Article
Chemistry, Multidisciplinary
Danijel Glavac, Matija Gredicak
Summary: This study describes the synthesis of enantioenriched Betti base precursors containing a congested quaternary stereocenter. In a chiral phosphoric acid-catalyzed reaction, a series of in situ generated isoindolinone-derived ketimines and phenol derivatives yield products with good to excellent yields and moderate enantioselectivities. Conversion of the obtained products into chiral Betti bases while retaining optical purity is demonstrated.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Organic
Hui Liu, Yingkun Yan, Min Li, Xiaomei Zhang
Summary: By utilizing chiral phosphoric acid as a catalyst, enantioselective aza-Friedel-Crafts reaction between 5-aminoisoxazoles and isatin-derived N-Boc ketimines was achieved, yielding novel 3-isoxazole 3-amino-oxindoles with high yields and moderate to good enantioselectivities. One product's absolute configuration was determined by X-ray crystal structural analysis, and a plausible reaction mechanism was proposed, followed by a successful scale-up reaction. Additionally, the product underwent Suzuki-Miyaura coupling with phenylboronic acid, resulting in moderate yield without affecting the enantioselectivity.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Arben Berisa, Danijel Glavac, Chao Zheng, Shu-Li You, Matija Gredicak
Summary: An efficient enantioselective formal Betti reaction was described between phenols and diaryl ketimines generated in situ from isoindolinone alcohols. Catalyzed by a chiral phosphoric acid, a wide range of ketimines and phenols yielded isoindolinone derivatives with a congested quaternary stereogenic center bearing three aryl groups in high yields, regioselectivities, and enantioselectivities.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Review
Chemistry, Applied
Gabriele Lupidi, Alessandro Palmieri, Marino Petrini
Summary: N-Activated ketimines are characterized by electron-withdrawing groups linked to the nitrogen atom, enhancing the electrophilic character and allowing addition reactions with weak nucleophiles. The presence of oxygen atoms in these groups is crucial for asymmetric catalytic reactions. This review summarizes the literature on the synthesis of optically active alpha-substituted amino derivatives using open-chain N-activated ketimines.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Yunlong Zhao, Rou Xiao, Weibin Fang, Junling Zhao
Summary: This study presents a protocol for the highly selective addition reaction of isatin-derived beta,gamma-unsaturated alpha-ketoesters with 4-aminoindoles at the C7 position. The reaction, catalyzed by a SPINOL-derived chiral phosphoric acid, yields bisindole derivatives with up to 97% enantiomeric excess. Further biological testing revealed that the products have high cytotoxicity against various cancer cell lines.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Ran Chen, Qian-Qian Yan, Shao-Jun Hu, Xiao-Qing Guo, Li-Xuan Cai, Dan-Ni Yan, Li-Peng Zhou, Qing-Fu Sun
Summary: By varying the metal/ligand ratio, dinuclear triple helicates or mononuclear pincer complexes can be selectively obtained from the same chiral bis-tridentate ligand, with both complexes demonstrating catalytic properties in asymmetric Friedel-Crafts alkylation reactions due to the presence of open metal sites.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Biochemistry & Molecular Biology
Mohammad Shahidul Islam, Abdullah Saleh Alammari, Assem Barakat, Saeed Alshahrani, Matti Haukka, Abdullah Mohammed Al-Majid
Summary: Five new C-2-symmetric chiral ligands were synthesized from enantiopure amino alcohols, and used for Friedel-Crafts asymmetric alkylation. The bis(oxazolinyl)thiophene ligands showed higher efficiency in inducing asymmetric alkylation compared to bis(imidazolinyl)thiophene analogues.
Article
Chemistry, Multidisciplinary
Yuki Saito, Shu Kobayashi
Summary: The article discusses the application of chiral heterogeneous Sc catalysts in continuous-flow reactions, achieving efficient synthesis of compounds through noncovalent interactions and the crucial role of heteropoly acid.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Yuanyuan Zhang, Yaoyu Liang, Xiaodan Zhao
Summary: The enantioselective electrophilic three-component thioarylation of alkenes using chiral selenide catalysis with free phenols as arylating sources has been disclosed. Various chiral phenols were obtained in high regio-, enantio-, and diastereoselectivities. Mechanistic studies showed that the transformation proceeded through carbon nucleophilic attack to give the products rather than the intramolecular rearrangement of phenolic ether intermediates.
Article
Chemistry, Organic
Mei Duan, Jingchao Chen, Ting Wang, Shaojian Luo, Meifen Wang, Baomin Fan
Summary: A wide range of chiral 3-amino-2-oxindoles were successfully synthesized with high optical purities through the enantioselective Friedel-Crafts addition of naphthols with isatin-derived ketimines using H8-BINOL-derived chiral biaryl phosphoric acid as the catalyst.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Yaowen Liu, Martin C. Dietl, Robin Heckershoff, Chunyu Han, Hongwei Shi, Matthias Rudolph, Frank Rominger, Isabella Caligiuri, Kanwal Asif, Muhammad Adeel, Thomas Scattolin, A. Stephen K. Hashmi
Summary: Due to its excellent bioactivity profile, spirooxindole is widely used in pharmaceutical and synthetic chemistry. In this study, we developed an efficient method for the synthesis of highly functionalized spirooxindolocarbamates via a gold-catalyzed cycloaddition reaction. This protocol is compatible with various functional groups, uses readily available starting materials, and exhibits good antiproliferative activity on human tumor cell lines.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Mu Hongwen, Wu Hao, Gao Yingying, Jin Ying, Wang Liming
Summary: In this study, Cinchona alkaloid derivatives were used to catalyze the Friedel-Crafts reaction of hydroxylindoles with isatins, resulting in high yields and excellent regio- and enantioselectivities.
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE
(2022)
Article
Chemistry, Physical
Ying-Pong Lam, Jingxian Huang, Xiaojian Jiang, Ying-Yeung Yeung
Summary: A class of cinchona alkaloid-derived zwitterions has been successfully used to achieve highly enantioselective Steglich rearrangement and the same catalytic protocol was found applicable in the asymmetric aldol reaction. Studies were conducted to elucidate a clearer mechanism.
Article
Biochemistry & Molecular Biology
Marta Gil-Ordonez, Camille Aubry, Cristopher Nino, Alicia Maestro, Jose M. Andres
Summary: A series of N-Boc ketimines derived from pyrazolin-5-ones have been successfully used as electrophiles in enantioselective Mannich reactions with different 1,3-dicarbonyl compounds. The reaction enables the synthesis of 4-amino-5-pyrazolone derivatives with diverse structures, including the beta-diketone and pyrazolinone substructures. The use of a quinine-derived bifunctional squaramide as an organocatalyst with a very low loading proves to be highly effective in terms of yield and enantioselectivity. The obtained products can be further transformed into enantioenriched diheterocyclic systems, which show potential as drug candidates.
Review
Chemistry, Organic
Anup Biswas
Summary: The aza-Friedel-Crafts reaction allows for the efficient coupling of electron-rich aromatic systems with imines, facilitating the incorporation of aminoalkyl groups into the aromatic ring. This reaction offers a wide range of forming aza-stereocenters, which can be controlled by different asymmetric catalysts. This review highlights recent advances in asymmetric aza-Friedel-Crafts reactions mediated by organocatalysts and provides mechanistic insights into the origin of stereoselectivity.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Amparo Sanz-Marco, Daniel Esperilla, Marc Montesinos-Magraner, Carlos Vila, M. Carmen Munoz, Jose R. Pedro, Gonzalo Blay
Summary: A Cu(ii)/BOX complex catalyst was used for the enantioselective addition of difluorinated silyl enol ethers to acylpyridine N-oxides. The reaction produced difluorinated chiral tertiary alcohols, which are of great interest in medicinal chemistry. The reaction had good to excellent yields and high enantioselectivities. The stereochemical outcome of the reaction was explained by DFT calculations.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Miguel Gavara-Edo, Francisco Javier Valverde-Munoz, Rosa Cordoba, M. Carmen Munoz, Javier Herrero-Martin, Jose Antonio Real, Eugenio Coronado
Summary: In this study, three new neutral Fe(II) SCO molecules belonging to the {Fe[H2B(pz)(2)](2)(L)} family were synthesized, and their crystallographic structure and magnetic properties were investigated. These compounds exhibited thermal- and light-induced SCO transitions with different degrees of cooperativity and effectiveness. Furthermore, two of the compounds were demonstrated to be sublimable, forming homogeneous thin films that retained the chemical integrity of the original molecules. SCO/2D horizontal hybrid devices based on CVD-graphene were successfully produced using these films, enabling the detection of the thermal SCO transition through the electric properties of CVD-graphene.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Inorganic & Nuclear
Alejandro Orellana-Silla, Ruben Turo-Cortes, Victor Rubio-Gimenez, Carlos Bartual-Murgui, Rob Ameloot, Carlos Marti-Gastaldo, M. Carmen Munoz, Jose Antonio Real
Summary: This study investigates the influence of chemical functionalization on the magnetic and adsorption properties of porous Fe-II coordination polymers. The results show that the chemical functionalization leads to significant changes in the magnetic transition temperature and curve shape, as well as higher adsorption capacities. The structural reasons behind these variations are determined through single crystal-to-single crystal transformations.
INORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Applied
Laura Carceller-Ferrer, Gonzalo Blay, M. Carmen Munoz, Jose R. Pedro, Carlos Vila
Summary: A diastereo- and enantioselective synthesis of spirocyclopropylpyrazolones was achieved through a Michael/alkylation cascade reaction of 4-arylidenepyrazol-5-ones with diethyl 2-bromomalonate catalyzed by (DHQ)(2)AQN. The corresponding spirocyclic compounds were obtained selectively with yields of 30-83%, diastereoselectivities ranging from 60:40 to >95:5, and enantiomeric excess of 26-93% under mild reaction conditions.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Physical
Jaume Rostoll-Berenguer, Gonzalo Blay, Jose R. Pedro, Carlos Vila
Summary: Financial support is acknowledged from grant PID2020-116944GB funded by MCIN/AEI/10.13039/501100011033, and by ERDF A way of making Europe and CIAICO/2021/147 funded by Conselleria d'Innovacio, Universitat, Ciencia i Societat Digital. J.R.-B. thanks the Ministerio de Ciencia, Innovacion y Universidades for a FPU predoctoral contract (FPU17/00688). C.V. thanks the RyC contract (RYC-2016-20187) funded by MCIN/AEI/10.13039/501100011033 and by European Union NextGeneration EU/PRTR. Access to NMR, MS, and X-ray facilities from the Servei Central de Suport a la Investigacio Experimental (SCSIE)-UV is also acknowledged.
Article
Chemistry, Multidisciplinary
Jaume Rostoll-Berenguer, Victor Garcia-Garcia, Gonzalo Blay, Jose R. Pedro, Carlos Vila
Summary: This study describes an organophotoredox 1,6-radical addition of 3,4-dihidroquinoxalin-2-ones to para-quinone methides catalyzed by Fukuzumi's photocatalyst under the irradiation of a HP Single LED (455 nm). The corresponding 1,1-diaryl compounds bearing a dihydroquinoxalin-2-one moiety (20 examples) were obtained with good to excellent yields under mild reaction conditions. Several experiments were carried out to propose a reaction mechanism.
ACS ORGANIC & INORGANIC AU
(2023)
Article
Chemistry, Multidisciplinary
Borja Ortin-Rubio, Jaume Rostoll-Berenguer, Carlos Vila, Davide M. Proserpio, Vincent Guillerm, Judith Juanhuix, Inhar Imaz, Daniel Maspoch
Summary: In this study, a generalized net-clipping approach is proposed for predicting the topology of metal-organic frameworks (MOFs) constructed from less-symmetric ligands. The approach generates less-symmetric nets with less-connected linkers through the deconstruction of more-symmetric and more-connected linkers in edge-transitive nets. The researchers successfully applied this approach to different types of linkers, resulting in several new derived and clipped nets. The feasibility of using net-clipping to predict clipped nets is supported by literature examples and new experimental additions, demonstrating the significance of this method in the rational design of new reticular materials.
Article
Chemistry, Organic
Ricardo Toran, Eduardo Portillo, Amparo Sanz-Marco, Carlos Vila, Gonzalo Blay
Summary: We report the enantioselective arylation of isoxazolin-5-ones using a bifunctional squaramide derived from Cinchona alkaloid as a catalyst. The reaction proceeds with high yields and excellent enantioselectivities, resulting in isoxazolin-5-ones featuring an arylated quaternary stereocenter. This study represents the first application of o-QDIs as arylating reagents in asymmetric catalysis.
ORGANIC CHEMISTRY FRONTIERS
(2023)
