Abstract
This study aims to develop a facile and efficient synthetic method utilizing iodine
as a catalyst for the deoxygenative coupling of indolin-3-one derivatives with thiols.
Reaction of indolin-3-ones with a range of alkane- and arenethiols with 3 mol% iodine
in 2,2,2-trifluoroethanol at room temperature or 60 °C gave 3-alkylthio- or 3-arylthio-substituted
indoles in 52–98% yields while reaction with arenethiols using 10 mol% iodine, 1.2
equiv sodium hydroxide in acetonitrile gave 2-(arylthio)indoline-3-ones in moderate
yields. Hence, regioselective C–S bond formation, which is produced at the C2 or C3
position of indolin-3-one, was achieved, depending on the presence or absence of a
base and, advantageously, without the need for a transition metal catalyst and additional
synthetic steps.
Key words
iodine - deoxygenative coupling - regioselective C–S bond formation - indolin-3-one
- 3-sulfenyl indole