Chemistry Reference
In-Depth Information
O
H
(OC)
3
Co
Co(CO)
3
Chiral amine
N
-oxide (4)
R
R
H
DME, -60 °C
H
1c
R= CMe
2
OH
1d
R= CEt
2
OH
2d-g
34-78% ee
1e
R =
1f
R =
1g
R =
OH
OH
OH
O
N
O
MeO
O
H
H
H
N
N
N
MeO
H
N
N
N
N
H
H
H
H
O
O
O
O
Brucine
N
-oxide (
4a
)
(-)-sparteine
N
16-oxide (
4b
)
(+)-sparteine
N
1-oxide (
4c
)
(-)-17-oxosparteine
N
-oxide (
4d
)
H
H
N
HO
O
N
O
N
O
MeO
N
O
N
N
H
O
N
4e
4f
4g
4h
Scheme 6.8
Asymmetric PKRs promoted by chiral
N
-oxides. The
N
-oxides depicted are those
reported in the literature.
CO
OC
OC
CO
Co
Co
CO
Ent-2c
OH
CO
OC
CO
OC
OC
CO
OC
OC
CO
CO
OC
CO
- R*
3
N
-CO
2
Co
Co
Co
Co
Co
Co
OC
CO
OC
OC
O
NR*
3
O H
OH
OH
1c
O
HO
2c
Scheme 6.9
PKR promoted by a chiral
N
-oxide and anchimerically assisted by propargylic
substrates.
