Article
Chemistry, Physical
Youka Bunno, Yuta Tsukimawashi, Masahiro Kojima, Tatsuhiko Yoshino, Shigeki Matsunaga
Summary: Metal-containing Schiff base/sulfoxides were developed as chiral ligands for Pd(II)-catalyzed asymmetric intramolecular allylic C-H amination reactions, showing good performance in tuning the selectivity and reactivity of the Pd(II)-catalyst with high product yields.
Article
Chemistry, Organic
Chun-Tai Hung, Chun-Wei Lu, Shi-Han Huang, Yin-Feng Lu, Hsiang-Chi Chou, Cheng-Che Tsai
Summary: This research utilizes chiral sulfinamides as nucleophiles in intramolecular allylic substitution and sequential aerobic oxidation with aza-Michael addition reactions, achieving good yields of chiral isoindolines and high diastereoselectivities.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Takashi Mino, Yohei Fujisawa, Shizuki Yoshida, Mitsuru Hirama, Takumu Akiyama, Ryo Saito, Yasushi Yoshida, Yoshio Kasashima, Masami Sakamoto
Summary: By synthesizing cinnamoyl amide type chiral P,olefin ligand (S)-4, separable diastereomers of 4d were obtained successfully, and asymmetric allylic substitution reactions of indoles using (S,aS)-4d as a chiral ligand demonstrated high enantioselectivities (up to 98% ee).
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Aparna Tyagi, Naveen Yadav, Jabir Khan, Sankalan Mondal, Chinmoy Kumar Hazra
Summary: A mild, efficient, and metal-free synthetic protocol for the synthesis of beta-amino alcohols is reported. The reaction proceeds at room temperature with only 0.5 mol% catalyst loading and affords beta-amino alcohol derivatives in excellent yield. This protocol is well-tolerated by a wide range of styrene oxide and aniline derivatives. A notably efficacious gram-scale synthesis is also reported with a high TON = 842. Further, the Hammett correlation study was also performed to identify the rate-determining step.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Chemistry, Organic
Takashi Mino, Kaho Takaya, Kaito Koki, Natsume Akimoto, Yasushi Yoshida, Yoshio Kasashima, Masami Sakamoto
Summary: We synthesized N-alkyl-N-cinnamoyl amide type phosphine-olefin compounds 1 and observed axial chirality in the C(aryl)-N(amide) bond of compounds 1 using HPLC analysis with a chiral stationary phase column. Enantiomeric isomers of 1 were obtained and (-)-1 was demonstrated as a chiral ligand in Pd-catalyzed asymmetric allylic substitution reactions, leading to high enantioselectivity (up to 97% ee) in the esterification process.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Physical
Bing-ru Shao, Wen-feng Jiang, Chao Zheng, Lei Shi
Summary: The precise synthesis of axially chiral molecules is highly valuable in pharmaceutics, fine chemicals, and materials science. However, the enantioselective synthesis of non-atropisomeric axially chiral alkylidene cycloalkanes has been a great challenge due to the remote distance between chirality-related groups or atoms. We developed a general efficient methodology using palladium-catalyzed asymmetric allylic alkylation, which showed excellent enantioselectivities, high yields, and a wide substrate scope. The additive effect played a crucial role in improving the chem- and enantioselectivity of this reaction. Due to the value and structural diversity of the products, this method provides an opportunity for further exploration of the applied potential of axially chiral olefins in related research fields.
Article
Chemistry, Organic
Zhanglin Shi, Xiaolei Ji, Chaoren Shen, Kaiwu Dong
Summary: With the aid of an innate amide group, a Pd-catalyzed enantioselective hydroamidocarbonylation reaction of alpha-substituted acrylamides was developed, and a series of chiral 2-substituted succinimides were obtained in moderate to high yields and enantioselectivities. The generality of this approach was demonstrated by the carbonylation of both aryl- and alkyl-substituted acrylamides containing numerous functional groups.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Bin Feng, Yuan-Yuan Qin, Yaru Xie, Yonggang Li, Ge-Yun You
Summary: A simple selenide-phosphoramidite ligand was prepared in two steps with high yield under mild reaction condition. The activity of this ligand was examined in Pd-catalyzed asymmetric allylic alkylation reaction. The results showed that the ratio of ligand to metal played a key role in the reaction, and generally good yields and moderate enantioselectivities (up to 90% yield, 72% ee) were obtained under optimal reaction conditions.
Article
Chemistry, Multidisciplinary
Alexander Kremsmair, Henrik R. Wilke, Matthias M. Simon, Quirin Schmidt, Konstantin Karaghiosoff, Paul Knochel
Summary: A general method for preparing enantiomerically and diastereomerically enriched secondary alkylmagnesium reagents was reported, which were used for highly stereoselective electrophilic aminations to produce alpha-chiral amines with up to 97% ee. The reaction involved the formation of optically enriched secondary mixed alkylmagnesium species, which were then reacted with electrophiles to yield alpha-chiral tertiary alcohols, ketones, amides, phosphines, and tertiary amines with yields of up to 89% and ee values of up to 99% over three reaction steps.
Article
Chemistry, Multidisciplinary
Xin Yu, Lingfei Hu, Wolfgang Frey, Gang Lu, Rene Peters
Summary: Catalytic allylic substitution is an important method in asymmetric synthesis to generate C-C bonds with enantioselectivity. However, a common limitation is the formation of allylic substitution products with (E)-configured C=C double bonds. In this study, a planar chiral palladacycle catalyst was used to achieve a diastereospecific reaction outcome, maintaining the C=C double bond geometry of the allylic substrates in highly enantioenriched products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Ge-Yun You, Xiao-Feng Liu, Pei-Wen Fang, Lu-Fang Liang, Cheng-Hao Dai, Bin Feng
Summary: A study on the activity of chiral sulfinyl imine-thioether ligands in Pd-catalyzed asymmetric allylic alkylation reaction reveals the significant effect of the structure of sulfinamide motifs on the reaction yield and enantiomeric excess.
Article
Chemistry, Multidisciplinary
Hongfa Wang, Ruiyuan Zhang, Qinglong Zhang, Weiwei Zi
Summary: A new method for metal-hydride-catalyzed hydroalkylation of 1,3-dienes with aldehydes is described, providing access to chiral molecules with allylic stereocenters. By choosing a combination of chiral palladium and amine catalysts, highly diastereo- and enantioselective access to complementary diastereomers is achieved. The mechanism involves PdH formation and migratory insertion into the alkene, followed by C-C bond formation, with the origin of stereoselectivities investigated through distortion/interaction analysis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Tianjiao Cui, Chen-Xi Ye, Jordan Thelemann, Daniel Jenisch, Eric Meggers
Summary: Enantioselective or enantioconvergent iron-catalyzed ring-closing C(sp(3))-H aminations of N-aroyloxyurea through intermediate iron nitrene species provide chiral 2-imidazolidinones in high yield and with excellent enantioselectivity (up to 99% yield and 95% ee in 40 examples). This is a rare case of combining sustainable iron catalysis with C(sp(3))-H amination and asymmetric catalysis. Chiral 2-imidazolidinones are commonly found in bioactive molecules and can be hydrolyzed to valuable chiral vicinal diamines in a single step.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Physical
Li-Xia Liu, Wen-Jun Huang, Qing-Xian Xie, Bo Wu, Chang-Bin Yu, Yong-Gui Zhou
Summary: The research proposed a new strategy for dynamic kinetic resolution, successfully achieving enantioselective separation of flavonoid compounds and forming two stereogenic centers, providing a new way for organic synthesis.
Article
Chemistry, Applied
Madhawee K. Arachchi, Hien M. Nguyen
Summary: A broadly applicable methodology has been developed for the regio- and enantioselective construction of branched allylic carbon-heteroatom bonds from racemic, secondary allylic trichloroacetimidates. The products containing allylic C-O, C-N, and C-S bonds are obtained in synthetically useful yield and selectivity. Additionally, the chiral diene-ligated iridium catalyst is effective at promoting asymmetric aminations of acyclic secondary anilines.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Koki Matsumoto, Masaya Nakajima, Tetsuhiro Nemoto
JOURNAL OF ORGANIC CHEMISTRY
(2020)
Article
Chemistry, Organic
Haruka Homma, Shingo Harada, Tsubasa Ito, Ayaka Kanda, Tetsuhiro Nemoto
Article
Chemistry, Multidisciplinary
Tsubasa Ito, Shingo Harada, Haruka Homma, Hiroki Takenaka, Shumpei Hirose, Tetsuhiro Nemoto
Summary: This study developed a new method for achieving highly enantioselective dearomatization of chemically inert arenes, leading to the synthesis of polycycles with multiple stereogenic centers. Mechanistic investigations revealed the origin of chemo- and enantioselectivity in the reaction process.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Applied
Mai Yanagawa, Shingo Harada, Shumpei Hirose, Tetsuhiro Nemoto
Summary: The study developed a rhodium-catalyzed C-H functionalization reaction for synthesizing 2,3-fused indole variants using an alpha,beta-unsaturated enone as a directing group and electrophile. This annulation enabled the rapid assembly of valuable hydrocarbazolones from readily available indoles, and computational investigations were conducted to elucidate the reaction pathway and site-selectivity.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Jun Ueda, Shingo Harada, Mayu Kobayashi, Mai Yanagawa, Tetsuhiro Nemoto
Summary: A dual catalyst system consisting of maleic acid and Schreiner's thiourea was used to successfully synthesize a spiroindolenine core, providing a new approach for synthetic strategies that were previously difficult to achieve. Computational studies revealed a unique macrocyclic transition state that lowered the activation energy of the spirocyclization reaction.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Tsubasa Ito, Hiroki Takenaka, Haruka Homma, Shingo Harada, Tetsuhiro Nemoto
Summary: An asymmetric intramolecular cyclopropanation reaction under silver catalysis has been developed, producing enantioenriched gamma-lactam fused cyclopropane commonly found in bioactive molecules and pharmaceuticals. The fused cyclopropane was efficiently converted into drug candidate molecules in short steps, highlighting the utility of this method. Computational investigations based on density functional theory clarified the chemoselectivity between the desired cyclopropanation and overoxidation process observed experimentally.
TETRAHEDRON LETTERS
(2021)
Article
Chemistry, Organic
Takahito Kuribara, Masaya Nakajima, Tetsuhiro Nemoto
Summary: The article elucidates the selectivity difference between platinum and palladium in the Friedel-Crafts-type synthesis reaction, and reveals the mechanism of the behavioral differences of the two metals through density functional theory calculations and experimental studies.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Masaya Nakajima, Yusuke Adachi, Tetsuhiro Nemoto
Summary: This study demonstrated the potential of computational simulation-based natural product syntheses as an indispensable resource in the field of organic synthesis. The authors reported the asymmetric total syntheses of several resveratrol dimers based on a comprehensive computational simulation of their biosynthetic pathways.
NATURE COMMUNICATIONS
(2022)
Correction
Multidisciplinary Sciences
Masaya Nakajima, Yusuke Adachi, Tetsuhiro Nemoto
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Takahito Kuribara, Masaya Nakajima, Tetsuhiro Nemoto
Summary: Ligand design plays a crucial role in enhancing the performance of light-enabled catalytic processes. In this study, the authors synthesized a visible-light-activated secondary phosphine oxide ligand and applied it to Pd-catalyzed radical cross-coupling reactions. Through molecular design aided by computational calculations, the ligand enables ligand-to-Pd(II) and Pd(0)-to-ligand single-electron transfer under visible-light irradiation, facilitating radical cross-coupling reactions.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Dongil Choi, Noa Takahashi, Haruka Maruoka, Shingo Harada, Alina Nastke, Harald Groeger, Tetsuhiro Nemoto
Summary: We developed an enantioselective synthetic method utilizing Ir-catalyzed asymmetric hydrogenation to introduce chirality at the benzylic position, followed by Pd-catalyzed cascade cyclization for tricyclic molecular framework construction and Ag nitrene-mediated C-H amination for tetrasubstituted carbon center creation. This method provides access to a functionalized seven-membered ring-fused indole skeleton with a hydroxymethyl branch in the tetrasubstituted carbon.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Yoshinori Hashimoto, Shingo Harada, Ryosuke Kato, Kotaro Ikeda, Jannis Nonnhoff, Harald Groeger, Tetsuhiro Nemoto
Summary: This study reported a catalytic approach for the formal synthesis of more than 20 types of sarpagine/macroline alkaloids, with two key steps being the amide insertion reaction using cheap copper and biocatalytic asymmetric desymmetrization.
Article
Chemistry, Organic
Takahito Kuribara, Ayahito Kaneki, Yuma Mihara, Honoka Yuba, Tetsuhiro Nemoto
Summary: In this study, we describe a scandium-catalyzed regioselective synthesis of 5-carbonyl-4-hydroxybenzofurans via a phenol-directed intramolecular Friedel-Crafts reaction. This method was successfully applied for the total synthesis of furanoflavones. Experimental and theoretical calculations suggest that hydrogen bond interactions between the phenolic hydroxy group and the scandium complex enable regioselective intramolecular cyclization.
Article
Chemistry, Organic
Tetsuhiro Nemoto
Summary: This paper presents the advances in the synthesis of dragmacidin E, a bis-indole alkaloid isolated from a deep-water marine sponge in southern Australia. Synthetic studies conducted by the Funk, Feldman, Jia, and Nemoto groups are summarized, including the total synthesis of (±)-dragmacidin E achieved by Feldman et al. in 2011.
TETRAHEDRON LETTERS
(2023)
Article
Chemistry, Physical
Yu Matsuda, Masaya Nakajima, Tetsuhiro Nemoto
Summary: Transition metal-catalyzed photoreactions have been extensively reported, but the development of ligands for these reactions is limited. This study successfully synthesized acridine-containing PNP-pincer ligands and found that the platinum complex induced photoreactions of olefins under visible light irradiation. These reactions revealed unknown reactivities of transition metals that could not be achieved with existing well-known ligands.
