Article
Chemistry, Multidisciplinary
Wei Liu, Tianren Qin, Wansen Xie, Jinmiao Zhou, Zidan Ye, Xiaoyu Yang
Summary: We have developed an efficient modular asymmetric synthesis of azahelicenes from readily available polycyclic aromatic amines, aldehydes, and (di)enamides, employing a central-to-helical chirality conversion strategy. A series of aza[5]- and aza[4]helicenes bearing various substituents were easily obtained with good yields and high enantioselectivities. The diverse derivatizations and the preliminary application of the azahelicene derivative as a chiral organocatalyst demonstrated the potential of this method, and the photophysical and chiroptical properties of these azahelicenes were well studied, showing potential applications in novel organic optoelectronic materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yunrong Chen, Chaofan Zhu, Zheng Guo, Wei Liu, Xiaoyu Yang
Summary: The first kinetic resolution of hydroquinoline derivatives with alpha,alpha-disubstitution has been achieved through asymmetric remote aminations with azodicarboxylates enabled by chiral phosphoric acid catalysis. Mechanistic studies suggest a monomeric catalyst pathway proceeding through rate- and enantio-determining electrophilic attack promoted by a network of attractive non-covalent interactions between the substrate and catalyst. Facile subsequent removal and transformations of the newly introduced hydrazine moiety enable these protocols to serve as powerful tools for asymmetric synthesis of N-heterocycles with alpha,alpha-disubstitution.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Organic
Natalia M. Moreira, Lorena S. R. Martelli, Arlene G. Correa
Summary: This review discusses the advances in asymmetric organocatalyzed synthesis of coumarin derivatives, focusing on the catalyst activation mode, providing important references for the development of efficient and greener synthetic methods.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Applied
Eugenia Marques-Lopez, Isaac G. Sonsona, Miryam Garces-Marin, M. Concepcion Gimeno, Raquel P. Herrera
Summary: In this study, the potential of phosphites as nucleophiles for the asymmetric synthesis of chiral chromene derivatives was explored. By employing asymmetric organocatalyzed phospha-Michael addition, chiral chromenylphosphonates were synthesized using a bifunctional squaramide. The optimized protocol provided good reactivity with yields of up to 95% and chiral products with an enantiomeric excess of up to 98%.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Review
Chemistry, Multidisciplinary
Nomaan M. Rezayee, Johannes N. Lamhauge, Karl Anker Jorgensen
Summary: The concept of umpolung has revolutionized synthetic chemistry by allowing the formation of novel connections among functional groups. Recent developments in α-functionalizations of aldehydes have advanced the field by providing new strategies for constructing tetrasubstituted tertiary stereocenters. These reactions are highly modular and offer complete stereocontrol, making them promising in cross-disciplinary applications.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Multidisciplinary Sciences
Chengwen Li, Ying-Bo Shao, Xi Gao, Zhiyuan Ren, Chenhao Guo, Meng Li, Xin Li
Summary: We have synthesized enantioenriched 1-(3-indol)-quino[n]helicenes through chiral phosphoric acid-catalyzed Povarov reaction followed by oxidative aromatization. The method has a broad substrate scope and offers rapid access to a wide range of chiral quinohelicenes with high enantioselectivities up to 99%. Additionally, we have explored the photochemical and electrochemical properties of selected quinohelicenes.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Applied
Jing Xue, Meng Wang, Qian Zhao, You-Cheng Wang, Qian-Qian Yang, Bo Han
Summary: An asymmetric synthesis of a series of tricycle-fused dispirooxindoles frameworks via multicomponent cascade 1,3-dipolar cycloadditions has been disclosed. The reaction showed high yield and good enantioselectivity, and the resulting compounds can be further transformed into other spirooxindole structures.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Zhi-Hong Du, Meng Yuan, Bao-Xiu Tao, Wen-Juan Qin, Xiang-Ming Liang, Yu-Yan Li, Hang Lin, Lian-Chun Zhang, Chao-Shan Da
Summary: This study demonstrates that a tert-leucine-derived organocatalyst can efficiently catalyze the asymmetric cross-aldol reaction of glyoxylate and alkyl aldehydes at room temperature with high yield and enantioselectivity. The tert-leucine with a large side group is essential for the high enantioselectivity. Additionally, the reaction shows potential for the eco-friendly chemical production of the pharmaceutical intermediate (R)-pantolactone with high yield and enantiopurity.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Chemistry, Organic
Zorana Ferjancic, Radomir N. Saicic
Summary: The combination of organocatalytic aldol reaction and reductive amination allows for rapid, stereoselective synthesis of N-heterocycles, which is of great significance for the synthesis of iminosugars and other polyhydroxylated alkaloids.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
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, Organic
Yousra Hamdane, Pradeep S. Chauhan, Suresh Vutla, Mukandila Mulumba, Huy Ong, William D. Lubell
Summary: Fifteen N-aminoimidazolone (Nai) dipeptides with different 5-position side-chain groups were synthesized through regioselective proline-catalyzed reactions and acid-mediated dehydration. Introducing 5-aryl-Nai dipeptides into CD36 receptor peptide ligands provided insights into the conformation responsible for binding affinity and anti-inflammatory activity.
Article
Chemistry, Organic
Ajay Sharma, Satyendra Kumar Pandey
Summary: An efficient and concise organocatalyzed protecting-group free synthetic approach is described for synthesizing the stereoisomers of the antidepressant drug reboxetine. The synthesis involves organocatalytic Jorgensen asymmetric epoxidation, epoxide migration, and Mitsunobu inversion as key steps.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Ken Okuno, Yasuaki Furuya, Seiji Shirakawa
Summary: The kinetic resolution of racemic compounds is a reliable method to prepare chiral molecules in highly optically enriched forms. However, the kinetic resolution of racemic carboxylic acids has not been well developed. Esterification and lactonization promoted by chiral organocatalysts have been found to be effective methods for the kinetic resolution of chiral carboxylic acids.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Applied
Claire Segovia, Jeremy Godemert, Jean-Francois Briere, Vincent Levacher, Sylvain Oudeyer
Summary: An organocatalyzed one-pot sequential deracemization of aromatic ketones with a stereogenic center at the alpha-position was achieved through an acid-base strategy, in which enantioselective protonation reaction played a key role. This protocol provides enantioenriched ketones with up to 89% ee without isolating sensitive intermediates like silyl enolates. Water was found to be crucial in this process. This one-pot sequence serves as a valuable extension to previously reported chemically driven red-ox protocols, expanding the range of molecules eligible for deracemization.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Johannes N. Lamhauge, David A. McLeod, Casper L. Barlose, Gwyndaf A. Oliver, Laura Viborg, Tobias Warburg, Karl Anker Jorgensen
Summary: This article reports a method for the synthesis of tropane derivatives using (5+2) cycloaddition reactions, with excellent stereo selectivity and yield. The mechanism and conditions of this reaction were determined through a series of experiments.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Biochemistry & Molecular Biology
Claudio Parra, Patricio Munoz, Luis Bustos, Felipe Parra, Mario J. Simirgiotis, Hugo Escobar
Summary: The study identified the phenolic composition of Origanum vulgare extract from the Andean region of the Atacama Desert, and evaluated its antimicrobial, antioxidant, and inhibitory activities. The oregano extract exhibited high antioxidant and antibacterial properties, suggesting potential use in managing chronic diseases.
Article
Biochemistry & Molecular Biology
Gabriel Vargas-Arana, Claudia Merino-Zegarra, Marcos Riquelme-Penaherrera, Luis Nonato-Ramirez, Henry Delgado-Wong, Mariano Walter Pertino, Claudio Parra, Mario J. Simirgiotis
Summary: Cocona fruits are popular food and medicinal fruits in South America, with high nutritional and antioxidant values that help lower cholesterol and triglyceride levels, preventing atherosclerosis.
Article
Biochemistry & Molecular Biology
Carmen Cortes, Diego A. Gonzalez-Cabrera, Ruth Barrientos, Claudio Parra, Javier Romero-Parra, Mariano Walter Pertino, Carlos Areche, Beatriz Sepulveda, Jorge Borquez, Alfredo Torres-Benitez, Mario J. Simirgiotis
Summary: In this study, the chemical composition and biological activity of Ovidia pillopillo, an endemic species of the Valdivian Forest in Chile, were investigated for the first time. The plant was found to contain various flavonoids and coumarins, and exhibited strong antioxidant and enzyme inhibition activities. These findings suggest that Ovidia pillopillo has potential as a source of new medicines.
Article
Food Science & Technology
Patricio Munoz, Felipe Parra, Mario J. Simirgiotis, German F. Sepulveda Chavera, Claudio Parra
Summary: The study revealed that Physalis peruviana L. fruits grown in arid conditions in the Andean region have higher nutritional and bioactive properties, with rich content of trace elements and bioactive compounds, as well as high levels of predominant phenolic compounds that exhibit antioxidant and antimicrobial activity. Additionally, it was found to inhibit α-amylase activity, suggesting its potential use in managing chronic diseases such as diabetes.
Article
Chemistry, Organic
Claudia Marques, Faiza Diaba, Enrique Gomez-Bengoa, Josep Bonjoch
Summary: A synthetic approach to functionalized ABC-tricyclic framework of calyciphilline A-type alkaloids is reported, which involves radical cyclization and stereocontrolled aldol cyclization. The resulting compound serves as a building block for this class of alkaloids, and the synthesis of azatricyclic compound I constitutes a formal synthesis of himalensine A.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Luis Bustos, Carlos Echiburu-Chau, Alejandro Castro-Alvarez, Ben Bradshaw, Mario J. Simirgiotis, Marco Mellado, Claudio Parra, Mauricio Cuellar
Summary: This study determined the cytotoxicity of eleven chalcones synthesized from two acetophenones and investigated their possible mechanisms. Two chalcones showed significant inhibitory effects and are potential candidates for further research and development.
Article
Chemistry, Organic
Laura G. Rodriguez, Ana Delgado, Carlos J. Ciudad, Veronique Noe, Josep Bonjoch, Ben Bradshaw
Summary: A two-step reaction was developed to synthesize a ring system found in natural products. The reaction was explored with eight substituted nitrobenzenes, achieving yields of up to 87%. One of the benzazocine compounds, 4h, exhibited high cytotoxicity and was active against eight cancer cell lines.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Medicinal
Maximiliano Martinez-Cifuentes, Emmanuel Soto-Tapia, Camila Linares-Pipon, Ben Bradshaw, Paulina Valenzuela-Hormazabal, David Ramirez, Patricio Munoz-Torres, Claudio Parra
Summary: This study proposes the design of beta-keto esters as antibacterial compounds. By synthesizing eight beta-keto ester analogues and conducting computational analysis, compound 8 was found to have the most promising potential. In vitro antimicrobial screening showed that compounds 6 and 8 exhibited the most promising activity against the panel of bacteria studied.
Meeting Abstract
Cardiac & Cardiovascular Systems
Bernardita Gonzalez, Pilar Munoz, Claudio Parra, Catherine Bravo
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
(2023)
Article
Medicine, General & Internal
Bruno Dighero, Fernando J. Verdugo, Hugo Fuentes, Matias Herrera, Jorge Sandoval, Cecilia Munoz, Christian Dauvergne, Yenny Ortega, Claudio Parra, Gonzalo Torres
Summary: Chronic coronary syndromes in young women are rare and often have slower progression of atherosclerotic coronary artery disease, leading to atypical clinical presentations and less diagnostic investigation. Non-atherosclerotic causes should be considered in young women with angina. This case report describes a 25-year-old woman diagnosed with aortitis and bilateral coronary ostial stenosis secondary to Takayasu's arteritis, who initially responded to medical therapy but eventually required percutaneous coronary intervention due to persistent ischemia.
REVISTA MEDICA DE CHILE
(2022)
Article
Chemistry, Organic
Claudia Marques, Faiza Diaba, Jaume Roca, Josep Bonjoch
Summary: The 5-endo-trig radical cyclization of N-benzyl-N-[(2-substituted)cycloalkenyl] trichloroacetamides using Bu3SnH and AIBN provides access to 3a-methyl- and 3a-methoxycarbonyl enelactams. Diastereoselective enolate alkylation of these enelactams leads to the synthesis of a set of 3-substituted derivatives, which can be further reduced to generate polyfunctionalized cis-octahydroindoles containing three consecutive stereocenters at C-3, C-3a, and C-7a. These building blocks can also be synthesized through an initial reductive radical cyclization using (carbo-substituted)dichloroacetamides.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Agronomy
Luis Bustos Gonzalez, Mario Juan Simirgiotis, Claudio Parra, Susana Alfaro-Lira, Emilio Soto, Carlos Echiburu-Chau
Summary: This research investigated the inhibitory effects of highland herbs in northern Chile on multiple cancer cell lines, identifying 5 extracts with strong activity worth further evaluation. It is part of a systematic effort to find new candidates for cancer therapies.
