New insights on the reaction of trialkyl phosphites with 2-phenyl-3-phenylimino-3H-indole N-oxide: an indolic nitrone. Crystal structures of 1-diethylphosphoryl-2-phenyl-3-phenylamino-1H-indole and 2-phenyl-4-phenylimino-4H-3,1-benzoxazine
S. Canestrari et al., New insights on the reaction of trialkyl phosphites with 2-phenyl-3-phenylimino-3H-indole N-oxide: an indolic nitrone. Crystal structures of 1-diethylphosphoryl-2-phenyl-3-phenylamino-1H-indole and 2-phenyl-4-phenylimino-4H-3,1-benzoxazine, J CHEM S P2, 4, 2000, pp. 833-838
Citations number
47
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
2-Phenyl-3-phenylimino-3H-indole N-oxide (an indolic nitrone) reacts with t
riethyl and triisopropyl phosphite in refluxing xylene and tert-butylbenzen
e to give 2-phenyl-3-phenylimino-3H-indole (indolenine) in very good yield.
The same reaction carried out in refluxing phosphite gave rise to a series
of compounds which in part derive from the thermal rearrangement of the st
arting nitrone and in part from the interaction of the indolenine with phos
phites. The formation of the products arising from the reduction of the ind
olenine is explained by an electron transfer process between this intermedi
ate and the phosphite; whereas the formation of the phosphorylated products
is interpreted through the evolution of the intermediate zwitterion genera
ted by the nucleophilic attack of the phosphite on carbon-2 of the indoleni
ne. The formation of this intermediate is also discussed in terms of an ele
ctron transfer process. Crystal structures of 1-diethylphosphoryl-2-phenyl-
3-phenylamino-1H-indole and 2-phenyl-4-phenylimino-4H-3,1-benzoxazine are a
lso described.