Chemistry Reference
In-Depth Information
X
X
D
R
R
R
R
Y
Y
Fig. 8 Thermal
E
,
Z
-isomerization of 2,2
0
-disubstituted BAEs
a
b
c
d
Fig. 9 Conformational isomerization processes in BAEs: (a) enantiomerization of twisted BAEs;
(b) conformational inversion of
anti
-folded BAEs; (c)
syn
-folded to
anti
-folded; (d) twisted to
anti
-folded conformational isomerizations
Table 2 Selected dynamic NMR results for BAEs
G
c
{
(kcal/
mol)
ʔ
T
c
(
C)
X,Y
Substitution
Process
ʔʽ
(Hz)
Solvent
References
—2-
i
-Pr-
Enantiom.
10.6
0.1
51.3
55
CDFCl
2
[
54
]
2,2
0
-di-Me-
—
E
,
Z
24.9
2.0
170
DMSO-d
6
[
54
]
O, — 2-
i
-Pr
Enantiom.
6.3
0.2
58
139
CDFCl
2
[
62
]
O, — 2-
i
-Pr
E
,
Z
19.6
0.2
3.6
84
CDCl
3
[
62
]
2,2
0
-di-Me-
O
E
,
Z
17.5
0.3
2.6
44
CDBr
3
[
170
]
2,2
0
-di-
i
-Pr-
O
E
,
Z
17.9
0.3
3.4
47
CDCl
3
[
170
]
2,2
0
-di-
i
-Pr-
O
Inversion
17.7
0.5
0.9
36
CDCl
3
[
170
]
2,2
0
-di-Me-
C
¼
O
E
,
Z
20.0
0.5
1.9
84
CDBr
3
[
115
,
171
,
185
]
a
C
¼
O
2,2
0
-di-
i
-PrO-
21.0
115
[
183
]
CH
2
2,2
0
-di-Me-
E
,
Z
23.8
0.3
3.8
159
CDBr
3
[
73
]
CH
2
2,2
0
-di-Me-
Inversion
23.4
0.5
41.2
198
C
4
Cl
6
[
73
]
Se, — 2
0
-
i
-Pr-
Inversion
14.4
29.4
14
CDCl
3
[
79
]
Se, — 2
0
-
i
-Pr-
E
,
Z
>
21.6
17.1
>
143
C
2
D
2
Cl
4
[
79
]
Te, — 2
0
-
i
-Pr-
Inversion
19.4
20.6
105
CDCl
3
[
79
]
Te, — 2
0
-
i
-Pr-
E
,
Z
>
21.6
17.8
>
143
C
2
D
2
Cl
4
[
79
]
a
E
,
Z
-Isomerization and conformational inversion
