Synthesis of selenated isochromenones by AgNO<sub>3</sub>-catalyzed three-component reaction of alkynylaryl esters, selenium powder and ArB(OH)<sub>2</sub>
We reported AgNO3-catalyzed three-component reaction of alkynylaryl esters, selenium powder and ArB(OH)2, providing an efficient synthetic route to selenated isochromenones.
Regioselective Synthesis of Isochromenones by Iron(III)/PhSeSePh-Mediated Cyclization of 2-Alkynylaryl Esters
作者:Adriane Sperança、Benhur Godoi、Simone Pinton、Davi F. Back、Paulo H. Menezes、Gilson Zeni
DOI:10.1021/jo201211s
日期:2011.8.19
A series of 4-Se-(Te, S)-isochromenones and 3-substituted isochromenones were synthesized in good yields via FeCl3-mediated cyclization of alkynylaryl esters with different diorganyl dichalcogenides. This methodology was carried out at room temperature, using inexpensive and environmentally friendly iron salts as metallic source and under air atmosphere. The reaction showed to be tolerant to a range of substituents bonded into the aromatic ring of the diorganyl dichalcogenides as well as to alkyl groups directly bonded to the chalcogen atom. Alternatively, the cyclization reaction of 2-alkynylaryl esters with FeCl3, in the absence of diorganyl dichalcogenide, gave the isochromenones without the chalcogen moiety in the structure. This approach proved to be highly regioselective, providing only six-membered ring products, once the possible five-membered products were not observed in any experiments.
Synthesis of 4-Selanyl- and 4-Tellanyl-1<i>H</i>-isochromen-1-ones Promoted by Diorganyl Dichalcogenides and Oxone
作者:Helen A. Goulart、José S. S. Neto、Angelita M. Barcellos、Krigor B. Silva、Maiara C. de Moraes、Raquel G. Jacob、Eder J. Lenardão、Thiago Barcellos、Gelson Perin
DOI:10.1021/acs.joc.1c00271
日期:2021.10.15
A new method was developed for the synthesis of 4-chalcogenyl-1H-isochromen-1-ones through the 6-endo-dig electrophilic cyclization of 2-alkynylaryl esters and diorganyl dichalcogenides under ultrasound irradiation. The reactions were performed under mild conditions, using Oxone as a green oxidant to promote the cleavage of the chalcogen–chalcogen bond in diorganyl diselenides and ditellurides to generate