A. C. Benniston et al. / Tetrahedron Letters 44 (2003) 2665–2667
2667
,
well separated (>5 A), and each is disordered over two
Chem. Commun. 1998, 265–266; Nishikido, J.; Inazu, T.;
Yoshino, T. Bull. Chim. Soc. Jpn. 1973, 46, 263–265;
Siepen, A.; Zett, A.; Vo¨gtle, F. Leibigs Ann. Chem. 1996,
757–760; Ashton, P. R.; Joachimi, D.; Spencer, N.; Stod-
dart, J. F.; Tscierske, C.; White, A. J. P.; Williams, D. J.;
Zab, K. Angew. Chem., Int. Ed. 1994, 106, 1503–1506.
sites. On the whole it appears that the cyclophane in the
solid state (and presumably in solution phase) is quite
mobile at the polyether chain and biphenyl group. The
,
,
overall cavity size of 2AI is ca. 10 A×3.5 A, which is
too small to accommodate a guest such as Na+ (r=0.95
A) or even Zn2+ (r=0.74 A) generated during the
7. Selected
analytical
data:
1,13-di-(3-nitrophenyl)-
13
13
,
,
1
synthetic procedure.
1,4,7,10,13-pentaoxatridecane (7): H NMR (CDCl3) l=
3.72 (m, 8H, CH2-CH2), 3.89 (m, 4H, CH2-CH2), 4.20 (m,
4H, CH2-CH2), 7.24 (ddd, 2H, J=8.3 Hz, J%=2.5 Hz,
J%%= 0.9 Hz, Ar-H6), 7.41 (t, 2H, J=8.2 Hz, Ar-H5), 7.75
(t, 2H, J=2.3 Hz, Ar-H2), 7.82 (ddd, 2H, J=8.1 Hz,
J%=2.1 Hz, J%%=0.9 Hz, Ar-H4). EI-MS m/z=436 (M+).
8. Computational studies on products and intermediates
were carried out using the commercial package Titan at
the semi-empirical AM1 level. Typically, a structure was
allowed to energy-minimise and converge, and a single-
point calculation carried out to determine the enthalpy of
formation.
That the reaction of 10 affords a product similar to 2A
suggests that the Na+ or Zn2+ ions do not, to any
significant extent, act as a template during molecular
rearrangement. It will be interesting to further test the
scope of the benzidine rearrangement by using other
extended polyether, alkyl and polyaza derivatives, as
this may lead to an alternative strategy for producing
new cyclophane hosts.
Supplementary material
9. Preliminary HPLC separations carried out on the mix-
tures suggest that products could be isolated on a prepar-
ative scale and fully identified.
Crystallographic data (excluding structure factors) for
the structure in this paper, have been deposited with the
Cambridge Crystallographic Data Centre as supple-
mentary publication number CCDC 199526. Copies of
the data can be obtained, free of charge, on application
to CCDC, 12 Union Road, Cambridge CB2 1EZ, UK
(fax: +44 (0)-1223-336033 or email: deposit@
ccdc.cam.ac.uk).
10. Analytical data:
6,9,12,15,18-Pentaoxa-tricylo[17.2.2.22,5]pentacosa-1(22),
2(25),3,5(24),19(23),20-hexaene-3,21-diamine (2A): 1H
NMR (CDCl3) l=3.00 (m, 8H, CH2-CH2), 3.63 (m, 4H,
CH2-CH2), 4.26 (m, 4H, CH2-CH2), 6.53 (d, 2H, J=2.3
Hz, Ar-H3), 6.64 (dd, 2H, J=8.4 Hz, J%=2.3 Hz, Ar-H5),
7.14 (d, 2H, J=8.4 Hz, Ar-H6). EI-MS m/z=374 (M+).
22,25 - Diiodo - 6,9,12,15,18 - pentaoxatricylo[17.2.2.2.2,5]-
pentacosa-1(22),2(25),3,5(24),19(23),20-hexaene
(2AI):
Acknowledgements
Yield 17%. 1H NMR (CDCl3) l=2.88 (m, 4H, CH2-
CH2), 3.18 (m, 4H, CH2-CH2), 3.61 (m, 4H, CH2-CH2),
4.17 (m, 2H, CH2-CH2), 4.47 (m, 2H, CH2-CH2), 7.09 (d,
2H, J=8.6 Hz, Ar-H6), 7.21 (dd, 2H, J=8.6 Hz, J%=2.4
Hz, Ar-H5), 7.58 (d, 2H, J=2.4 Hz, Ar-H3). EI-MS
m/z=596 (M+).
This work was supported by the Engineering and Phys-
ical Sciences Research Council (GR/23305/01). We
would also like to thank Mr. Sven Bornemann for
carrying out some preliminary work, and the EPSRC
Mass Spectrometry Facility at Swansea.
22,25-Iodonium-6,9,12,15,18-pentaoxatricyclo[17.2.2.2.2,5]-
pentacosa-1(22),2(25),3,5(24),19(23),20-hexaene
iodide
(2AII): Yield 24%. 1H NMR (d6-DMSO) l=2.27 (m, 2H,
CH2-CH2), 2.68 (m, 6H, CH2-CH2), 3.54 (m, 4H, CH2-
CH2), 4.33 (m, 4H, CH2-CH2), 7.53 (dd, 2H, J=8.6 Hz,
J%=2.2 Hz, Ar-H5), 8.06 (d, 2H, J=2.2 Hz, Ar-H3), 8.22
(d, 2H, J=8.6 Hz, Ar-H6) EI-MS m/z=596 (M+).
References
1. March, J. Advanced Organic Chemistry-Reactions, Mech-
anisms and Structure; 4th ed.; John Wiley & Sons: New
York, 1992; p. 1144.
2. Zhu-Ohlbach, Q.; Gleiter, R.; Gleiter, R.; Schmidt, H. L.;
Reda, T. Eur. J. Org. Chem. 1998, 11, 2409–2416.
3. Lee, B. W.; Lee, S. D. Tetrahedron Lett. 2000, 41, 3883–
3886.
11. The product from the Sandmeyer reaction using 5A was
identified as the iodonium salt 5AII (yield=31%). The
overall molecular structure however was similar in
appearance to that of the diiodide 2AI.
12. Orange single crystals of the diiodide of 2AI were grown
by layering a saturated solution of the compound in
CH2Cl2 with hexane. Selected X-ray crystallographic
4. Buncel, E.; Cheon, K. S. J. Chem. Soc., Perkin Trans. 2
1998, 1241–1247.
(
data: C20H22I2O5, M=596.2, triclinic, P1, a=9.5481(7),
5. Burguete, M. I.; Diaz, P.; Garc´ıa-Espan˜a, E.; Luis, S. V.;
Miravet, J. F.; Querol, M.; Ramirez, J. A. Chem. Com-
mun. 1999, 649–650.
6. A detailed search using SciFinder and Beilstein identified
several 4,4%-biphenol-based cyclophanes, but none with
only a polyether or alkyl strap. For other examples see:
Neumann, B.; Hegmann, T.; Wolf, R.; Tschierske, C.
Chem. Commun. 1998, 105–106; Abd-El-Aziz, A. S.; de
Denus, C. R.; Zaworotko, M. J.; Sharma, C. V. K.
,
b=9.8179(7), c=12.4608(9) A, h=111.987(2), i=
3
,
93.074(2), k=102.740(2)°, V=1044.43(13) A , Z=2, T=
160 K; R(F, F2>2|)=0.0362, Rw(F2, all data)=0.0907,
goodness of fit on F2=1.031, 337 parameters and 4904
−3
,
unique data, final difference map within 0.9 e A
.
13. Cotton, F. A.; Wilkinson, G. Advanced Inorganic Chem-
istry—A Comprehensive Edition; 4th ed.; John Wiley &
Sons, 1980; p. 14.