Chemistry Reference
In-Depth Information
t
BuMe
2
SiO
CO
2
H
H
O
OH
O
L-5
(10 mol %)
+
PhCHO
Ph
H
2
O
syn
/
anti
= 1:19
61% yield, >99% ee (
anti
)
C
10
H
21
N
C
10
H
21
H
O
O
P
h
L-6
(10 mol %)
NO
2
NO
2
+
Ph
TFA, brine
syn
/
anti
= 95:5
93% yield, 89% ee
Scheme 1.19.
OTBDPS
CO
2
H
OCH
3
O
O
N
HPMP
NH
2
L-7
(10 mol %)
H
2
O, rt, 24 h
O
+
H
+
OR
1
OBn
NO
2
NO
2
NH
2
90% yield,
syn
/
anti
= 1:6, 93% ee (
anti
)
Scheme 1.20.
O
O
N
H
Bn
•HClO
4
L-8
(20 mol %)
H
2
O, 0°C
O
+
Et
Et
O
89% yield,
endo
:
exo
= 25:1, 90% ee
Scheme 1.21.
The conjugate addition reaction of terminal alkynes to C=C bond can be catalyzed
by copper in water. The reaction only proceeds with derivatives of Meldrum's acids in
the presence of Cu(I) produced by Cu(OAc)
2
and sodium ascorbate in water, and a large
excess amount of phenylacetylyne. Combined with chiral ligand
L - 10
, enantioselective
versions of this addition reaction can be achieved to 82-97% ee of products with useful
yields [27] (Scheme 1.23 ).
