Chemistry Reference
In-Depth Information
O
OH
COOCH
3
COOCH
3
[NH
2
Me
2
][{RuCl(
S
-DTBM-SEGPHOS
)
}
2
(
μ
-Cl)
3
]
H
2
NHCOC
6
H
5
NHCOC
6
H
5
98.6% de
99.4% ee
OTBS
OAc
NH
O
Scheme 7.8.
Synthesis of a key intermediate of carbapenem antibiotics via asymmetric
hydrogenation.
O
O
OH
O
Ru[(
R
)-MeO-BIPHEP]Br
2
(0.5mol %)
N
COOMe
N
COOMe
CH
2
Cl
2
,50
o
C, 115 atm H
2
NHAc
NHAc
O
O
de: >98%
ee: 100%
OH
H
+
H
2
N
COOH
.2HCl
NH
2
Scheme 7.9.
Synthesis of (2
S
,3
R
) - 3 - hydroxylysine via asymmetric hydrogenation.
phthalimide
- keto esters with Ru - C3 - TunePhos as catalyst (Eq. 7.36 ) [23d] . Gen ê t and
others reported an effi cient partial synthesis of cytotoxic macrolide dolabelide A [262].
Ru-SYNPHOS catalyzed asymmetric hydrogenation of
β
-keto esters was used to gener-
ate three hydroxyl-bearing stereocenters with both high levels of enantio- and
diastereoselectivities.
β
O
O
O
O
OH
OH
Ru[(
S
)-BINAP]I(
p
-cymene)I
+
O
O
O
MeOH/CH
2
Cl
2
(3:1)
trans
ci s
97% ee
(7.32)
cis
:
trans
= 99:1
O
O
OH
O
(COD)Ru(methallyl)
2
+(
R
)-BINAP
CH
2
Cl
2
,80
o
C, 90 atm H
2
OMe
OMe
Cl
Cl
99% ee
98% de
(7.33)
