Chemistry Reference
In-Depth Information
TABLE 8B.7. Results Obtained for Reactions according to Scheme 8B.16 with P , N - Ligands
Developed in Tarragona and Madison, WI
N
O
t
-Bu
O
O
O
N
H
∗
PPh HN
t
-Bu
O
N
P
L16a
:R*=
CO
2
Me
O
R*HNOC
∗
R*
O
R
L16b
:R*=
t
-Bu
CO
2
Me
t
-Bu
L15a
R=Ph
L15b
R=
t
-Bu
L15c
R=
i
-Pr
Conditions
a
Entry
R or n
X
L
Yield (%)
ee (%)
Reference
1
Ph
OAc
L15a
KOAc, rt, 5 min
100
b
99
96
2
CH
3
O A c
L15b
KOAc, rt, 30 min
100
b
81
96
3
5
O A c
L15a
KOAc, rt, 30 min
100
b
90
96
4
6
O A c
L15c
KOAc, rt, 30 min
100
b
94
96
100
b
5
7
O A c
L15c
KOAc, rt, 30 min
93
96
6
Ph
OAc
L16a
NaOAc, rt
99
97
98
7
CH
3
O A c
L16b
NaOAc, rt
92
92
98
a
Pronucleophile and conditions: CH
2
(CO
2
Me)
2
, [Pd(
π
- C
3
H
5
)Cl]
2
, BSA, CH
2
Cl
2
, NaOAc, or KOAc.
b
Conversion.
TABLE 8B.8. Reactions according to Scheme 8B.16 ( X = OA c , N u H = CH
2
( CO
2
M e )
2
) with a
P , S - Ligand Developed by Evans et al. [44]
Entry
a
R o r n
L
Yield (%)
ee (%)
Reference
O
*
R
2
P
1
Ph
(1
R
,2
R)
-
L2a
97
98 (
S
)
4 4
S
t
-Bu
L2a
R=Ph
L2b
R=1-naphth
2
CH
3
(1
R
,2
R)
-
L2a
87
65 (
S
)
4 4
3
6
(1
S
,2
R)
-
L2b
91
94 (
R
)
4 4
a
Reaction conditions: [Pd(π - C
3
H
5
)Cl]
2
, BSA, KOAc, CH
2
Cl
2
, − 20 ° C.
8B.2.2.2.4. Allylic Alkylation of Selected Cyclic Substrates
In addition to the standard
substrates described above, further interesting cyclic allylic substrates, with a symmetric
substitution pattern, were successfully used in Pd-catalyzed allylic alkylations. Examples
of piperidine derivatives and other heterocycles are described in Table 8B.9. Some of
the products were used in natural product synthesis. For example, the alkylated piperi-
dine derivative was used in a short and effi cient synthesis of
nipecotic acid
[99] .
Hamada et al. [101] reported allylic alkylations of cycloalk-2-enyl carbonates with a
substituent in position 2 (Table 8B.10). A monodentate ligand (
9 - PBN
(
L17
)) was used
