CFÔéâ-Bis-TEMPO-Vis: new visible light active bis-benzimidazolequinone alkoxyamine

Patrick Kielty; Pau Farràs; Dennis A. Smith; Fawaz Aldabbagh

doi:10.3390/m1300

CFÔéâ-Bis-TEMPO-Vis: new visible light active bis-benzimidazolequinone alkoxyamine

Patrick Kielty
, Pau Farràs
, Dennis A. Smith
, Fawaz Aldabbagh

Research output: Contribution to journal › Article › peer-review

Abstract

Alkoxyamines of TEMPO usually dissociate thermally at >100 °C; however, room temperature homolysis, activated by visible light, occurs with benzimidazolequinone derivatives. 1,1'-Dimethyl-2,2'-bis{[(2,2,6,6-tetramethylpiperidin-1-yl)oxy]methyl}-6-(trifluoromethyl)-1H,1'H-[5,5'-bibenzimidazole]-4,4',7,7'-tetrone (CFÔéâ-Bis-TEMPO-Vis) is prepared in a 59% yield through NBS/HÔééSOÔéä oxidative demethylations of the dimethoxybenzimidazole-benzimidazolequinone precursor with aqueous work up. The alternative basic work up in air gave the epoxide derivative of CFÔéâ-Bis-TEMPO-Vis. Unlike the latter CFÔéâ-epoxide, both alkoxyamine residues are labile under green light (470-600 nm), and the rate of TEMPO release is three times slower than Bis-TEMPO-Vis.

Original language	English
Article number	M1300
Journal	MolBank
Volume	2021
Issue number	4
Early online date	26 Nov 2021
DOIs	https://doi.org/10.3390/m1300
Publication status	Published - 31 Dec 2021

Bibliographical note

Note: This work was supported by the Irish Research Council; awarding P.K. an Enterprise Partnership Scholarship.

Keywords

Chemistry
epoxide
homolysis
kinetics
nitroxide
quinones
radicals

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10.3390/m1300

Aldabbagh-F-50677-VoRFinal published version, 2.08 MBLicence: CC BY

https://doi.org/10.3390/M1300

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@article{5fee153231284014a12f3df248d846c3,

title = "CF{\^O}{\'e}{\^a}-Bis-TEMPO-Vis: new visible light active bis-benzimidazolequinone alkoxyamine",

abstract = "Alkoxyamines of TEMPO usually dissociate thermally at >100 °C; however, room temperature homolysis, activated by visible light, occurs with benzimidazolequinone derivatives. 1,1'-Dimethyl-2,2'-bis\{[(2,2,6,6-tetramethylpiperidin-1-yl)oxy]methyl\}-6-(trifluoromethyl)-1H,1'H-[5,5'-bibenzimidazole]-4,4',7,7'-tetrone (CF{\^O}{\'e}{\^a}-Bis-TEMPO-Vis) is prepared in a 59\% yield through NBS/H{\^O}{\'e}{\'e}SO{\^O}{\'e}{\"a} oxidative demethylations of the dimethoxybenzimidazole-benzimidazolequinone precursor with aqueous work up. The alternative basic work up in air gave the epoxide derivative of CF{\^O}{\'e}{\^a}-Bis-TEMPO-Vis. Unlike the latter CF{\^O}{\'e}{\^a}-epoxide, both alkoxyamine residues are labile under green light (470-600 nm), and the rate of TEMPO release is three times slower than Bis-TEMPO-Vis.",

keywords = "Chemistry, epoxide, homolysis, kinetics, nitroxide, quinones, radicals",

author = "Patrick Kielty and Pau Farr{\`a}s and Smith, \{Dennis A.\} and Fawaz Aldabbagh",

note = "Note: This work was supported by the Irish Research Council; awarding P.K. an Enterprise Partnership Scholarship.",

year = "2021",

month = dec,

day = "31",

doi = "10.3390/m1300",

language = "English",

volume = "2021",

journal = "MolBank",

issn = "1422-8599",

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TY - JOUR

T1 - CFÔéâ-Bis-TEMPO-Vis

T2 - new visible light active bis-benzimidazolequinone alkoxyamine

AU - Kielty, Patrick

AU - Farràs, Pau

AU - Smith, Dennis A.

AU - Aldabbagh, Fawaz

N1 - Note: This work was supported by the Irish Research Council; awarding P.K. an Enterprise Partnership Scholarship.

PY - 2021/12/31

Y1 - 2021/12/31

N2 - Alkoxyamines of TEMPO usually dissociate thermally at >100 °C; however, room temperature homolysis, activated by visible light, occurs with benzimidazolequinone derivatives. 1,1'-Dimethyl-2,2'-bis{[(2,2,6,6-tetramethylpiperidin-1-yl)oxy]methyl}-6-(trifluoromethyl)-1H,1'H-[5,5'-bibenzimidazole]-4,4',7,7'-tetrone (CFÔéâ-Bis-TEMPO-Vis) is prepared in a 59% yield through NBS/HÔééSOÔéä oxidative demethylations of the dimethoxybenzimidazole-benzimidazolequinone precursor with aqueous work up. The alternative basic work up in air gave the epoxide derivative of CFÔéâ-Bis-TEMPO-Vis. Unlike the latter CFÔéâ-epoxide, both alkoxyamine residues are labile under green light (470-600 nm), and the rate of TEMPO release is three times slower than Bis-TEMPO-Vis.

AB - Alkoxyamines of TEMPO usually dissociate thermally at >100 °C; however, room temperature homolysis, activated by visible light, occurs with benzimidazolequinone derivatives. 1,1'-Dimethyl-2,2'-bis{[(2,2,6,6-tetramethylpiperidin-1-yl)oxy]methyl}-6-(trifluoromethyl)-1H,1'H-[5,5'-bibenzimidazole]-4,4',7,7'-tetrone (CFÔéâ-Bis-TEMPO-Vis) is prepared in a 59% yield through NBS/HÔééSOÔéä oxidative demethylations of the dimethoxybenzimidazole-benzimidazolequinone precursor with aqueous work up. The alternative basic work up in air gave the epoxide derivative of CFÔéâ-Bis-TEMPO-Vis. Unlike the latter CFÔéâ-epoxide, both alkoxyamine residues are labile under green light (470-600 nm), and the rate of TEMPO release is three times slower than Bis-TEMPO-Vis.

KW - Chemistry

KW - epoxide

KW - homolysis

KW - kinetics

KW - nitroxide

KW - quinones

KW - radicals

U2 - 10.3390/m1300

DO - 10.3390/m1300

M3 - Article

SN - 1422-8599

VL - 2021

JO - MolBank

JF - MolBank

IS - 4

M1 - M1300

ER -

CFÔéâ-Bis-TEMPO-Vis: new visible light active bis-benzimidazolequinone alkoxyamine

Abstract

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Keywords

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