chemical conditions, up to 17.1 equivalents of N-2 per catalyst are generated, while under electrochemical conditions, the reaction proceeds with 96% faradaic efficiency to give up to 6.56 equivalents of N-2 per catalyst.
Article
Chemistry, Multidisciplinary
Shiyao Liu, Yoshiaki Tanabe, Shogo Kuriyama, Ken Sakata, Yoshiaki Nishibayashi
Summary: In this study, propargylic substitution reactions using ruthenium and copper catalysis with N-monosubstituted hydrazones as ambident nucleophiles were investigated. It was found that N-monosubstituted hydrazones exhibited different reactivities depending on the catalytic system, resulting in either propargylic alkylated or aminated products. DFT calculations were used to study the reaction pathways and further transformation of the products yielded multisubstituted pyrazoles in good to high yields.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Editorial Material
Chemistry, Multidisciplinary
Shiyao Liu, Yoshiaki Tanabe, Shogo Kuriyama, Ken Sakata, Yoshiaki Nishibayashi
Summary: The cover of this issue features the research on the propargylic substitution reaction of propargylic alcohol with an N-monosubstituted hydrazone, where the nucleophilicity of the hydrazone is controlled by the choice of catalytic system. The full article can be accessed at 10.1002/chem.202103287.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Ken Sakata, Yuuri Uehara, Shiona Kohara, Takeshi Yoshikawa, Yoshiaki Nishibayashi
Summary: In this study, the effects of propargylic substituents on the enantioselectivity and reactivity in propargylic substitution reactions were further investigated using density functional theory calculations. The results showed that substitution of a methyl group at the propargylic position could reverse the stereoselectivity, while substitution of a trifluoromethyl group for a methyl group was suggested to enhance the enantioselectivity.
Article
Chemistry, Organic
Takahiro Sawano, Masaki Ono, Ami Iwasa, Masaya Hayase, Juri Funatsuki, Ayumu Sugiyama, Eri Ishikawa, Takeshi Yoshikawa, Ken Sakata, Ryo Takeuchi
Summary: We report the branch-selective hydro-alkylation of simple alkenes using iridium catalysts. A variety of aliphatic and aromatic alkenes were suitable for this reaction, and the hydroalkylated products derived from malonic amides were suitable for further transformation. The reaction mechanism involves a reversible step followed by C-H reductive elimination.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Takeshi Yoshikawa, Yasuhiro Ikabata, Hiromi Nakai, Kentaro Ogawa, Ken Sakata
Summary: Conical intersections (CIs) play a crucial role in various photophysical, photochemical, and photobiological processes, but the systematic interpretation of minimum energy CI (MECI) geometries is unclear. A previous study investigated the MECI between the ground and first excited electronic states (S0/S1 MECI) using frozen orbital analysis (FZOA), identifying two controlling factors. However, one of the factors was found to be invalid for spin-flip TDDFT (SF-TDDFT). This study revisited the controlling factors using FZOA for the SF-TDDFT method and confirmed the control factors of S0/S1 MECI through numerical applications of a revised formula.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Multidisciplinary Sciences
Yulin Zhang, Yoshiaki Tanabe, Shogo Kuriyama, Ken Sakata, Yoshiaki Nishibayashi
Summary: Recently, transition metal-catalyzed enantioselective free radical substitution reactions have been recognized as convenient and important tools in synthetic chemistry. In this paper, we present a strategy to control enantioselective propargylic substitution reactions with alkyl radicals under photoredox conditions using a dual photoredox and diruthenium catalytic system. The successful example of transition metal-catalyzed enantioselective propargylic substitution reactions with free alkyl radicals is described.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Jonathan Z. Z. Shezaf, Catherine G. G. Santana, Connor Saludares, Edward S. S. Briceno, Ken Sakata, Michael J. J. Krische
Summary: The first correlation between metal-centered stereogenicity and regio-selectivity in a catalytic process is described. Alternate pseudo-diastereomeric chiral-at-ruthenium complexes of the type RuX(CO)[& eta;(3)-prenyl][(S)-SEGPHOS] form in a halide-dependent manner and display divergent regio-selectivity in catalytic C-C couplings of isoprene to alcohol proelectrophiles via hydrogen autotransfer. Control of metal-centered diastereo-selectivity has unlocked the first catalytically enantio-selective isoprene-mediated carbonyl tert-prenylations.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Manabu Hatano, Chiaki Nishioka, Ayaka Mimura, Risa Kimura, Yuki Okuda, Takeshi Yamada, Ken Sakata
Summary: This article describes a new type of catalyst that promotes a dehydrative esterification reaction between carboxylic acids and primary or secondary alcohols without the need to remove water. The reaction is conducted in toluene at 100 degrees C using a 2,2'-biphenol-derived phosphoric acid catalyst (2.5-10 mol%). The catalytic system is demonstrated to be useful for synthesizing pharmaceutically useful and acid-sensitive substrates.
Article
Chemistry, Multidisciplinary
Ken Sakata, Sarina Suzuki, Tsubasa Sugimoto, Takeshi Yoshikawa
Summary: The cycloaddition reaction between tropone and 1,1-diethoxyethene catalyzed by Lewis acid (LA) was studied using density functional theory (DFT) calculations. The presence of different Lewis acids (B(C6F5)3 or BPh3) led to different reaction pathways, favoring either [4 + 2] or [8 + 2] cycloaddition reactions, respectively. The nucleophilicity of the carbonyl O atom of tropone in the presence of LA was found to govern the selectivity of the reaction.
