Chemistry Reference
In-Depth Information
Chiral phosphanes:
t
-Bu
O
i
-Pr
O
i
-Pr
N
H
N
NH
n
Bu
N
NH
n
Bu
N
NH
n
Bu
N
O
O
PPh
2
O
PPh
2
Ph
24
PPh
2
27
26
OtBu
Substrates:
O
2.4-10 mol %
26, 27, 24
1-4 mol % (CuOTf)
2
•C
6
H
6
[(alkyl)
2
Zn], PhCHO, toluene,
-30
O
OH
O
O
Oxidation
O
O
Ph
O
Ph
()
n
()
n
()
n
°
C
Alkyl
Alkyl
Alkyl = Et, Me,
i-
Pr, Me
2
CH(CH
2
)
3
up to >98%
ee
O
O
5 mol%
26
2 mol % (CuOTf)
2
•C
6
H
6
[(alkyl)
2
Zn], THF, -30
°
C
O
O
Alkyl
Alkyl = Et, Me
Up to >98% ee
O
10 mol %
26
or
24
4 mol % (CuOTf)
2
•C
6
H
6
[(alkyl)
2
Zn], PhCHO, toluene,
-30
O
OH
H
()
n
()
n
Ph
O
O
°
C, 24 h
Alkyl
Alkyl = Et,
i-
Pr
Up to >98% ee
Scheme 8A.18.
NO
2
NO
2
t
-Bu
O
N
Et
1-10 mol %
29
N
NHBu
0.5-5 mol % (CuOTf)
2
•C
6
H
6
, 3 equiv R
2
Zn
Toluene, 0
O
(
n
()
n
PPh
2
C, aq. NH
4
Cl
°
Up to 96%
ee
OBn
n
= 0,1,2,7;
R = Me, (CH
2
)
3
CHMe
2
, (CH
2
)
4
OAC
29
Scheme 8A.19.
1% Cu(OTf)
2
2%
30
Toluene, -55°C
R'
Ph
RO
NO
2
+R'
2
Zn
RO
NO
2
*
O
O
P
N
OR
OR
Ph
88-98%
ee
Up to 86% yield
R = Me, CH
2
C(CH
3
)
2
CH
2
, CH
2
C(Ph)
2
CH
2
,
C(CH
3
)
2
C(CH
3
)
2
R' = Et, Me, Bu, (CH
2
)
6
CO
2
Me
(S,R,R)-
30
Scheme 8A.20.
