Article
Chemistry, Organic
Timothy J. Paris, Chris Schwartz, Rachel Willand-Charnley
Summary: The successful synthesis and isolation of heteroaryl ketene acetals were achieved through intermolecular transfer of alkoxyl from electrophilic peroxides to lithiated benzofurans, indoles, and pyridines, showing enhanced reactivity towards electrophilic oxygen. The stability of the heteroaryl ketene acetals throughout purification techniques was superior, possibly due to increased aromaticity of the indole and pyridine structures. The reported products demonstrated resilience to workup and flash column chromatography procedures, overcoming typical issues associated with alkyl ketene acetal synthesis.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Zhuqing Liu, Jiang Lou, Jiaqi Xiao
Summary: A TBAI/K2S2O8-promoted [4 + 2] annulation of ketene N,S-acetals, and N-tosylhydrazones was efficiently developed, enabling straightforward access to a variety of trisubstituted pyridazines in reasonable to good yields. The synthetic methodology features a broad substrate scope and a good functional group tolerance. Control experiments demonstrated the indispensability of the alkylthio functionality in the enaminone substrates.
Review
Chemistry, Multidisciplinary
Lukas Biesen, Thomas J. J. Muller
Summary: Aroyl-S,N-ketene acetals are a unique class of heterocyclic dyes with tunable solid-state emission and aggregation-induced emission properties. They can be synthesized using various methods and can be further expanded into systems with multiple chromophores.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Ravuri Srinath, Arindam Manna, Subhankar Shee, Vijay Babu Pathi, Saswati Ghosh, Krishnendu Khamaru, Nakul Chandra Maiti, Biswadip Banerji
Summary: A one-pot protocol for synthesizing tetracyclic triazole-piperazine-quinazolinone-fused N-heterocyclic scaffolds is reported, utilizing tandem click and cross-dehydrogentive coupling reactions with high atom economy. The method is highly functional group tolerable and has a broad substrate scope, with some derivatives showing strong white solid-state fluorescence.
Article
Chemistry, Multidisciplinary
Lukas Biesen, Yannic Hartmann, Thomas J. J. Mueller
Summary: Symmetric and unsymmetric diaroyl-S,N-ketene acetals can be easily synthesized in good yields by utilizing the nucleophilic character of the methine position. The resulting aroyl compounds exhibit tunable emission properties and increased stability of luminescent aggregates.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Haifeng Yu, Xue Zhang, Liangliang Li, Hui Luo, Guangbo Che
Summary: A novel and efficient method using K2CO3 as a catalyst has been developed for the amidation of carboxylic acids with alpha-oxo ketene-N,S-acetals. The reaction proceeds in the presence of 10 mol% of K2CO3 and readily available (E)-4-(alkylamino)-4-(ethylthio)but-3-en-2-ones as amine surrogates. This method represents the first example of C-N bond cleavage of alpha-oxo ketene-N,S-acetals, and a proposed mechanism suggests the key role of the base in the transformation.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Ganesh Kumar, Subhasish Ray, Gaurav Shukla, Maya Shankar Singh
Summary: A one-pot synthesis of bench-stable quinoxaline N-oxides was achieved using a-oxoketene N,S-acetals and tert-butyl nitrite in open air. The double functionalization of N,S-acetals proceeds via an unexpected (Csp(2))-H nitrosation by NO radical and subsequent intramolecular N-arylation leading to quinoxaline, which is then oxidized to quinoxaline N-oxides. This protocol offers short reaction time, good functional group tolerance, and mild conditions without the need for a catalyst or external additive.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Multidisciplinary
Lukas Biesen, Lars May, Nithiya Nirmalananthan-Budau, Katrin Hoffmann, Ute Resch-Genger, Thomas J. J. Mueller
Summary: Aroyl-S,N-ketene acetal-based bichromophores can be synthesized efficiently in a consecutive three-component synthesis, yielding a library of 31 bichromophoric fluorophores with tunable emission properties through substitution pattern adjustment. Varying both chromophores enables different communication pathways between them, offering potential applications in fluorescence switches from alcoholic beverages analysis to pH sensors.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Review
Chemistry, Organic
Shuyan Yu, Zeyu Liu, Hongbing Lan, Kun Qian, Xiaohua Ding, Zhigang Yin
Summary: This mini-review provides a summary of the synthetic progress of fused bicyclic N,O-acetals. Different reaction types, including hetero-Diels-Alder cycloaddition, step-by-step reactions, [3+2] cycloaddition, and other novel strategies, are elaborated. The catalytic systems and reaction mechanisms are also described in detail.
CURRENT ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Miquel Navarro, Alexis Tabey, Gyorgy Szaloki, Sonia Mallet-Ladeira, Didier Bourissou
Summary: The oxidation of Au(I) complexes with two hemilabile ligands resulted in the stabilization of Au(III) complexes through chelation by phosphine-amine (P^N) and mesoionic N-heterocyclic carbene-pyridine (C^N) ligands. The structures of all complexes were confirmed by NMR spectroscopy and X-ray diffraction analyses.
Article
Chemistry, Inorganic & Nuclear
Jacopo Segato, Walter Baratta, Paola Belanzoni, Leonardo Belpassi, Alessandro Del Zotto, Daniele Zuccaccia
Summary: The study showed that the activity of NHC-Au-X catalysts in the cycloisomerization of N-(prop-2-yn-yl)benzamide is related to the basic strength of the anion, with performance decreasing gradually with increasing basicity and hydrogen-bond acceptor power of X-. The characteristics of the solvent and counterion should both be taken into account in considering the reaction.
INORGANICA CHIMICA ACTA
(2021)
Article
Chemistry, Multidisciplinary
Lukas Biesen, Dennis Woschko, Christoph Janiak, Thomas J. J. Mueller
Summary: Aroyl-S,N-ketene acetals are a highly diverse class of aggregation-induced emission fluorogens with a plethora of interesting properties. The interplay of substituents allows control over their emission color, intensity, and quantum yields both in solids and in the aggregated state.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Applied
Ming Bao, Xiongda Xie, Wenhao Hu, Xinfang Xu
Summary: A gold-catalyzed carbocyclization/C=N bond formation cascade reaction has been developed for the synthesis of polyfunctionalized 4-iminonaphthalenones and indenes in good to high yields under mild reaction conditions. The resulting products could be converted into multi-substituted 2-naphthol derivatives in high yields.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Physical
Lukas Biesen, Thomas J. J. Mueller
Summary: Donor-substituted aroyl-S,N-ketene acetals were rapidly synthesized by nucleophilic attack and decarbonylation, followed by addition-elimination reaction. These compounds exhibited intensive solid-state emission and pronounced aggregation-induced emission (AIE) characteristics with high quantum yields. By changing the base, enlarged aroyl-S,N-ketene acetal bi- and trichromophores were easily accessible.
Article
Chemistry, Multidisciplinary
Lijun Shi, Mingshan Wen, Fuwei Li
Summary: The study reports a selective method for the synthesis of fused N-heterocycles through palladium-catalyzed tandem reactions, which successfully addresses the selectivity issue in the presence of incompatible step reactions and effectively prevents side reactions.
CHINESE JOURNAL OF CHEMISTRY
(2021)
