91239-44-0Relevant articles and documents
Photostimulated Reaction of Diphenylarsenide and Diphenylstibide Ions with Haloaromatic Compounds by the SRN1 Mechanism. Electron Transfer vs. Bond Breaking of the Radical Anion Intermediate
Alonso, Ruben A.,Rossi, Roberto A.
, p. 77 - 80 (1982)
Photostimulated reactions of haloaromatic compounds with potassium diphenylarsenide and potassium diphenylstibide were studied in liquid ammonia. 1-Bromonaphthalene and 9-bromophenanthrene reacted with diphenylarsenide ion to give four products: triphenylarsine, diphenylarylarsine, phenyldiarylarsine, and triarylarsine (aryl = 1-naphthyl and 9-phenanthryl); with 2-chloroquinoline as substrate only the straightforward substitution product 2-qiunolyldiphenylarsine was formed. p-Bromoanisole and 4-chlorobenzophenone reacted with potassium diphenylstibide to give four stibines: triphenylstibine, diphenylarylstibine, phenyldiarylstibine, and triarylstibine (aryl = p-anisyl and 4-benzoylphenyl).These reactions are believed to occur by the SRN1 mechanism with an extra feature of reversible coupling of aryl radicals with arsenide and stibide ions, which causes the scrambling of aryl rings.It is suggested that the low-lying ?* MO of the quinolyl moiety prevents C-As bond breaking of the radical anion intermediate.
Relative Reactivities of Amide, Diphenylphosphide, and Diphenylarsenide Ions toward Aryl Radicals
Alonso, Ruben A.,Bardon, Alicia,Rossi, Roberto A.
, p. 3584 - 3587 (2007/10/02)
Competition experiments have been carried out in liquid ammonia at reflux temperature to determine the relative rate constants for the coupling reactions of amide (NH2-), diphenylphosphide (Ph2P-), and diphenylarsenide (Ph2As-) toward aryl radicals.It is proposed that these nucleophiles react under photostimulation with halo aromatic substrates through an SRN1 mechanism of aromatic substitution.Relative rate constants of NH2- vs.Ph2P- ions toward 2,4,6-trimethylphenyl radicals and Ph2P- vs.Ph2As- ios toward 2-quinolyl radicals have been determined.The results here reported indicate that NH2- (1.00) - (6.4) = Ph2As- (6.4).The fact that there is not a difference in the rate constants of Ph2P- vs.Ph2As- suggests that both nucleophiles react at diffusion-controlled rate.In competition experiments of Ph2P- vs.Ph2As- ions toward phenyl radicals, it was found that Ph2P- (1.00) > Ph2As- (0.44).The decrease of the Ph2As- ion reactivity is attributed to the reversible coupling of this nucleophile with phenyl radicals.
