Chemistry Reference
In-Depth Information
NO
N
N
Ru
OO
X
1a, 10
d
n
4
r
4
n
g
|
1
R = alkyl or hydroxyalkyl
RCH
2
OH
h
ν
−
NO
H
H
R
R
n
n
H
H
R
H
O
O
R
OH
OH
OH
n
H
OH
O
O
N
N
OH
OH
N
N
N
N
Ru
IV
Ru
Ru
OO
X
OO
X
OO
X
O
2
+ HOOH
(for monool oxidation)
+ HOOH
(for diol oxidation)
R = hydroxyalkyl
R = alkyl
O
2
h
ν
SET
RDS
(X = OH)
RDS
(X = Cl)
RDS
(X = OH)
HAT
HAT
H
H
H
R
R
n
H
O
P
1
OP
1
O
H
OP
1
N
N
N
N
N
N
IV
IV
III
Ru
Ru
Ru
OO
OO
OO
X
X
X
Y
Y
Y
OO
-
Y =
(P
1
= H or none)
or
OOH
.
Scheme 9.14 Proposed mechanisms
for Ru(salen)-catalyzed aerobic
alcohol
oxidation.
1a
(2- 5 mol% )
air
h
R
(
R
)
N
NO
N
R
OH
OH
Ru
ν
2
O
Ph
O
Cl
OH
Ph
25 ºC
(
R
)
R
R = H, 72 %, 65% ee
R = Br, 77 %, 69% ee
R = C
≡
CPh, 93%, 68% ee
1a
Scheme 9.15 Ru(salen)-catalyzed
oxidative
coupling
of
2-naphthols
under
photoirradiation.
2,2
0
-dihydroxystilbene derivatives with moderate to good enantioselectivity
to give chiral 2,3-dihydrobenzofurans (Scheme 9.16).
28b
Recently, highly
enantioselective catalysis of aerobic oxidative coupling of 2-naphthols by
vanadium complexes (12 and 13) have been reported (Scheme 9.17).
29-31
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