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1a
(2 mol%)
O
O
2
(5 mol%)
air
OH
OH
O
+
R
1
R
2
R
1
R
2
R
1
R
2
h
ν
, rt
Br
Br
d
n
4
r
4
n
g
|
1
2
OH
OH
OH
OH
R
R = H conv. = 61%
ee = 98%,
conv. = 54%
ee = 82%,
conv. = 58%
ee = 99%,
conv. = 41%
ee = 55%,
k
rel
= 19 (±1)
k
rel
= 14 (±1)
k
rel
= 30 (±2)
k
rel
= 15 (±1)
R = Cl conv. = 57%
ee = 95%,
k
rel
= 23 (±1)
R = Br conv. = 54%
ee = 90%,
k
rel
= 22 (±1)
Scheme 9.4 Kinetic resolution of racemic secondary alcohols with bidentate ligand-
supported ruthenium-salen complex 1a.
[Pd(nbd)Cl
2
] (5 mol%)
( -)-sparteine (12 mol%)
ambient air (1 atm)
OH
OH
O
N
N
+
R
1
R
2
R
1
R
2
R
1
R
2
3Å MS, Cs
2
CO
3
(0.4 equiv)
CHCl
3
, 23 ºC
(-)-sparteine
.
OH
OH
OH
R
R = OMe conv. = 62.3%
ee = 99.8%,
conv. = 55.5%
ee = 98.0%,
k
rel
= 37.3
conv. = 60.2%
ee = 99.6%,
k
rel
= 28.0
k
rel
= 25.4
R = F conv. = 56.7%
ee = 93.0%,
k
rel
= 19.5
OH
OH
conv. = 64.7%
ee = 98.9%,
conv. = 56.8%
ee = 94.9%,
k
rel
= 15.7
k
rel
= 21.7
Scheme 9.5 Pd-sparteine complex-catalyzed oxidative kinetic resolution of second-
ary alcohols under ambient air.
With the notion that the Cp*iridium-amide complex should show a re-
verse transfer dehydrogenation catalysis, Ikariya and co-workers examined
the OKR of secondary alcohols with Cp*iridium-amide complex 4a bearing
an N-menthanesulfonylated diamine ligand and developed the highly
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