Reactivity of sulfur centered nucleophiles in photoinduced reactions with 1-bromonaphthalene

JUAN E. ARGÜELLO; LUCIANA C. SCHMIDT; ALICIA B. PEÑÉÑORY

Arkivoc

ARKAT USA, Inc.

Año: 2003 p. 411 - 411

1424-6376

he reactivity of S2- (1), -SCN (2) and -SCNH(NH2) (3) in photoinduced substitution reactions with 1-bromonaphthalene (5) in DMSO was studied. The photostimulated reaction of ion 1 with 5 renders after quenching with MeI 1-(methylthio)naphthalene (16%), bis (1-naphthyl) sulfide (17.5%) and naphthalene (42%). The lack of reaction in the dark and the inhibition of the photoinduced one by the presence of di-tert-butylnitroxide (DTBN) and p-dinitrobenzene (p- DNB) are evidence of a radical chain mechanism for these substitution reactions. On the other hand, ion 2 was unreactive towards 5, both as an electron donor under photostimulation and as a nucleophile. Finally the thiourea anion (3) affords after a photoinduced reaction with 5 and quenching with MeI, 1-methylthionaphthalene (50%), bis (1-naphthyl) sulfide (22%) and naphthalene (9%). This reaction does not occur in the dark and is inhibited in the presence of DTBN. By using hydrogen abstraction from DMSO as competitive reaction, the a