Chemistry Reference
In-Depth Information
Cu(O-
t
-Bu)
Ligand
62
THF
B
(pin)
Ph
+B
2
(pin)
2
Ph
OCO
2
Me
(
Z
)-
60
61
(85%, 95% ee)
Me
t
-Bu
O
N
P
O
B
B
O
O
B
2
(pin)
2
N
P
Ligand
62
t
-Bu
Me
P
P
P
(pin)B
(pin)B
Cu
P
Cu
C
C
Ph
Ph
C
C
OCO
2
Me
OCO
2
Me
61
H
H
H
H
Scheme 5.19.
OH
[Pd(C
3
H
5
)Cl]
2
O
O
N
O
O
Ligand
43
+
HN
+
N
O
OH
CH
2
Cl
2
63
O
99%
O
64
:
65
= 75:1
64
(98% ee)
65
O
OH
O
H
N
N
H
O
O
O
O
HO
OH
Pd+
(+)-Broussonetine G
L
L
Scheme 5.20.
The ability to perform a DYKAT using the palladium-catalyzed reaction of racemic
vinyloxirane
63
with phthalimide was explored by Trost and others (Scheme 5.20) [25].
The 1,2 - adduct
64
was obtained in nearly quantitative yield and 98% ee by using ligand
43
[25a,b]. In this reaction, the hydrogen bond of the nucleophile to the oxygen leaving
group would deliver the nucleophile to the adjacent carbon to give 1,2-adduct
64
pre-
dominantly. This DYKAT process potentially provides a concise access to the brous-
sonetine family such as (+) - broussonetine G [25c] .
