Article
Chemistry, Applied
Yuan Chen, Rui Yu, Min Wang, Yanmin Huang, Yungui Peng
Summary: An asymmetric 1,6-conjugate addition reaction of dialkyl diazomethylphosphonates to para-quinone methides was developed using phase-transfer catalysis, yielding chiral diarylmethylated diazomethylphosphonates with high yields and enantioselectivities. The resulting products were further transformed into bioactive compounds with diarylmethine stereogenic centers.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Biochemistry & Molecular Biology
Yueteng Zhang, Peng Ji, Xiang Meng, Feng Gao, Fanxun Zeng, Wei Wang
Summary: A simple arylamine-catalyzed Mannich-cyclization cascade reaction was developed for facile synthesis of substituted 2H-benzo[h]chromenes, which involved the efficient generation of ortho-quinone methides (o-QMs) catalyzed by a simple aniline. The mild reaction conditions allowed for a broad spectrum of 1- and 2-naphthols and trans-cinnamaldehydes to engage in the cascade sequence with high efficiency.
Article
Biochemistry & Molecular Biology
Si-Jia Liu, Man-Su Tu, Kai-Yue Liu, Jia-Yi Chen, Shao-Fei Ni, Yu-Chen Zhang, Feng Shi
Summary: The catalytic asymmetric [2 + 4] cycloadditions of 3-vinylindoles with ortho-quinone methides using chiral phosphoric acid as the catalyst resulted in a series of indole-containing chroman derivatives with high structural diversity, overall high yields (up to 98%), good diastereoselectivities (up to 93:7 dr), and moderate to excellent enantioselectivities (up to 98% ee).
Article
Chemistry, Multidisciplinary
Esteban Matador, Javier Iglesias-Siguenza, David Monge, Pedro Merino, Rosario Fernandez, Jose M. Lassaletta
Summary: A highly enantio- and diastereoselective thiourea-catalyzed dearomatization of isoquinolines has been developed using N-tert-butylhydrazones as key neutral reagents, leading to the formation of appealing dihydroisoquinoline derivatives with excellent stereocontrol. Experimental and computational data support the generation of highly ordered complexes that play a crucial role in the selective and high-yielding transformations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Zaneta A. Mala, Mikolaj J. Janicki, Robert W. Gora, Krzysztof A. Konieczny, Rafal Kowalczyk
Summary: Dithiomalonates have been shown to be active nucleophiles in stereoselective additions, with Cinchona squaramides facilitating chirality transfer and mechanochemical approach proving to be effective.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Jing Cao, Antonia Seitz, Jose A. Forni, Anastasios Polyzos, David W. Lupton
Summary: This article reports on a reaction design that avoids the facile oxidation of phosphine organocatalyst and combines traditional nucleophilic phosphine organocatalysis with photoredox catalysis to enable Giese coupling with ynoates. The approach exhibits good generality, and its mechanism is supported by cyclic voltametric, Stern-Volmer quenching, and interception studies.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(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
Vasco Corti, Mathias Kirk Thaegersen, Valdemar Juel Enemaerke, Nomaan M. Rezayee, Casper L. Barlose, Karl Anker Jorgensen
Summary: The first atroposelective aminocatalytic methodology for the construction of C-N atropisomers is described. By directly coupling indole-2-carboxaldehydes to ortho-quinones, a new library of functionalized and enantioenriched C-N atropisomers was obtained using a designed and synthesized aminocatalyst. The synthetic utility of these atropisomers was demonstrated through various transformations.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Shiqi Jia, Yuhong Tian, Xin Li, Pengfei Wang, Yu Lan, Hailong Yan
Summary: A highly efficient method for atroposelective construction of nine-membered carbonate-bridged biaryls through vinylidene ortho-quinone methide (VQM) intermediates was demonstrated. Diverse products with desirable pharmacological features were synthesized in satisfying yields and good to excellent enantioselectivities. In subsequent bioassays, several compounds showed significant antiproliferative activity via the mitochondrial-related apoptosis mechanism. Further transformations generated more structural diversity and may inspire novel ideas for developing functional molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
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)
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, Physical
William R. R. Cassels, Evan T. T. Crawford, Jeffrey S. S. Johnson
Summary: We report a simple catalytic crystallization-driven enantio- and diastereoselective Mannich reaction for the synthesis of stereodefined alpha-monosubstituted-ss-ketoesters, dissymmetric ss-diesters, dissymmetric ss-diketones, and ss-keto amides. This method efficiently leverages product epimerization in solution. Mechanistic studies suggest that the initial enantioselective, diastereodivergent skeletal assembly is catalyzed by a chiral tertiary amine organocatalyst, followed by crystallization-induced diastereoconvergence to provide the challenging alpha-stereocenter in excellent stereoselectivity.
Article
Chemistry, Organic
Kangkana Chutia, Dhiraj Dutta, Manashi Sarmah, Pranjal Gogoi
Summary: A Pd-catalyzed cascade annulation process involving C-C bond formation and 1,6-conjugate addition for pi-extended benzofulvenes is described. The process is compatible with various functionalities of p-quinone methides and internal alkynes, resulting in diverse pi-extended benzofulvenes. Furthermore, this strategy can also be applied to aryne annulation with p-quinone methides.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Kyeong Seop Kim, Dae Young Kim
Summary: In this study, chiral 2-amino-4H-chromene derivatives were synthesized from 2-alkyl-substituted phenol derivatives via a one-pot cascade reaction using a binaphthyl-modified organocatalyst with low catalyst loading (1.25 mol%). The reaction showed moderate to high yields and excellent enantioselectivities.
SYNTHETIC COMMUNICATIONS
(2022)
Review
Chemistry, Physical
Mercedes Zurro, Aitor Maestro
Summary: This paper reviews the recent literature on the catalytic methodologies for the derivatization of aza-QM, including organocatalytic and organometallic approaches. The review analyzes various catalytic systems, involving chiral NHC carbenes, phosphoric acids, phosphoramidites, phosphine, copper, and palladium catalysis, showcasing their applicability for the synthesis of a diverse array of N-containing compounds, many of which exhibit biological activity.
Article
Chemistry, Organic
Victor Martin-Heras, Alejandro Parra, Mariola Tortosa
SYNTHESIS-STUTTGART
(2018)
Article
Chemistry, Multidisciplinary
Laura Amenos, Laura Trulli, Luis Novoa, Alejandro Parra, Mariola Tortosa
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2019)
Article
Chemistry, Physical
Laura Amenos, Luis Novoa, Laura Trulli, Ana Arroyo-Bondia, Alejandro Parra, Mariola Tortosa
Review
Chemistry, Multidisciplinary
Alejandro Parra
Article
Chemistry, Multidisciplinary
Luis Novoa, Laura Trulli, Alejandro Parra, Mariola Tortosa
Summary: The diastereo- and enantioselective diboration of spirocyclobutenes allows for the rapid preparation of a wide variety of chiral spirocyclic building blocks. The chemoselective functionalization of the carbon-boron bond in the products, including a stereospecific sp(3)-sp(2) Suzuki-Miyaura cross-coupling reaction, provides a powerful tool for controlling the directionality and nature of exit vectors in the spirocyclic framework.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Luis Novoa, Laura Trulli, Israel Fernandez, Alejandro Parra, Mariola Tortosa
Summary: In this study, a strategy for the synthesis of spirocyclic cyclobutanes with modulable exit vectors based on the regioselective monoborylation of spirocyclobutenes is presented. A wide variety of boryiated spirocycles have been prepared with complete regiocontrol using inexpensive copper salt and a commercially available bidentate phosphine. The boryl moiety serves as a synthetic handled for further functionalization, allowing access to a diverse array of spirocyclic building blocks from a common intermediate.
Article
Chemistry, Physical
Alma Viso, Roberto Fernandez de la Pradilla, Mariola Tortosa
Summary: Selective functionalization of the C-B bond in 1,2-bis(boronate) esters allows for the preparation of 1,2-difunctionalized compounds with stereocontrol, making them useful in the synthesis of complex molecules.
Article
Chemistry, Organic
Emily L. Vargas, Mario Franco, Ines Alonso, Mariola Tortosa, M. Belen Cid
Summary: B(2)nep efficiently promotes N-O cleavage of nitrones to form imines in high yields via a simple, efficient, sustainable, functional group tolerant, and scalable protocol. The reaction occurs in the absence of additives through a concerted mechanism. We showed that DMPO and TEMPO, typically used as radical traps, are also deoxygenated by diboron reagents, revealing their limitations as mechanistic probes.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Javier Teresa, Marina Velado, Roberto Fernandez de la Pradilla, Alma Viso, Blanca Lozano, Mariola Tortosa
Summary: In this work, the catalytic enantioselective cross-coupling of 1,2-bisboronic esters is described. Previous studies on group specific cross coupling have been limited to the use of geminal bis-boronates. This desymmetrization provides a novel approach for preparing enantioenriched cyclopropyl boronates with three contiguous stereocenters, which can be further derivatized through selective functionalization of the carbon-boron bond. Our results suggest that the enantiodetermining step of transmetallation occurs with retention of stereochemistry at carbon.
Article
Chemistry, Organic
Marina Velado, Manuel Martinovic, Ines Alonso, Mariola Tortosa, Roberto Fernandez de la Pradilla, Alma Viso
Summary: The base-induced [2,3]-sigmatropic rearrangement of enantiopure 2-sulfinyl dienes has been optimized using NaH and iPrOH. The reaction proceeds through allylic deprotonation and sulfoxide-sulfenate rearrangement. The presence of a terminal allylic alcohol is crucial for achieving complete regioselectivity and high enantioselectivities.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Applied
Carlos Jarava-Barrera, Alejandro Parra, Sergio Quesada, Sergio Orgaz-Gordillo, Roberto Fernandez de la Pradilla, Alma Viso, Javier Teresa, Ines Alonso, Mariola Tortosa
Summary: An array of enantioenriched vinyl boronates with an allylic carbonate moiety were prepared through selective hydroboration of propargyl carbonates. Treatment of these vinyl boronates with TBAF in THF resulted in the formation of enantioenriched 1,3-disubstituted allenes through a novel 1,2-anti elimination.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Mario Franco, Emily L. Vargas, Mariola Tortosa, M. Belen Cid
Summary: The study demonstrates that pyridine-boryl complexes can be utilized as super-electron donors to facilitate the coupling of thiols and aromatic halides via a S(RN)1 mechanism. The reaction shows high efficiency with a wide substrate scope, tolerating heterocycles and various functional groups, and has potential applications in drug synthesis and functionalized polythioethers.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Mario Franco, Raquel Sainz, Al Mokhtar Lamsabhi, Cristina Diaz, Mariola Tortosa, M. Belen Cid
Summary: This research investigates the application of carbon-based Cu(i) materials in borylation reactions of aliphatic and aromatic halides. The study reveals the previously understudied interactions between graphenic surfaces and Cu(i) salts, highlighting the enhancing effect of graphene on the reactivity of Cu2O metal against halide derivatives. The findings have practical implications for the development of efficient, general, scalable, and sustainable catalytic reactions.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
