Article
Chemistry, Multidisciplinary
Peter-Yong Wang, Itai Massad, Ilan Marek
Summary: The facile and modular access to stereodefined disubstituted aldehyde-derived silyl enol ethers allowed for their successful application in a stereoselective aldol reaction, resulting in excellent yields and diastereomeric ratios. The counter-intuitive stereochemical behavior of this Mukaiyama-aldol reaction is explained by a non-classical open transition state.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Jinhu Wei, Jie-Sheng Huang, Chi-Ming Che
Summary: The chiral Fe-II(N4) complex developed is an effective chiral Lewis acid for the asymmetric conjugate addition of silyl enol ethers to alpha,beta-unsaturated 2-acyl imidazoles, resulting in high yields and enantioselectivities (up to 99% ee) of chiral 1,5-dicarbonyl synthons and cyclohexenone derivatives.
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
Jiaming Zou, Lei Xu, Yurong Tang, Wentao Wang, Yunfei Cai
Summary: The asymmetric synthesis of bridged tetrahydrobenzo[b]azepine and oxepine derivatives has been achieved through chiral Bri nsted acid catalyzed asymmetric aza-Piancatelli rearrangement/Michael addition sequence. The reaction proceeds under mild reaction conditions to afford the final bridged cyclic products in good yields with excellent enantio- and diastereoselectivities.
Article
Chemistry, Physical
Pablo J. Luggren, Liza A. Dosso, J. Isabe Di Cosimo
Summary: The feasibility of using Zn-Zr mixed oxides for gas-phase production of olefins from butyric acid was investigated. The composition of the catalyst and experimental conditions play a crucial role in determining the olefin yield.
APPLIED CATALYSIS A-GENERAL
(2022)
Article
Chemistry, Organic
Manman Sun, Jing Gui, Rong Zhong, Haijian Wu, Saimei Liu, Jinshan Li, Jianguo Yang, Zhiming Wang
Summary: A TfOH-catalyzed direct Michael addition and cascade cyclization reactions of azadienes with unactivated ketones have been developed, providing a divergent approach to 2,3-disubstituted benzofurans and benzofuro[3,2-b]pyridines. This method utilizes the weak nucleophilicity of unactivated ketones and controls the catalyst acidity as a key parameter. The use of commercial ketones and mild reaction conditions also offer synthetic and environmentally benign advantages.
Article
Chemistry, Multidisciplinary
Hui-Chao Ma, Ya-Nan Sun, Gong-Jun Chen, Yu-Bin Dong
Summary: This study reports a facile approach for the asymmetric intermolecular alpha-benzylation of aldehydes using a multifunctional chiral covalent framework catalyst. The reaction can effectively proceed under natural sunlight irradiation and shows broad generality.
Article
Chemistry, Organic
Subhomoy Das, Gaurav Goswami, Sandipan Halder, Manas K. Ghorai
Summary: Enolate mediated domino imino-aldol-aza-Michael and domino imino-aldol-aza-Michael-imino-aldol reactions have been developed for the diastereoselective synthesis of highly functionalized 2,6-disubstituted piperidines. The reaction mechanism involves an intermolecular imino-aldol reaction followed by an intramolecular aza-Michael reaction, depending on the presence of 1.0 or 2.0 equiv. of imine. The formation of piperidine derivatives is explained by plausible reaction mechanisms.
Article
Chemistry, Organic
Liam A. McLean, Allan J. B. Watson
Summary: An alternative synthesis of cycloalkyl-substituted CPA catalysts using Negishi coupling and Kumada coupling has been reported for improved yields and purity. The limitations of commercial organozinc reagents were identified and a robust procedure for their preparation was detailed. The route was demonstrated by preparing three different tri(cycloalkyl)aryl-substituted CPAs and their utility in asymmetric protonation reactions was shown.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Nikhil Srivastava, Hyun-Joon Ha
Summary: A straightforward and highly diastereoselective synthesis of beta-(aziridin-2-yl)-beta-hydroxy ketones was achieved via the Mukaiyama aldol reaction, with excellent yields and diastereoisomeric ratio. These ketones were further utilized in the synthesis of various alkaloids, demonstrating their versatile applications in organic synthesis.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Ganapathi Chary L. Nagunuri, Vidya Katangoor, Venkateshwarlu Surigilla, Eswaraiah Sajja, Thirumalai Rajan Srinivasan, Vijayavitthal T. Mathad
Summary: This article presents an efficient process for the preparation of chirally pure obeticholic acid with a high overall yield. The characterization of all possible diastereomers and the fate and control mechanism of related impurities are discussed in detail.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2022)
Article
Chemistry, Organic
Ryoga Hikawa, Mio Shimogaki, Taichi Kano
Summary: Novel threonine-derived amino sulfonamide organocatalysts were developed and successfully applied to asymmetric aldol reactions. The reactions produced anti-aldol adducts with high diastereo- and enantioselectivity when catalyzed by threonine-derived tosylamide, and syn-aldol adducts were obtained when using threonine-derived triflamide catalyst in reactions between alpha-siloxyacetone and aromatic aldehydes. In both cases, a significant improvement in diastereoselectivity was observed compared to threonine-derived carboxylic acid catalyst.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Review
Chemistry, Organic
Shuhui Li, Xiaoxuan Li, Hui Yao, Mengting Tan, Dan Xu, Nianyu Huang, Nengzhong Wang
Summary: Straight-chain omega-amino-alpha, beta-unsaturated carbonyl compounds are versatile organic synthons with important applications in organocatalysis. This review discusses the recent applications of these synthons in covalent catalysis, non-covalent catalysis, and bifunctional catalysis.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Review
Chemistry, Organic
Guillermo Caballero-Garcia, Jonathan M. Goodman
Summary: N-Triflylphosphoramides (NTPA) have emerged as popular catalysts for enantioselective transformations due to their stronger Bronsted acid properties compared to phosphoric acids (PA). This review categorizes NTPA-catalyzed reactions based on the enantio-determining step and highlights their use in total synthesis.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Alemayehu Gashaw Woldegiorgis, Zhao Han, Xufeng Lin
Summary: The highly regio-, diastereo-, and enantioselective dearomatization reaction of 1-substituted 2-naphthols and beta,gamma-alkynyl-alpha-imino esters with complete atom economy is disclosed via chiral phosphoric acid catalysis. This protocol provides facile and efficient access to asymmetric construction of axially chiral allene-derived naphthalenones bearing quaternary stereocenters in good yields with high diastereoselectivities and enantioselectivities.
Article
Chemistry, Organic
Jiye Jeon, Hyung Joo Kim, Cheol-Hong Cheon
JOURNAL OF ORGANIC CHEMISTRY
(2020)
Article
Chemistry, Organic
Young-In Jo, Chun-Young Lee, Cheol-Hong Cheon
Article
Chemistry, Organic
Young-In Jo, Chun-Young Lee, Cheol-Hong Cheon
JOURNAL OF ORGANIC CHEMISTRY
(2020)
Article
Chemistry, Organic
Hyung Joo Kim, Cheol-Hong Cheon
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2020)
Article
Chemistry, Analytical
Yeongseok Chae, Sein Min, Eunjoon Park, Chaiho Lim, Cheol-Hong Cheon, Keunhong Jeong, Kyungwon Kwak, Minhaeng Cho
Summary: The integration of flow cells with NMR and FTIR systems allows for real-time observation of reaction intermediates, offering a valuable tool for elucidating reaction mechanisms and obtaining elusive kinetic data. By combining the sensitivity of IR spectroscopy with the quantitative analysis capabilities of NMR, this approach enables comprehensive evaluation of reaction processes, including potentially hazardous reactions, without direct contact with harmful intermediates.
ANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Eunjoon Park, Jina Park, Cheol-Hong Cheon
Summary: This study discusses the distinct reactivity between cyanide and NHC with 4-(2-formylphenoxy) but-2-enoate derivatives.
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Eunjoon Park, Cheolwoo Bae, Cheon-Gyu Cho, Cheol-Hong Cheon
Summary: The total syntheses of the antirhine alkaloids were achieved through a series of reactions, including the cyanide-catalyzed imino-Stetter reaction and subsequent C-ring formation to generate the key intermediate. The trans-selective installation of the homoallylic alcohol side-chain at C-15 allowed the successful total syntheses of antirhine and its known epimer.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Jiye Jeon, Sang Eun Lee, Cheol-Hong Cheon
Summary: The total synthesis of (+/-)-hinckdentine A was achieved through a cyanide-catalyzed imino-Stetter reaction and oxidative rearrangement, followed by D-ring formation and seven-membered C-ring construction. The newly synthesized compound contains all functional groups correctly positioned in the natural product.
Article
Chemistry, Organic
Jinjae Park, Cheol-Hong Cheon
Summary: This study reports a concise total synthesis of rucaparib, an FDA-approved drug for ovarian and prostate cancers. The desired structure was achieved through key reactions, and the final compound was obtained with commercially available starting materials in a simple procedure, resulting in a high overall yield.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Sangmin Song, Seung-Hoon Um, Jaeho Park, Inho Ha, Jaehong Lee, Seongchan Kim, Hyojin Lee, Cheol-Hong Cheon, Seung Hwan Ko, Yu-Chan Kim, Hojeong Jeon
Summary: The study introduces a rapid synthesis method using a laser-induced hydrothermal process to synthesize hydroxyapatite particles ranging from nanometer to micrometer scale in seconds. This method allows selective metal ion substitution into the apatite matrix with controllable concentration. The synthesized powders show enhanced bone cell attachment and proliferation ability.
Article
Chemistry, Organic
Jiye Jeon, Cheol-Hong Cheon
Summary: In this paper, the first asymmetric total synthesis of iheyamine B from 2,2'-bisindoloazepinone is reported, which involves the stereoselective construction of the trans-vicinal 2-oxopropyl moiety in the azepine scaffold.
Article
Chemistry, Organic
Ju Hyeon Park, Jinjae Park, Cheol-Hong Cheon
Summary: A protocol for the synthesis of 2-(2-nitrophenyl)indoline-3-acetic acid derivatives was developed via base-catalyzed cyclization of N-(2-nitrobenzyl)-2-aminocinnamic acid derivatives. The synthetic utility of this methodology was illustrated by the concise synthesis of dihydropaullone, a partially saturated analog of paullone. Furthermore, the indoline scaffold could be further converted to the corresponding indoles and other indole-fused heterocycles.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Jinjae Park, Tae Lyn Kim, Cheol-Hong Cheon
Summary: In this paper, we discuss the recent progress made by our research group in the total synthesis of several 2,2'-biindolyl natural products using the cyanide-catalyzed imino-Stetter reaction. We describe a novel protocol for accessing 2,2'-bisindole-3-acetic acid derivatives via this reaction and the application of this method in the total synthesis of class I, class II, and class III 2,2'-biindolyl natural products.
Article
Chemistry, Multidisciplinary
Jinjae Park, Cheol-Hong Cheon
Summary: Two routes for the synthesis of rucaparib have been developed, using commercially available starting materials and the cyanide-catalyzed imino-Stetter reaction as the key step. The second-generation synthesis achieved a higher overall yield and resolved issues from the first-generation synthesis.
Article
Chemistry, Physical
Myeong-Geun Kim, Youngjo Choi, Eunjoon Park, Cheol-Hong Cheon, Nak-Kyoon Kim, Byoung Koun Min, Woong Kim
ACS APPLIED ENERGY MATERIALS
(2020)
Article
Chemistry, Organic
Geeta Devi Yadav, Pooja Chaudhary, Balaram Pani, Surendra Singh
Summary: Chiral transition metal complexes with privileged ligands are efficient catalysts for various asymmetric organic transformations. Transition metal complexes of C1-symmetric pyrrolidine-based ligands have been widely used in asymmetric organic reactions. However, a comprehensive review article on the transition metal complexes of chiral C1-symmetric pyrrolidine-based ligands derived from (L)-proline has not been published.
TETRAHEDRON LETTERS
(2024)