Alkyltelluro Substitution Improves the Radical-Trapping Capacity of Aromatic Amines
作者:Jia-fei Poon、Jiajie Yan、Vijay P. Singh、Paul J. Gates、Lars Engman
DOI:10.1002/chem.201602377
日期:2016.8.26
The synthesis of a variety of aromatic amines carrying an ortho‐alkyltelluro group is described. The new antioxidants quenched lipidperoxyl radicals much more efficiently than α‐tocopherol and were regenerable by aqueous‐phase N‐acetylcysteine in a two‐phase peroxidation system. The inhibition time for diaryl amine 9 b was four‐fold longer than recorded with α‐tocopherol. Thiol consumption in the aqueous
Novel Water-Soluble Diorganyl Tellurides with Thiol Peroxidase and Antioxidant Activity
作者:Takahiro Kanda、Lars Engman、Ian A. Cotgreave、Garth Powis
DOI:10.1021/jo990842k
日期:1999.10.1
at pH = 7.4 by using the coupled GSSG reductase assay. Dialkyl telluride 10 turned out to be the most efficient catalyst. Several alkylaryl tellurides 8 were also more efficient than any of the previously tested organotellurium compounds in this model. Bulky and electron-withdrawing aryl substituents seemed to reduce activity, whereas electron-donating groups enhanced it. Alkylaryl selenide 9 was
Iron (III)‐Promoted Synthesis of Substituted 4
<i>H</i>
‐Chalcogenochromenes and Chemoselective Functionalization
作者:Isadora M. de Oliveira、C. Henrique A. Esteves、Mariana P. Darbem、Daniel C. Pimenta、Julio Zukerman‐Schpector、Antonio G. Ferreira、Hélio A. Stefani、Flavia Manarin
DOI:10.1002/adsc.201900142
日期:2019.7.2
The iron(III)‐promoted synthesis of densely‐substituted 4H‐chalcogenchromene from organochalcogen propargylamines in the presence of diaryl dichalcogenides is reported. Subsequent C2‐functionalization with electrophiles and potassium trifluoroborate salts via Suzuki‐Miyaura coupling reaction are also presented. A plausible mechanism based on HRMS experiments is proposed and discussed.
Novel group transfer cyclization reactions of organotellurium compounds
作者:Lars Engman、Vijay Gupta
DOI:10.1039/c39950002515
日期:——
When irradiated in the presence of hexabutylditin, readily available O-allylated and O-prop-2-ynylated 2-hydroxyalkyl aryl tellurides undergo group transfer cyclization to afford 2, 4-disubstituted tetrahydrofuran derivatives.
Substituent Effects in Chain-Breaking Aryltellurophenol Antioxidants
作者:Jia-fei Poon、Jiajie Yan、Kjell Jorner、Henrik Ottosson、Carsten Donau、Vijay P. Singh、Paul J. Gates、Lars Engman
DOI:10.1002/chem.201704811
日期:2018.3.7
more efficiently than α‐tocopherol, with three to five‐fold longer inhibition times. Thus, these compounds offer better and longer‐lasting antioxidant protection than recently prepared alkyltellurophenols. Compounds with electron‐donating para substituents in the aryltelluro or phenolic part of the molecule showed the best results. The mechanism for quenching peroxyl radicals was considered and discussed