Chemistry Reference
In-Depth Information
(
R
)
10
OH
(2-4 mol%)
air , h
ν
R
R
N
NO
N
OH
OH
(CH
2
)
n
(CH
2
)
n
O
Ru
d
n
4
r
4
n
g
|
1
CHCl
3
rt
O
Ar
O
X
Ar
(
R
)
O
PDC
MS 4 Å
C2''
(CH
2
)
n
O
CH
2
Cl
2
10a
:R=Me,X=Cl,Ar=Ph
10b
:R=Me,X=OH,Ar=
p
-Ph-C
6
H
4
10c
:R=H, X=Cl,Ar=
p
-TBDPS-C
6
H
4
OH
OH
OH
OH
O
O
O
O
10a
(2 mol%)
10b
(ent)
(4 mol%)
49% , 59% ee
57%, 6 5% ee
57%, 67% ee
64% , 63% ee
64% , 74% ee
78%, 6 6% ee
80%, 80% ee
80% , 63% ee
Ph
Ph
OH
OH
OH
OH
OH
Ph
c
-Hex
O
O
.
O
O
O
Ph
c
-Hex
Ph
Ph
10a
(2 mol%)
10b
(ent)
(2-4 mol%)
66% , 66% ee
82 %, 81% e e
40% , 9% ee
90% , 16% ee
73%, 21% ee
68% , 75% ee
55 %, 79% e e
68% , 1% ee
52% , 36% ee
-
10c
(e nt)
(2-4 mol%)
-
67 %, 68% e e
82% , 62% ee
99% , 93% ee
96%, 90% ee
Scheme 9.13 Ru(salen)-catalyzed aerobic oxidative desymmetrization of meso-diols
under air.
numerous studies on transition metal-catalyzed asymmetric aerobic oxida-
tive coupling of 2-naphthols have been performed
27
but most of them use
pure dioxygen as oxidant, owing to the low partial pressure of oxygen in air.
Ruthenium-salen complex 1, which is an ecient catalyst for OKR of
secondary alcohols using air as oxidant, was found to catalyze the AOC of
2-naphthols in air under irradiation, albeit with moderate selectivity
(Scheme 9.15).
28a
A similar Ru(salen) complex bearing diphenylethylene-
diamine moiety 11 also catalyzed the oxidative intramolecular coupling of
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