Chemistry Reference
In-Depth Information
Table 9.11
Substrate
Product
Yield (%)
•
TsN
O
TsN
R
2
•
R
1
R
1
R
2
R
1
R
2
Me
H
H
H
Ph
Me
67
74
53
•
O
O
O
45
•
A carbonylated bicyclic enone was isolated in reasonable to high yields depending upon
the reaction conditions. The bisallenes serve both as an excellent alkene- and alkyne-type
moiety in the PK-type [2
1] cycloaddition with carbon monoxide.
They investigated the carbonylative cycloaddition of other bisallenes under optimized
reaction conditions (0.3 mmol allene, 5 mol%
Co
2
Rh
2
catalyst, 2 atm CO, 3 mL toluene,
100
◦
C, and 4 h) (Table 9.11). The corresponding intramolecular [2
+
2
+
1] cocyclization
product was isolated in reasonable to high yield. The high degree of regiocontrol is
noteworthy.
+
2
+
9.5
Sequential Action of Two Different Catalysts in One-Pot Reactions
Although significant breakthroughs regarding the development of tandem reactions have
been achieved recently, those in the field of PKR are relatively rare. The first demonstration
was reported by Jeong's group in 2000.
53
They showed the multiple C-C bond forming
transformations using two different Pd and Rh complexes as catalysts (Scheme 9.22).
R
Cat 1: Pd
Cat 2: Rh
R
OAc
Z
O
+
HZ
R
Cat 1
cat 2
Z
Scheme 9.22
