Biology Reference
In-Depth Information
(1,4-bpbd) would yield the corresponding all-
-tetrakis(4-
pyridyl)-[3]-ladderane(4-tp-3-lad).Similarly,atemplated[2+2]
photodimerization of the triene
trans
-1,6-bis(4-pyridyl)-
1,3,5-hexatriene (1,6-bpht) would generate the corresponding all-
trans
trans,trans,trans
-tetrakis(4-pyridyl)-[5]-ladderane(4-tp-5-lad)(Scheme7.8).
O
H
N
O
H
N
N
H
O
O
O
N
H
O
O
O H
N
O H
N
O
N
H
O
H
O
N
hv
solid
hv
solid
O
O
H
H
N
N
N
N
H
H
O
O
O
O
O
O
O
H
O
H
N
N
N
N
O H
O H
Scheme 7.8
Wedetermined5-methoxy-resorcinol(5-OMe-res)asasuitable
template to generate both 4-tp-3-lad and 4-tp-5-lad in solids (Fig.
7.4)[26].Co-crystallizationof5-OMe-reswitheither1,4-bpbdor1,6-
bphtproducedthefour-componentassemblies2(5-OMe-res)·2(1,4-
bpbd)and2(5-OMe-res)·2(1,6-bpht),respectively.Ineachcase,
the C=C bonds of the polyenes were assembled and preorganized
in appropriate positions for reaction. UV irradiation of each solid
produced the targeted [3]- and [5]-ladderane in 100% yield. The
structuresoftheladderaneswereconfirmedviasingle-crystalX-ray
diffraction.
Figure 7.4
X-ray
structuresof(a)2(5-OMe-res)·2(1,4-bpbd),(b)4-tp-3-
lad,(c)2(5-OMe-res)·2(1,6-bpht),and(d)4-tp-5-lad.
 
Search WWH ::




Custom Search