coupling oxidation, fluorination, and iodination. More recently, various sterically
hindered pyridyl-imidazoline and phenanthroline derivatives were successfully
employed as ligands in the silylation of unactivated arenes and heterorenes
[160, 161].
The hydrosiloxane HSiMe(OSiMe 3 ) 2 was also employed in the directed
dehydrogenative silylation of functionalized arenes and alkanes, using [Ir(μ-Cl)
N
N
Me
Ir
N
O
O
+ Et 3 SiH - Et 3 SiOAc
Et 3 SiH
Et 3 SiH
N
SiEt 3
2-phenylpyridine
51
N
N
Me
Ir
N
H
N
N
Me
Ir
N
Si
H
NBE
NBA
N
N
Me
Ir
N
Si
N
N
Me
Ir
N
Si
H
Si
N
N
Me
Ir
N
Si
H
Si
N
N
Me
Ir
N
Si
H
Si
TS
TS
2-phenylpyridine
Scheme 32 Catalytic cycle proposed for the dehydrogenative silylation of 2-phenylpyridine with
51
+
[Ir(µ-OMe)(COD)] 2
dmphen
120 ºC
Si
Up to 87% yield
H
O
O
O
N
R 1
R 2
Si
O
O
O
N
R 1
R 2
- H 2
Scheme 33 Acceptorless silylation of arenes with 1-hydrosilatrane
258
M. Iglesias and L. A. Oro
hindered pyridyl-imidazoline and phenanthroline derivatives were successfully
employed as ligands in the silylation of unactivated arenes and heterorenes
[160, 161].
The hydrosiloxane HSiMe(OSiMe 3 ) 2 was also employed in the directed
dehydrogenative silylation of functionalized arenes and alkanes, using [Ir(μ-Cl)
N
N
Me
Ir
N
O
O
+ Et 3 SiH - Et 3 SiOAc
Et 3 SiH
Et 3 SiH
N
SiEt 3
2-phenylpyridine
51
N
N
Me
Ir
N
H
N
N
Me
Ir
N
Si
H
NBE
NBA
N
N
Me
Ir
N
Si
N
N
Me
Ir
N
Si
H
Si
N
N
Me
Ir
N
Si
H
Si
N
N
Me
Ir
N
Si
H
Si
TS
TS
2-phenylpyridine
Scheme 32 Catalytic cycle proposed for the dehydrogenative silylation of 2-phenylpyridine with
51
+
[Ir(µ-OMe)(COD)] 2
dmphen
120 ºC
Si
Up to 87% yield
H
O
O
O
N
R 1
R 2
Si
O
O
O
N
R 1
R 2
- H 2
Scheme 33 Acceptorless silylation of arenes with 1-hydrosilatrane
258
M. Iglesias and L. A. Oro