conformations, respectively, in which the formers were syn isomers, while the latter
ones were trans isomers [19, 20].
For calix[1]triptycene[3]arenes 16–18, they adopted fixed cone conformation in
solution as well although they have bigger cavities than the classic calix[4]arene
[21]. For 16a, variable-temperature
1 H NMR experiments showed its coalescence
1b
DIPEA
CH 3 CN, reflux
OH
NH
N
H
N
N
N
N
N
N
Cl
Cl
Cl
Cl
O
O
N
H
NH
O
O
N
H
NH
50a, 37%
N
N
N
N
N
N
N
N
N
N
N
N
51a, 32%
+
Cl
Cl
Cl
Cl
O
O
N
H
NH
O
O
N
H
NH
O 2 N
NO 2
O 2 N
NO 2
O 2 N
NO 2
O 2 N
NO 2
+
NH
N
H
F
F
O 2 N
NO 2
O 2 N
NO 2
DIPEA
CH 3 CN, reflux
50b, 26%
51b, 21%
O
O
N
H
NH
O
O
N
H
NH
N
N
N
N
NC
CN
NC
CN
NC
CN
NC
CN
+
NH
N
H
N
N
Cl
Cl
NC
CN
NC
CN
DIPEA
CH3CN, reflux
50c, 32%
51c, 24%
OH
Scheme 10 Synthesis of triptycene-derived diazadioxacalixarenes 50 and 51
52a (26%)
HN
HN
N
O
O
NH
N
O
O
NH
HN
HN
N
O
O
NH
N
O
O
HN
+
NH 2
NH 2
43a
Et 3 N
THF,
0 °C to r.t.
N
ClOC
COCl
52b (20%)
+
Scheme 11 Synthesis of triptycene-derived tetralactam macrocycles 52
152
Y. Han and C.-F. Chen