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Download fileCyclophanes with Sharp Corners: Synthesis of Macrocycles Containing One or Two 1,5,2,4,6,8-Dithiatetrazocine Rings
journal contribution
posted on 1996-05-08, 00:00 authored by Steven Dell, Douglas M. Ho, Robert A. PascalSeveral cyclophanes have been prepared which contain
one or two of the bent 3,7-diamino-1,5,2,4,6,8-dithiatetrazocine (DTTA) ring systems linked by polymethylene chains:
1,8-dimethyl-1,8-diaza[8](3,7)(1,5,2,4,6,8-dithiatetrazocinophane) (6),
1,6,15,20-tetramethyl-1,6,15,20-tetraaza[6.6](3,7)(1,5,2,4,6,8-dithiatetrazocinophane)
(8), and
1,5,14,18-tetramethyl-1,5,14,18-tetraaza[5.5](3,7)(1,5,2,4,6,8-dithiatetrazocinophane)
(9). In each synthesis,
an N,N‘-dimethyl-α,ω-diamine was converted to
the corresponding bis(guanidinium hydrobromide), which
was
then treated with sulfur dichloride in the presence of DBU under
conditions of moderate dilution to form the
cyclophane in low yield (0.1−0.7%). When
N,N‘-dimethylhexanediamine was used, a cyclophane
containing a
single DTTA ring bridged by the polymethylene chain was formed
(6), but with the corresponding butane- and
propanediamines, dimeric cyclophanes containing a pair of DTTA rings
resulted (8 and 9). When
N,N‘-dimethylpentanediamine was used, a monomeric phane,
1,7-dimethyl-1,7-diaza[7](3,7)(1,5,2,4,6,8-dithiatetrazocinophane) (7), appeared to be formed, but it was not
isolated as a pure material. Compounds 6, 8,
and 9 were
characterized by X-ray crystallography. Crystallographic data:
for 6,
C10H18N6S2, monoclinic
P21/c, Z = 4,
a =
8.356(1) Å, b = 12.991(2) Å, c =
13.298(2) Å, β = 111.705(9)°; for 8,
C16H28N12S4·0.69CH2Cl2,
triclinic, P1̄,
Z = 2, a = 9.6095(8) Å, b
= 11.7085(11) Å, c = 13.2683(10) Å, α =
66.243(7)°, β = 82.340(6)°, γ =
73.989(7)°; for 9,
C14H24N12S4, triclinic
P1̄, Z = 2, a = 6.304(1)
Å, b = 8.366(1) Å, c = 21.357(3)
Å, α = 91.03(1)°,
β = 92.26(1)°, γ = 110.56(1)°. The dimeric
cyclophanes 8 and 9 were observed to form roughly
rectangular
troughs enclosing a small cavity, with the DTTA rings at two of the
corners. The DTTA ring of the monomeric
phane 6 was observed to be significantly distorted when
compared with the structures of less constrained DTTA's,
and ab initio calculations indicated that the phane 7, which
has a shorter bridge, but for which there is no X-ray
structure, is even more highly strained.