Chemistry Reference
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Ph
Ph
NH
HN
O
+
Cu(OTf)
2
30
(each 10 mol %)
R
2
N
R
1
NH
+
CH
2
Cl
2
, 0°C
H
2
Et
Ph
O
R
2
R
2
H
+
R
1
O
HN
N
HN
Ph
CO
2
Et
Ph
CO
2
Et
R
1
= Me, R
2
= COC
11
H
23
85% ee (83%)
R
1
= OBn, R
2
= COC
11
H
23
93% ee (94%)
R
1
= OBn, R
2
= COCH
3
94% ee (72%)
Scheme 8D.35.
O
O
O
O
LiAlH(O
t
Bu)
3
/LiI
C
C
BnO
N
H
HN
C
11
H
23
BnO
N
HN
C
11
H
23
Et
2
O, -45
°
C
Ph
CO
2
Et
Ph
CO
2
Et
87%
anti/syn
86/14
H
2
Pd/C
O
N
C
11
H
23
NH
O
Ph
71%
Scheme 8D.36.
8D.5. INTRAMOLECULAR CARBONYL - ENE REACTION
Mikami et al. reported the fi rst examples of “ catalytic ” asymmetric intermolecular
carbonyl-ene reaction by using BINOL-Ti catalyst
1
[70] . The chiral BINOL - Ti catalyst
1
in the presence of AgClO
4
effi ciently functions for both chiral recognition of the enan-
tioface of the aldehyde and discrimination between the diastereotopic protons of the
ene portion (Scheme 8D.40 ).
A chiral box - Cu(II) complex - catalyzed asymmetric intramolecular carbonyl - ene
reactions of unsaturated keto ester is reported (Scheme 8D.41) [71]. In spite of the high
catalyst loading (20 mol %), the use of complex
18b
provides the six-membered cycload-
ducts, and the diastereomeric ratio is more than 50:1.
