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Synthesis of a Sulfur-bridged Calixarene

 

作者: Burkhard König,  

 

期刊: Journal of Chemical Research, Synopses  (RSC Available online 1997)
卷期: Volume 0, issue 3  

页码: 69-69

 

ISSN:0308-2342

 

年代: 1997

 

DOI:10.1039/a607416b

 

出版商: RSC

 

数据来源: RSC

 

摘要:

J. CHEM. RESEARCH (S), 1997 69 J. Chem. Research (S), 1997, 69 J. Chem. Research (M), 1997, 0556–0567 Synthesis of a Sulfur-bridged Calixarene Burkhard K�onig,*a Martin R�odel,a Ina Dixb and Peter G. Jonesb aInstitut f�ur Organische Chemie der Technischen Universit�at Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany bInstitut f�ur Analytische und Anorganische Chemie der Technischen Universit�at Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany A thiacalix[4]arene was obtained by the reaction of the 2,5-thiophene dianion with SCl2; the analogous reactions of dianions of diaryl thioethers did not yield macrocyclic structures and under the applied conditions diaryl sulfones were further deprotonated and the structure of the fourfold Me3Si-adduct 11 determined by X-ray crystallography.The first thiacalix[4]arene 8 was isolated in small amounts from the reaction of the 2,5-thiophene dianion with SCl2. Thiophene was deprotonated to the 2,5-dianion by treatment with BuLi–TMEDA.6 Slow addition of the biselectrophile SCl2 to a cold solution of the thiophene dianion gave, after work-up, a white solid.From the crude product a small amount of the thiacalix[4]arene 8 could be isolated. The thiophene moieties of the compound rotate freely on the NMR timescale in solution, as shown by simple NMR spectra. To increase the yield of the thiacalix[4]arene 8 a stepwise synthesis was investigated. However, the reaction was improved neither by the use of the thioether 96 nor the sulfone 10.5 In the latter case the regioselectivity of the deprotonation was lost, as illustrated by the formation of the tetrasilylated compound 11 upon treatment of the anion solution with Me3SiCl.The structure of 11 was confirmed by X-ray analysis.7 The thiophene units show an anti arrangement in the solid state and the geometry of the central sulfur atom is nearly ideal tetrahedral. Crystal Data.·C20H38O2S3Si4, monoclinic, a=1663.0(2), b=1055.0(0), c=1736.8(1) pm, b=103.89(1)°, V=2.958(2) nm3, space group P21/n, Z=4. The structure was solved by direct methods and refined anisotropically on F2, using the program SHELXL-93.7 Hydrogen atoms were included as rigid methyl groups or with a riding model.Final refinement with 274 parameters led to a final wR(F2) for all reflections of 0.084, S=0.934, with a conventional R(F) of 0.034; max. Dr 393 e nmµ3. A colourless prism ca. 0.64Å0.44Å0.42 mm was mounted on a glass fibre in inert oil.Measurements were performed on a Siemens P4 diffractometer with an LT-2 lowtemperature attachment at 173 K using graphite-monochromated Mo-Ka radiation (l=71.073 Å). 5196 independent reflections below 2y=50° were measured with the w-scan method. 3794 reflections with F0a4s(F0) were used in the structure solution and refinement.† We conclude that the reaction of dianions with SCl2 is less suitable for the synthesis of heteroatom-bridged macrocycles.Compared to Me2SiCl2,1 the reaction is less selective because of the high reactivity of the biselectrophile SCl2, yielding only small amounts of macrocycles. However, from the reaction of the 2,5-thiophene dianion and SCl2 the first thiacalix[4]arene 8 was isolated. Techniques used: 1H NMR, 13C NMR, MS, UV, IR, combustion analysis, X-ray diffraction References: 7 Schemes: 4 Table 1: Crystal data and structure refinement for 11 Table 2: Atomic coordinates and equivalent isotropic displacement parameters for 11 Table 3: Intramolecular bond distances and angles for 11 Appendix: 1H and 13C NMR spectra for compound 8 Received, 31st October 1996; Accepted, 19th November 1996 Paper E/6/07416B References cited in this synopsis 1 B.K�onig, M. R�odel, P. Bubenitschek and P. G. Jones, Angew. Chem., 1995, 107, 752; Angew. Chem., Int. Ed. Engl., 1995, 34, 661; B. K�onig, M. R�odel, P. Bubenitschek, P. G. Jones and I. Thondorf, J. Org. Chem., 1995, 60, 7406. 5 E. Jones and I. M. Moodie, Tetrahedron, 1965, 21, 2413. 6 L. Brandsma, Preparative Polar Organometallic Chemistry 1, Springer, Berlin, 1990; B. J. Wakefield, Organolithium Methods, Academic Press, London, 1988. 7 G. M. Sheldrick, SHELX-93, Program for Crystal Structure Refinement, University of G�ottingen, G�ottingen, Germany, 1993. *To receive any correspondence. †Atomic coordinates, bond lengths and angles, and thermal parameters are given in the full text and have also been deposited at the Cambridge Crystallographic Data Centre (CCDC). Any request to the CCDC for this material should quote the full literature citation and the reference number 423/3. Scheme 3 Scheme 4 Fig. 1

 



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