Reactivity of Aryl and Vinyl Radicals: Abstraction of Hydrogen Atom or Reaction with a Nucleophile

Branchi, Barbara; Galli, Carlo; Gentili, Patrizia

doi:10.1002/1099-0690(200208)2002:16<2844::aid-ejoc2844>3.0.co;2-9

Cited by 40 publications

(39 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This concentration dependence would indicate that the radical + anion coupling reaction (symbolized in equation 3) between naphthyl radicals and the pinacolone enolate and the hydrogen abstraction reaction from DMSO (equation 8) do not differ by more than 2-3 orders of magnitude. This latter conclusion is entirely consistent with the independently determined values for the rate constants (k H = 6.4 x 10 6 M -1 s -1 ) 11 involving naphthyl radicals (without perisubstituents) in hydrogen abstraction reactions with DMSO and the rate constant for coupling of the α-naphthyl radical with the enolate anion of pinacolone (2.9 x 10 9 M -1 s -1 ).…”

Section: Mechanistic Implicationssupporting

confidence: 88%

The SRN1 reactions of 1,8-diiodonaphthalene

Norris¹,

McMahon²

2003

Arkivoc

View full text Add to dashboard Cite

The reactions of 1,8-diiodonaphthalene with the enolate ions from pinacolone and acetone, and with p-toluenethiolate, mesitylenethiolate, and diethylphosphite ions in DMSO or liquid ammonia have been studied. In these S RN 1 (or related radical) processes, disubstitution, without isolation of the monosubstituted monoiodo compound takes place with the enolate ions to give ultimately (after a subsequent aldol condensation) substituted dihydrophenalenes. With ptoluenethiolate ion a novel thiaxanthene system results. With mesitylenthiolate ion and diethylphosphite ions, monosubstitution with monoreduction occurs. Deuterium labeling experiments show that the major source of hydrogen (deuterium) necessary for the reduction process arises from DMSO by a radical abstraction reaction.

show abstract

Section: Mechanistic Implicationssupporting

confidence: 88%

The SRN1 reactions of 1,8-diiodonaphthalene

Norris¹,

McMahon²

2003

Arkivoc

View full text Add to dashboard Cite

show abstract

“…The solvent was removed under reduced pressure. (14); 88 (9). 1-Naphthyl-2-methoxynaphthalene (10c).…”

Section: Photostimulated Reaction Of Me 3 Sn Ions With 1-chloro-2-metmentioning

confidence: 99%

Steric effects in the synthesis of ortho-substituted 1,1'-binaphthalene derivatives by the SRN1 and the Stille reaction

Baumgartner¹,

Tempesti²,

Pierini³

2003

Arkivoc

View full text Add to dashboard Cite

The scope of the S RN 1 mechanism and the Stille reaction to synthesize 1,1´-binaphthalene derivatives was investigated. The best yield of 2'-methoxy-1,1'-binaphthalenyl-2-ol (52%) was obtained in liquid ammonia or DMSO by the S RN 1 irradiated reaction of 1-iodo-2-methoxynaphthalene with the anion of 2-naphthol. A lower yield (40%) of BINOL is obtained in water with 1-iodo-2-hydroxynaphthalene as substrate when the reaction is sonicated before irradiation. The Stille reaction between (2-methoxy-1-naphthyl)-trimethylstannane and 1-iodo-2-methoxynaphthalene afforded low yields (15-11%) of the 1,1´-binaphthalene derivative. Based on AM1 and B3LYP calculations the yields of the 1,1´-binaphthalene derivatives obtained through the electron transfer S RN 1 reaction can be attributed to kinetic factors of the radicalnucleophile coupling step.

show abstract

“…The same substrate, however, affords the substitution product derived from the elimination/addition route when a carbanion is employed [145]. A mechanistic study was undertaken on the coupling of vinyl radicals with nucleophiles ((EtO) 2 PO -, -CH 2 COBu-t, and PhS -ions) and the competing H-atom abstraction reactions from various solvents (MeCN, DMSO) [146]. For radical 73, the rate constant for H abstraction in DMSO was 1.1 x 10 5 M -1 s -1 , and that for coupling with PhS -ions was calculated to be 1.9 x 10 7 M -1 s -1 (Scheme 26, k H and k subst ) respectively.…”

Section: Vinyl Halidesmentioning

confidence: 99%