Chemistry Reference
In-Depth Information
Table 8.3
BQ (3) catalysed
-lactam synthesis
b
Ts
O
Ts
3
(10 mol%)
O
Cl
N
N
Proton Sponge™ (
1
)
EtO
2
C
H
R
1
R
1
EtO
2
C
toluene, -78 °C
R
1
yield (%)
cis
/
trans
ee (%)
BzO
Ph
65
99/1
96
N
Bn
60
33/1
96
BnO
65
99/1
96
N
Et
57
99/1
99
CH
¼
CH
2
58
99/1
98
OMe
N
3
47
25/1
98
3
8.4.2 Pericyclic Reaction
Some applications of Proton Sponge (1) for pericyclic reactions have been reported.
Intramolecular Diels-Alder (IMDA) reaction of triene proceeded under thermal conditions
to give bicyclic compound. In this reaction, the yield of the IMDA reaction for the Lewis
acid labile substratewas significantly improved to 57% in the presence of a catalytic amount
of Proton Sponge (1) (0.3 equiv.) [28] (Scheme 8.9). A similar effect was observed in the
IMDA reaction of ester derivative. Whitney et al. conducted the IMDA reaction of acrylate
Table 8.4
BQ (3) catalysed
-amino acid synthesis
b
3
(10 mol%)
PhOC
COPh
O
Cl
Proton Sponge™ (
1
)
MeOH
NH
N
CO
2
Me
reflux
EtO
2
C
EtO
2
C
H
toluene, -78 °C
R
1
R
1
3
R
1
yield (%)
cis
/
trans
ee (%)
H
COPh
N
Ph
62
12/1
95
EtO
2
C
l
PhO
63
14/1
95
p
-MeOC
6
H
4
p
-ClC
6
H
4
62
10/1
94
60
12/1
94
