Photochemical co-oxidation of sulfides and phosphines with tris(p-bromophenyl)amine. A mechanistic study.

BONESI, SERGIO MAURICIO; PROTTI, STEFANO; ALBINI, ANGELO

JOURNAL OF ORGANIC CHEMISTRY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2018 vol. 83 p. 8104 - 8113

0022-3263

The photochemistry of tris(p-bromophenyl)amine was investigated in nitrogen- and oxygen-flushed solution under laser flash photolysis conditions. Intermediates detected were the corresponding amine radical cation (?Magic Blue?) and the N-phenyl-4a,4b-dihydrocarbazole radical cation that, under an oxygen atmosphere is converted to the corresponding hydroperoxyl radical. The role of the last species was supported by the smooth co-oxidation of sulfides to sulfoxides. On the other hand, co-oxidation of nucleophilic triarylphosphines to triarylphosphine oxides arose from an electron transfer process between the photogenerated "Magic Blue" and phosphine that prevented the amine cyclization. In this case, intermediate Ar3POO?+ was found to play a key-role in phosphine oxide formation.