A Brønsted acid-catalyzed pinacol-type rearrangement pathway is reported here to synthesize various substituted α-(3-indolyl) ketones by employing unprotected indoles and α-hydroxy aldehydes as coupling partners. Utilization of economic and readily available Brønsted acid catalyst and use of simple starting precursors exemplify the economic viability of this method. Under this developed protocol, selective migration of aryl over alkyl or a second aryl group is observed depending upon the migratory aptitude of the substituents. Applicability of this method was further demonstrated by synthesizing highly substituted carbazoles through a simple extension of this method to one-pot cascade annulation strategy.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.joc.9b02474 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Peroxycarbenium-Mediated Asymmetric Synthesis of 1,2-Dioxanes and 1,2-Dioxolanes.
J Am Chem Soc
January 2025
BioCIS, Faculté de Pharmacie, Université Paris-Saclay, CNRS, Orsay 91400, France.
The endoperoxide scaffold is found in numerous natural products and synthetic substances of pharmaceutical interest. The main challenge to their synthetic access remains the preparation of chiral compounds due to the weakness of the peroxide bond, which limits the scope of available or applicable methods. Here, we demonstrate how peroxycarbenium species can be trapped by silylated nucleophiles with high enantioselectivities and diastereoselectivities when applicable, using a chiral imidophosphorimidate (IDPi) as a catalyst.
View Article and Find Full Text PDFScalable ultrasound-assisted synthesis of hydroxy imidazole -oxides and evaluation of their anti-proliferative activities; mechanistic insights into the deoximation of dioximes.
RSC Adv
January 2025
Department of Chemistry, University of North Bengal Raja Rammohunpur, Dist. Darjeeling 734013 India
The development of synthetic methodologies that promote greener reactions have become so essential that it has slowly shaped the way chemists think about the construction of physiologically and chemically active compounds. The acid-catalyzed iminoketone - aldehyde condensations leading to Hydroxy imidazole -oxides serve as robust strategies for forming C-N bonds. Considering all the existing challenges that come with the use of solvent and energy-intensive methodologies, herein a green synthetic strategy using ultrasound with optimization of reaction conditions and thorough investigation into the mechanism for obtaining the best yields are reported.
View Article and Find Full Text PDFBrønsted Acid-Catalyzed Regioselective Coupling between Azoles and Arylcyclobutenes.
Chem Asian J
January 2025
Northwest University, Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science,, 1 Xuefu Ave., Guodu Education and Hi-Tech Industries Zone,, Chang'an District, 710127, Xi'an, CHINA.
Herein, we describe a protocol for Brønsted acid-catalyzed regioselective coupling of azoles such as pyrazoles, 1,2,3-triazole, 1,3,4-triazole, benzotriazole, indazole and tetrazole, to cyclobutenes. These azoles could be directly coupled with various arylcyclobutenes with high site-selectivity, offering a distinct entry to more functionalized cyclobutanes. The usage of inexpensive TsOH•H2O catalyst, broad substrate scope, and open-air conditions make this protocol practically viable.
View Article and Find Full Text PDFSynthesis, Physicochemical Properties, and Ion Recognition Ability of Azulene-Based Bis-(Thio)Semicarbazone.
Molecules
December 2024
"C. D. Nenitzescu" Institute of Organic and Supramolecular Chemistry, Splaiul Independentei 202B, 060023 Bucharest, Romania.
Azulene-1,3-bis(semicarbazone), , and azulene-1,3-bis(thiosemicarbazone), , were synthesized by the acid-catalyzed condensation reactions of semicarbazide and thiosemicarbazide, respectively, with azulene-1,3-dicarboxaldehyde in stoichiometric amounts. Compounds and were identified by high-resolution mass spectrometry and characterized by IR, H-NMR, C-NMR, and UV-vis spectroscopic techniques. Crystal structure determination of azulene-1,3-bis(thiosemicarbazone) shows that the thiosemicarbazone units exhibit a -closed conformation, with both arms oriented in the same direction and adopting an configuration with respect to the imine linkages.
View Article and Find Full Text PDFLewis acid-catalyzed [2π+2σ] cycloaddition of dihydropyridines with bicyclobutanes.
Chem Commun (Camb)
January 2025
Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, 48149 Münster, Germany.
Herein we report a simple BF-catalyzed cycloaddition of dihydropyridines with bicyclobutanes for the expedient synthesis of novel three-dimensional azacycle-fused bicyclo[2.1.1]hexane scaffolds.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!