DNA Damage Due to Diradical‐Generating Cyclizations

Kerwin, Sean M.

doi:10.1002/9780470526279.ch13

Cited by 6 publications

(5 citation statements)

References 111 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…α,3-Didehydrotoluenes ( A ) have been the subject of intense attention in recent years, in particular due to their potential application in medicine as antitumor agents, as well as to the involved mechanistic issues. These diradicals have been generated by a cycloaromatization process (the Myers–Saito reaction) starting from an enyne–allene ( B ; Scheme , path a) .…”

Section: Introductionmentioning

confidence: 99%

Methoxy-Substituted α,n-Didehydrotoluenes. Photochemical Generation and Polar vs Diradical Reactivity

et al. 2014

View full text Add to dashboard Cite

The photoreactivity of differently substituted (chloromethoxybenzyl)trimethylsilanes in alcohols and alcohol/water mixtures has been investigated by means of a combined computational and experimental approach. Subsequent elimination of the chloride anion and the trimethylsilyl cation gives the corresponding methoxy-substituted α,n-didehydrotoluenes (α,n-MeO-DHTs). The rate of desilylation is evaluated through the competition with arylation via phenyl cation (ca. 10(8) s(-1)). α,2-MeO- and α,4-MeO-DHTs show a purely radical behavior (H abstraction from the solvent, methanol), while α,3-MeO-DHT shows mainly a ionic chemistry, as when the parent α,3-DHT is thermally generated. This is likely due to triplet-singlet surfaces crossing occurring during desilylation.

show abstract

Section: Introductionmentioning

confidence: 99%

Methoxy-Substituted α,n-Didehydrotoluenes. Photochemical Generation and Polar vs Diradical Reactivity

et al. 2014

View full text Add to dashboard Cite

show abstract

“… 25 This rearrangement is also involved in the DNA and RNA strand scission from 2’- and 4’-radicals via the cleavage of the β-phosphate. 26 …”

Section: Introductionmentioning

confidence: 99%

“…In carbohydrate chemistry, this rearrangement has been exploited for a convenient synthesis of 2-deoxypyranoses from 1-pyranosyl radicals and in the stereoselective preparation of purine and pyrimidine α-nucleosides . This rearrangement is also involved in the DNA and RNA strand scission from 2’- and 4’-radicals via the cleavage of the β-phosphate …”

Section: Introductionmentioning

confidence: 99%

1,5-Hydrogen Atom Transfer/Surzur–Tanner Rearrangement: A Radical Cascade Approach for the Synthesis of 1,6-Dioxaspiro[4.5]decane and 6,8-Dioxabicyclo[3.2.1]octane Scaffolds in Carbohydrate Systems

et al. 2021

View full text Add to dashboard Cite

The 1,5-HAT–1,2-(ester)alkyl radical migration (Surzur–Tanner rearrangement) radical/polar sequence triggered by alkoxyl radicals has been studied on a series of C -glycosyl substrates with 3- C -(α,β- d , l -glycopyranosyl)1-propanol and C -(α- d , l -glycopyranosyl)methanol structures prepared from chiral pool d - and l -sugar. The use of acetoxy and diphenoxyphosphatoxy as leaving groups provides an efficient construction of 10-deoxy-1,6-dioxaspiro[4.5]decane and 4-deoxy-6,8-dioxabicyclo[3.2.1]octane frameworks. The alkoxyl radicals were generated by the reaction of the corresponding N -alkoxyphthalimides with group 14 hydrides [ n -Bu 3 SnH(D) and (TMS) 3 SiH], and in comparative terms, the reaction was also initiated by visible light photocatalysis using the Hantzsch ester/ fac -Ir(ppy) 3 procedure. Special attention was devoted to the influence of the relative stereochemistry of the centers involved in the radical sequence on the reaction outcome. The addition of BF 3 •Et 2 O as a catalyst to the radical sequence resulted in a significant increase in the yields of the desired bicyclic ketals.

show abstract

“…Although the vast majority of the work reported in this area has been focused on anomeric radicals of hexopyranose systems, the conformation, lifetime, and reactivity of the C4 radical in pentofuranoses have also been investigated in some detail . The importance of these radicals in the DNA damage through the metabolism of oxygen and in the mode of action of certain DNA cleavage agents (e.g., iron bleomycin, (1,10-phen) 2 Cu complex, and enediyne natural products) has motivated these studies …”

Section: Introductionmentioning

confidence: 99%

Intramolecular 1,8-Hydrogen Atom Transfer Reactions in Disaccharide Systems Containing Furanose Units

et al. 2012

View full text Add to dashboard Cite

A previously developed 1,8-hydrogen atom transfer (HAT) reaction promoted by 6-O-yl alkoxyl radicals between the two pyranose units in Hexp-(1→4)-Hexp disaccharides has been extended to other systems containing at least a furanose ring in their structures. In Penf-(1→3)-Penf (A) and Hexp-(1→3)-Penf (B) disaccharides, the 1,8-HAT reaction and concomitant cyclization to a 1,3,5-trioxocane ring are in competition with radical β-scission of the C4-C5 bond and formation of dehomologated products. The influence of the stereoelectronic β-oxygen effect on the β-scission and consequently on the 1,8-HAT reaction has been studied using the four possible isomeric d-furanoses. d-xylo- and d-lyxo-derivatives afforded preferentially 1,8-HAT products, whereas d-arabino- and d-ribo-derivatives gave exclusively direct β-scission of the alkoxyl radical. When the 6-O-yl radical is on a pyranose ring, as occurs in Penf-(1→4)-Hexp (C), it has been shown to provide the cyclized products exclusively.

show abstract

DNA Damage Due to Diradical‐Generating Cyclizations

Cited by 6 publications

References 111 publications

Methoxy-Substituted α,n-Didehydrotoluenes. Photochemical Generation and Polar vs Diradical Reactivity

Methoxy-Substituted α,n-Didehydrotoluenes. Photochemical Generation and Polar vs Diradical Reactivity

1,5-Hydrogen Atom Transfer/Surzur–Tanner Rearrangement: A Radical Cascade Approach for the Synthesis of 1,6-Dioxaspiro[4.5]decane and 6,8-Dioxabicyclo[3.2.1]octane Scaffolds in Carbohydrate Systems

Intramolecular 1,8-Hydrogen Atom Transfer Reactions in Disaccharide Systems Containing Furanose Units

Contact Info

Product

Resources

About