Review
Chemistry, Multidisciplinary
Fujie Tanaka
Summary: This article discusses catalysts and catalyst systems that use amino acids, primary, secondary, and/or tertiary amines as key catalytic functional groups to accelerate chemical transformations. It also explores strategies and methods that utilize amine derivatives as catalysts. The understanding of dynamics and kinetic controls in amine-catalyzed reactions has enabled the synthesis of complex molecules in stereocontrolled manners.
Article
Chemistry, Multidisciplinary
Avene C. Colgan, Rupert S. J. Proctor, David C. Gibson, Padon Chuentragool, Antti S. K. Lahdenpera, Kristaps Ermanis, Robert J. Phipps
Summary: This study reports a significant advancement in the catalytic enantioselective Minisci reaction, allowing the use of α-hydroxy radical coupling partners to obtain valuable enantioenriched secondary alcohol products. The approach is highly regioselective as well as highly enantioselective.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Francesco Vaghi, Giorgio Facchetti, Isabella Rimoldi, Matteo Bottiglieri, Alessandro Contini, Maria Luisa Gelmi, Raffaella Bucci
Summary: Multiple studies have shown that the pyrrolidine nucleus is more efficient as organocatalysts for the condensation of aldehydes with electrophiles via enamine, compared to piperidine or morpholine. The low reactivity of morpholine-enamines is due to the presence of oxygen on the ring and the pyramidalisation of nitrogen, which decreases the nucleophilicity of the enamine. Therefore, finding efficient morpholine organocatalysts is a challenging task.
FRONTIERS IN CHEMISTRY
(2023)
Article
Chemistry, Organic
Gen-Fa Wen, Rui Zhang, Chu-Yu Zhang, Chao-Shan Da
Summary: This study compares and explores the catalytic efficiencies of structurally similar alpha- and beta-amino acids in an asymmetric aldol transformation. The results show that both types of amino acids achieve high catalytic efficiencies under different optimal conditions, and in some cases, the beta-amino acid even exhibits higher enantioselectivity than the alpha-amino acid.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Hiromasa Ogawa, Hiroto Okawa, Keiji Mori
Summary: We investigated the effects of substituents on the aromatic rings in a diarylmethylamine unit, which we named the 'butterfly'-type amine unit, in an aminothiourea catalyst. The catalyst with a 3,5-bis(trifluoromethyl)phenyl group showed the best results, achieving excellent chemical yield and enantioselectivity in an asymmetric Michael reaction. Importantly, this catalyst demonstrated superior catalytic ability as a chiral catalyst compared to the well-known Takemoto catalyst, and this characteristic was observed in various asymmetric reactions.
Article
Chemistry, Multidisciplinary
Rosa Lopez, Claudio Palomo
Summary: N,N-Diacylaminals are flexible molecular scaffolds commonly used as amide surrogates in peptidomimetics. Recently, their singularity as an N-acyl imine equivalent and hydrogen-bond donor has led to new synthetic opportunities, particularly in the field of asymmetric catalysis. This concept article highlights the diverse synthetic potential of N,N-Diacylaminals and provides the necessary elements for further developments.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Hanbin Lu, Jiamin Lv, Canhua Zhou, Mi Zhou, Yanxiong Fang, Jinxiang Dong, Terumasa Kato, Yan Liu, Keiji Maruoka
Summary: In this study, a catalytic asymmetric direct Michael reaction of ketones with trans-beta-arylnitroethenes was successfully achieved under the influence of optically pure L-hydroxyproline-based secondary-amino aromatic Tf-amide organocatalyst. The addition of trialkylamine base additives, such as diethylmethylamine, played a crucial role in achieving high reactivity and enantioselectivity in this asymmetric Michael reaction.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Yue Jia, Zhihan Zhang, Guo-Ming Yu, Xuan Jiang, Liang-Qiu Lu, Wen-Jing Xiao
Summary: A visible light induced enantioselective deaminative arylation of amino acid derivatives by bifunctional copper catalysis is disclosed. A variety of alpha-aryl-N-phenylamides are prepared with good efficiency and high enantioselectivity. Experimental investigations and theoretical calculations reveal the crucial role of additional phenols in improving catalytic efficiency and enantiocontrol.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Applied
Jen-Yu Kuan, I-Ting Chen, Hsuan Lin, Jeng-Liang Han
Summary: We have developed a substrate-dependent, regio- and stereocontrolled diversity-oriented organocatalytic vinylogous Michael addition/cyclization cascade of 2-alkylidene indane-1,3-diones with enals, using secondary amines as the catalyst. This method allows for the selective synthesis of spiroindane-1,3-diones, tetrahydrofluoren-9-one derivatives, and benzofused oxabicyclo[3.3.1]nonanes. Plausible catalytic pathways have been proposed, and DFT calculations have clarified the mechanisms involved.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Review
Chemistry, Multidisciplinary
Corinne Coutant, Paul De Bonfils, Pierrick Nun, Vincent Coeffard
Summary: The advent of asymmetric organocatalysis has revolutionized the way chemists create or break chemical bonds, enabling new strategies for enantioselective functionalization. This success is attributed to various activation modes and the availability of numerous chiral organic catalysts. Selective functionalization of compounds with multiple activation sites, such as cyclohexanone-derived dienones, has also contributed to breakthroughs in this field. These compounds can undergo diverse transformations and offer new opportunities for natural product synthesis. This review focuses on intermolecular functionalization of (cross)-conjugated cyclohexanone-derived compounds using asymmetric organocatalysis.
Article
Chemistry, Applied
Irma Garcia-Monzon, Jorge Borges-Gonzalez, Tomas Martin
Summary: The heterogenization of homogeneous catalysts onto a solid support is a crucial step towards sustainable chemistry. In this study, we developed a series of polymer-supported tetrahydropyran-based hybrid dipeptides as active catalysts for the enantioselective Michael addition of aldehydes to beta-nitrostyrenes. The optimal anchor position and orientation between the catalyst and solid support, as well as the linker length, were carefully designed to enhance the catalytic efficiency. These supported catalysts exhibited high yields and enantiomeric excesses, and detailed deactivation studies provided important insights for prolonging their useful life.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Muhammad Sohail, Fujie Tanaka
Summary: The DYKAT reactions can transform dihydrobenzofuranone derivatives into spirooxindole derivatives with high enantioselectivities and yields, regardless of the stereochemistry of the starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Organic
Wei Wen, Qi-Xiang Guo
Summary: This article summarizes the recent advances in the application of chiral aldehyde catalysis in asymmetric reactions and prospects its future development.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Multidisciplinary
Bo-Bo Gou, Yue Tang, Yan-Hong Lin, Le Yu, Qing-Song Jian, Huai-Ri Sun, Jie Chen, Ling Zhou
Summary: A new type of chiral all-carbon tetrasubstituted VQMs was successfully prepared via nucleophilic addition of 2-alkynylnaphthols to o-quinone methides or imines, catalyzed by chiral phosphoric acids. The method showed high efficiency and excellent diastereoselectivities and enantioselectivities, leading to the synthesis of naphthyl-2H-chromenes with axially and centrally chiral elements and axially chiral quinone-naphthols. The obtained axially chiral naphthols could further be converted into valuable phosphine ligands and other functional molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Bastian Jakob, Andreas M. Diehl, Kathrin Horst, Harald Kelm, Georg Manolikakes
Summary: Here we report a palladium-catalyzed asymmetric three-component synthesis of α-arylglycine derivatives. This operationally simple method utilizes glyoxylic acid, sulfonamides, and arylboronic acids as starting materials to obtain α-arylglycine scaffold in good yields and enantioselectivities. The synthesized products can be directly used as building blocks in peptide synthesis.
FRONTIERS IN CHEMISTRY
(2023)
Article
Chemistry, Medicinal
Elvira Hermawati, Suzany D. Ellita, Lia D. Juliawaty, Euis H. Hakim, Yana M. Syah, Hayato Ishikawa
Summary: Two new quinone derivatives isolated from an endophytic fungus from Morus cathayana showed potential as tyrosine kinase inhibitors, displaying particularly strong inhibitory properties against Bruton's Tyrosine Kinase.
JOURNAL OF NATURAL MEDICINES
(2021)
Article
Biotechnology & Applied Microbiology
Syuuto Toyoda, Morihiro Oota, Hayato Ishikawa, Shinichiro Sawa
Summary: The research discovered that some commercial silica gels containing calcium sulfate can attract nematodes, which may be used in agriculture to reduce the prevalence of root-knot nematodes.
PLANT BIOTECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Jukiya Sakamoto, Hayato Ishikawa
Summary: This study reports a series of bioinspired transformations that convert strictosidine aglycones into monoterpenoid indole alkaloids. By removing a silyl protecting group and conducting selective conversions, various monoterpenoid indole alkaloids can be synthesized efficiently.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Shinya Shiomi, Kaewsri Wilailak, Wataru Soutome, Hiromitsu Takayama, Mariko Kitajima, Hayato Ishikawa
Summary: A first asymmetric total synthesis of huperzine H has been achieved in a 12% overall yield from commercially available (+)-pulegone. The relative and absolute stereochemistry of huperzine H is established through key reactions including a highly diastereoselective Mukaiyama-Michael addition reaction and an intramolecular S(N)2 cyclization reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Kazuki Urakawa, Yurie Yatsuoka, Yuta Kawabata, Hyuma Masu, Masaki Matsuda, Hayato Ishikawa
Summary: Borocyclic radicals with highly conjugated aromatics were generated from orthoquinone-containing polycyclic aromatic compounds by trapping the photoinduced triplet state. The stable picene-based borocyclic radical exhibited a unique crystal structure and higher electrical conductivity.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Editorial Material
Chemistry, Organic
Hayato Ishikawa
JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN
(2022)
Article
Nutrition & Dietetics
Mario A. Tan, Hayato Ishikawa, Seong Soo A. An
Summary: The study found that extracts from Pandanus amaryllifolius have potential anti-Alzheimer's disease effects by inhibiting A beta aggregation, reducing oxidative stress, and reversing mitochondrial damage.
Article
Chemistry, Multidisciplinary
Jukiya Sakamoto, Mariko Kitajima, Hayato Ishikawa
Summary: The total syntheses of geissoschizine-type monoterpenoid indole alkaloids (MTIAs) were achieved using various methods such as intramolecular Pictet-Spengler cyclization and aza-Michael cyclization/E1cB elimination/stereoselective olefin isomerization sequence. The synthesis of (+)-villocarine A and (-)-apogeissoschizine were successfully accomplished, and (+)-geissoschizine was obtained through ring-opening from apogeissoschizine.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Akiho Yoshidome, Jukiya Sakamoto, Mizuki Kohara, Shinya Shiomi, Mako Hokaguchi, Yuki Hitora, Mariko Kitajima, Sachiko Tsukamoto, Hayato Ishikawa
Summary: Divergent total syntheses of hetero-oligomeric iridoid glycosides were achieved using efficient synthetic methods. The monomer unit loganin was stereoselectively synthesized through reductive cyclization of secologanin. Sequential condensation reactions of derivatives of loganin and secologanin led to the synthesis of heterooligomers cantleyoside, (E)-aldosecologa-nin, dipsaperine, (3R, 5S)-5-carboxyvincosidic acid 22-loganin ester, and dipsanoside A.
Article
Plant Sciences
Morihiro Oota, Syuuto Toyoda, Toshihisa Kotake, Naoki Wada, Masatsugu Hashiguchi, Ryo Akashi, Hayato Ishikawa, Bruno Favery, Allen Yi-Lun Tsai, Shinichiro Sawa
Summary: A chemoattractant of plant-parasitic root-knot nematodes has been isolated from the Super-growing Root culture system and found to be enriched in carbohydrates, particularly arabinose and galactose. This attractant is essential for the attraction of Meloidogyne incognita but not other nematode species.
FRONTIERS IN PLANT SCIENCE
(2023)
Article
Chemistry, Organic
Yuta Nakashima, Taichi Inoshita, Mariko Kitajima, Hayato Ishikawa
Summary: The first asymmetric total synthesis of the Lycopodium alkaloid senepodine F, containing a decahydroquinoline ring (AB-ring) and a quinolizidine ring (CD-ring) connected by a methylene tether, has been achieved. The key steps of this synthesis involve an organocatalytic asymmetric Diels-Alder reaction, a diastereoselective intramolecular aza-Michael reaction, and an intramolecular SN2 cyclization to construct nitrogen-containing heterocycles. Furthermore, this total synthesis allowed for the reassignment of the stereochemistry of the decahydroquinoline ring in senepodine F.
Article
Chemistry, Organic
Jukiya Sakamoto, Hayato Ishikawa
Summary: The preparation of natural product libraries by total synthesis is an important and attractive research topic in organic chemistry. This Account presents a practical total synthesis of secologanin using an asymmetric organocatalytic cascade reaction. It also describes the collective total synthesis of secologanin-related natural products using reference to biosynthesis. So far, 39 secologanin-related natural products have been successfully synthesized using bioinspired strategies, with the synthetic strategies for 20 of them presented in this Account.
Article
Chemistry, Organic
Jukiya Sakamoto, Daiki Hiruma, Mariko Kitajima, Hayato Ishikawa
Summary: In this study, the collective and efficient asymmetric total syntheses of five beta-carboline-type monoterpenoid indole alkaloid glycosides were successfully achieved in fewer than thirteen steps. The beta-carboline motif was efficiently constructed through a Pictet-Spengler reaction with alpha-cyanotryptamine, followed by the removal of the cyano group and autoxidation (aromatization). Furthermore, bioinspired reactions were developed to provide different alkaloid skeletons.
Article
Chemistry, Medicinal
Jukiya Sakamoto, Mariko Kitajima, Hayato Ishikawa
Summary: In this study, the total syntheses of several alkaloids from Mitragyna speciosa were successfully achieved using organocatalytic reactions and bioinspired transformations. These alkaloids exhibit potent biological activity with analgesic properties.
CHEMICAL & PHARMACEUTICAL BULLETIN
(2022)
Article
Chemistry, Medicinal
Nanako Nakashima, Jukiya Sakamoto, Kenta Rakumitsu, Mariko Kitajima, Lia Dewi Juliawaty, Hayato Ishikawa
Summary: A new pentacyclic monoterpenoid indole alkaloid glycoside named secorubenine (1) was isolated from the heartwood of Adina rubescens collected in Indonesia. Its structure was elucidated through spectroscopic analysis and chemical modification, followed by a bioinspired enantioselective total synthesis achieved in 12 steps. The structure and absolute stereochemistry of the compound were confirmed during synthesis.
CHEMICAL & PHARMACEUTICAL BULLETIN
(2022)