This report describes the synthesis of organoselenyl isoquinolinium imides through a tandem cyclization between N'-(2-alkynylbenzylidene)hydrazides and diselenides. The reaction was carried out at room temperature under an ambient atmosphere using cheap iron(iii) chloride as the metallic source. The strategy shows good tolerance to a broad range of N'-(2-alkynylbenzylidene)hydrazides and diselenides, and forms C-N and C-Se bonds in one step. The obtained product is further transformed into a bioactive H-pyrazolo[5,1-a]isoquinoline skeleton easily via a silver catalyzed [3 + 2] cycloaddition.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/d0ob01517b | DOI Listing |
J Org Chem
October 2022
Laboratório de Síntese, Reatividade, Avaliação Farmacológica e Toxicológica de Organocalcogênios CCNE, UFSM, Santa Maria, Rio Grande do Sul 97105-900, Brazil.
Base-promoted cyclization of 3-organoselenyl-methylene-2-alkynyl aryl propargyl ethers has been developed for the synthesis of 3-butylselanyl-methylene benzofurans, 3-methyl-2-alkynyl-benzofurans, and 4-iodo-benzo[]furan-fused selenopyrans. Under potassium -butoxide as the base and tetrahydrofuran as the solvent, at room temperature, 3-organoselenyl-methylene-2-alkynyl aryl propargyl ethers were converted into 3-butylselanyl-methylene benzofurans via a 5--dig mode. Using the same substrate, changing the solvent to dimethylsulfoxide, 3-methyl-2-alkynyl-benzofurans were selectively obtained in good yields.
View Article and Find Full Text PDFJ Org Chem
October 2022
Laboratório de Síntese, Reatividade, Avaliação Farmacológica e Toxicológica de Organocalcogênios CCNE, UFSM, Santa Maria, Rio Grande do Sul 97105-900, Brazil.
This study describes the reaction of 2-amino arylalkynyl ketones with organoselenolates to form ()-vinyl selenides, which lead to 4-organoselenyl quinolines via an intramolecular condensation. Using the optimized reaction conditions, the generality of this cyclization was studied with various arylalkynyl ketones and diorganyl diselenides. The study of the reaction mechanisms led to the isolation and identification of a vinyl selenide, which was the key intermediate for this cyclization.
View Article and Find Full Text PDFOrg Biomol Chem
June 2022
Laboratorio de Sintese, Reatividade, Avaliaçao Farmacologica e Toxicologica de Organocalcogenios, CCNE, UFSM, Santa Maria, Rio Grande do Sul, 97105-900, Brasil.
Organoselenyl iodide promoted the intramolecular nucleophilic cyclization of -alkynyl ethylcarbamates in the synthesis of 4-(organoselenyl) oxazolones. The reaction was regioselective, giving the five-membered oxazolone products as the unique regioisomer an initial activation of the carbon-carbon triple bond through a seleniranium intermediate, followed by an intramolecular 5- cyclization mode. The generality of the methodology has been proven by applying the optimized reaction conditions to different organoselenyl iodides and -alkynyl ethylcarbamates having different substituents directly bonded to the nitrogen atom and in the terminal position of the alkyne.
View Article and Find Full Text PDFOrg Biomol Chem
October 2020
Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science & Collaborative Innovation Centre of Suzhou Nano Science and Technology, Soochow University, 199 Ren-Ai Road, Suzhou, Jiangsu 215123, China.
This report describes the synthesis of organoselenyl isoquinolinium imides through a tandem cyclization between N'-(2-alkynylbenzylidene)hydrazides and diselenides. The reaction was carried out at room temperature under an ambient atmosphere using cheap iron(iii) chloride as the metallic source. The strategy shows good tolerance to a broad range of N'-(2-alkynylbenzylidene)hydrazides and diselenides, and forms C-N and C-Se bonds in one step.
View Article and Find Full Text PDFOrg Biomol Chem
May 2020
Laboratorio de Sintese, Reatividade, Avaliaçao Farmacologica e Toxicologica de Organocalcogenios, CCNE, UFSM, Santa Maria, Rio Grande do Sul 97105-900, Brasil.
This paper describes a selenium-promoted electrophilic cyclization of arylpropiolamides allowing the synthesis of 3-organoselenyl spiro[4,5]trienones via a 5-endo-dig ipso-mode. The 3-organoselenyl-quinolinone derivative formation via 6-endo-dig was avoided using an electrophilic organoselenium species in a metal-free protocol. The use of phenylselenyl bromide (1.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!