Chemistry Reference
In-Depth Information
H
2
P
P
P
T
Ru
S
P
129
P
P
H
H
Ru
THF, 67 °C
H
P
P
P
Ru
BT
S
H
2
130
Rh-complex, THF,
S
H
2
30 atm, 120 °C
SH
H
2
S
Scheme 141
Reductive desulfurization of T and BT by [(triphos)RhH] [
157
]
1. (triphos)Ir(H)
2
(THF)]BPh
4
S
2.
t-
BuOK
3. H
2
(30 bar), 160 °C
SH
H
2
S
H
2
(30 bar)
160 °C
displacement
of THF by BT
P
P
P
H
H
P
Ir
P
P
H
H
t-
BuOK
Ir
S
S
Scheme 142
Reductive desulfurization of T and BT by Ir-complex [
158
]
followed by hydrogenation of the cleaved benzo[
b
]thiophene molecule. However,
there are no reports that detail the catalytic opening and hydrogenation of BT
assisted by transition metal complexes (Scheme
140
).
The rhodium hydride, [(triphos)RhH], will react with thiophene and benzo[
b
]
thiophene to yield complexes
129
and
130
, respectively, which yield other
Rh-containing complexes when they were subjected to electrophilic reagents
[
7
]. The catalytic transformation of BT into 2-ethylthiophenol can be achieved
with this soluble rhodium complex (Scheme
141
)[
157
].
DHBT can be readily converted into 2-ethylthiophenol on being reacted with an
iridium complex [
158
]. The mechanism was assessed by in situ multinuclear NMR
spectroscopy, allowing detection of a key intermediate of iridium
1
-DHBT com-
η
plex, which had been reported rarely before (Scheme
142
).
