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Volumn 73, Issue 7, 2008, Pages 2598-2606

Calix[4]arene derivatives monosubstituted at all four methylene bridges

Author keywords

[No Author keywords available]

Indexed keywords

ALCOHOLS; DERIVATIVES; ISOMERIZATION; METHYLATION; OXYGENATION; REACTION KINETICS;

EID: 41649103747     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo702474n     Document Type: Article
Times cited : (46)

References (64)
  • 1
    • 0003433022 scopus 로고
    • For reviews on calixarenes see: (a) Vicens, J, Böhmer, V, Eds, Kluwer: Dordrecht
    • For reviews on calixarenes see: (a) Vicens, J., Böhmer, V., Eds. Calixarenes, a Versatile Class of Macrocyclic Compounds; Kluwer: Dordrecht, 1991.
    • (1991) Calixarenes, a Versatile Class of Macrocyclic Compounds
  • 5
    • 0004268367 scopus 로고    scopus 로고
    • Royal Society of Chemistry, Cambridge
    • (e) Gutsche, C. D. Calixarenes Revisited Royal Society of Chemistry, Cambridge, 1998.
    • (1998) Calixarenes Revisited
    • Gutsche, C.D.1
  • 6
    • 0004287470 scopus 로고    scopus 로고
    • Asfari, Z, Böhmer, V, Harrowfield, J, Vicens, J, Eds, Kluwer: Dordrecht
    • (f) Asfari, Z., Böhmer, V., Harrowfield, J., Vicens, J., Eds. Calixarenes 2001; Kluwer: Dordrecht, 2001.
    • (2001) Calixarenes 2001
  • 7
    • 0345736841 scopus 로고    scopus 로고
    • Rappoport, Z, Ed, Wiley: Chichester, Chapter 19
    • (g) Böhmer, V. In The Chemistry of Phenols; Rappoport, Z., Ed.; Wiley: Chichester, 2003; Chapter 19.
    • (2003) The Chemistry of Phenols
    • Böhmer, V.1
  • 14
    • 33748822682 scopus 로고    scopus 로고
    • For a review on the synthesis of calixarenes via the stepwise and fragment condensation methods see: Böhmer, V. Liebigs Ann./Recl. 1997, 2019
    • (g) For a review on the synthesis of calixarenes via the stepwise and fragment condensation methods see: Böhmer, V. Liebigs Ann./Recl. 1997, 2019.
  • 19
    • 0037244554 scopus 로고    scopus 로고
    • For a review on spirodienone calixarene derivatives see
    • (e) For a review on spirodienone calixarene derivatives see: Biali, S. E. Synlett 2003, 1.
    • (2003) Synlett , pp. 1
    • Biali, S.E.1
  • 22
    • 41649086614 scopus 로고    scopus 로고
    • The term classical designates calixarenes possessing bridging methylene groups connecting the phenol rings as opposed to thiacalixarenes (which possess sulfur bridges) azacalixarenes (nitrogen atoms, ketocalixarenes carbonyl groups, etc
    • The term "classical" designates calixarenes possessing bridging methylene groups connecting the phenol rings as opposed to " thiacalixarenes" (which possess sulfur bridges) "azacalixarenes" (nitrogen atoms), "ketocalixarenes" (carbonyl groups), etc.
  • 23
    • 20444457928 scopus 로고    scopus 로고
    • Azacalix[4]arenes substituted at several nitrogen bridges have been reported. See: (a) Tsue, H.; Ishibashi, K.; Takahashi, H.; Tamura, R. Org. Lett. 2005, 7, 2165.
    • Azacalix[4]arenes substituted at several nitrogen bridges have been reported. See: (a) Tsue, H.; Ishibashi, K.; Takahashi, H.; Tamura, R. Org. Lett. 2005, 7, 2165.
  • 30
    • 41649115302 scopus 로고    scopus 로고
    • 2 axis in the twist form of cyclohexane.
    • 2 axis in the twist form of cyclohexane.
  • 31
    • 41649083633 scopus 로고    scopus 로고
    • For a review on calix[4]arene systems functionalized at one or two bridges see: Simaan, S.; Biali, S. E. J. Phys. Org. Chem. 2004, 17, 752.
    • For a review on calix[4]arene systems functionalized at one or two bridges see: Simaan, S.; Biali, S. E. J. Phys. Org. Chem. 2004, 17, 752.
  • 34
    • 41649100752 scopus 로고    scopus 로고
    • A preliminary X-ray structure analysis of the molecule corroborated this structural assignment
    • A preliminary X-ray structure analysis of the molecule corroborated this structural assignment.
  • 37
    • 41649106141 scopus 로고    scopus 로고
    • Apparently, a mixture of isomers is obtained
    • Apparently, a mixture of isomers is obtained.
  • 38
    • 41649119446 scopus 로고    scopus 로고
    • A single crystal of 6e was grown from acetonitrile and submitted to X-ray crystallography. Although the structure could be refined only to a relatively high R factor (18 %), the structure corroborated the assigned rccc configuration of the macrocycle. The molecule adopts a cone conformation with the substituents located at equatorial positions and an acetonitrile molecule included in the cavity.
    • A single crystal of 6e was grown from acetonitrile and submitted to X-ray crystallography. Although the structure could be refined only to a relatively high R factor (18 %), the structure corroborated the assigned rccc configuration of the macrocycle. The molecule adopts a cone conformation with the substituents located at equatorial positions and an acetonitrile molecule included in the cavity.
  • 39
    • 7244238073 scopus 로고    scopus 로고
    • Hofmann, M.; Hampel, N.; Kanzian, T.; Mayr, H. Angew. Chem., Int. Ed. 2004, 43, 5402. See also:
    • (a) Hofmann, M.; Hampel, N.; Kanzian, T.; Mayr, H. Angew. Chem., Int. Ed. 2004, 43, 5402. See also:
  • 42
    • 41649117605 scopus 로고    scopus 로고
    • It is interesting to note that, although reflux of 2b in a 1:1 TFE/EtOH mixture yields exclusively 6b, heating in a 1:1 TFE/ethylene glycol mixture affords products containing both trifluoroethoxy and 2-hydroxyethoxy groups at the bridges. The lower relative nucleophilicity of the ethylene glycol molecules (as compared to that of EtOH) may be connected to the presence of inter- and intramolecular hydrogen bonds, as well as to the larger viscosity of the mixture.
    • It is interesting to note that, although reflux of 2b in a 1:1 TFE/EtOH mixture yields exclusively 6b, heating in a 1:1 TFE/ethylene glycol mixture affords products containing both trifluoroethoxy and 2-hydroxyethoxy groups at the bridges. The lower relative nucleophilicity of the ethylene glycol molecules (as compared to that of EtOH) may be connected to the presence of inter- and intramolecular hydrogen bonds, as well as to the larger viscosity of the mixture.
  • 44
    • 41649090468 scopus 로고    scopus 로고
    • When the reaction was conducted in TFE, a different isomeric mixture was obtained, the major form corresponding to the rctt isomer.
    • When the reaction was conducted in TFE, a different isomeric mixture was obtained, the major form corresponding to the rctt isomer.
  • 45
    • 41649086205 scopus 로고    scopus 로고
    • The SCN carbon of ethyl thiocyanate resonates at 112 ppm, while in isothiocyanates the carbon resonance is about ca. 20 ppm shifted downfield. See: Ben-Efraim, D. A. In The Chemistry of Cyanates and their Thio Derivatives, Part 1; Patai, S., Ed., Wiley: Chichester, 1977; Chapter 5, p 227.
    • The SCN carbon of ethyl thiocyanate resonates at 112 ppm, while in isothiocyanates the carbon resonance is about ca. 20 ppm shifted downfield. See: Ben-Efraim, D. A. In The Chemistry of Cyanates and their Thio Derivatives, Part 1; Patai, S., Ed., Wiley: Chichester, 1977; Chapter 5, p 227.
  • 46
    • 0001466110 scopus 로고
    • For selected examples of this transformation in macrocyclic rings see: a
    • For selected examples of this transformation in macrocyclic rings see: (a) Hart, H.; Takehira, Y. J. Org. Chem. 1982, 47, 4370.
    • (1982) J. Org. Chem , vol.47 , pp. 4370
    • Hart, H.1    Takehira, Y.2
  • 49
    • 41649091921 scopus 로고    scopus 로고
    • Without 1,2-butylene oxide an intractable mixture of products was obtained
    • Without 1,2-butylene oxide an intractable mixture of products was obtained.
  • 50
    • 41649087235 scopus 로고    scopus 로고
    • The complexity of the spectrum may be due to the presence of configurational isomers of the tetraaduct that adopt different conformations
    • The complexity of the spectrum may be due to the presence of configurational isomers of the tetraaduct that adopt different conformations.
  • 53
    • 41649101318 scopus 로고    scopus 로고
    • When the reaction was conducted with 2b, a mixture of trimethoxy and dimethoxy tetraxylyl derivatives was obtained. Since we were unable to fully methylate this mixture, we performed the reaction with the de-tert-butylated derivative 2a.
    • When the reaction was conducted with 2b, a mixture of trimethoxy and dimethoxy tetraxylyl derivatives was obtained. Since we were unable to fully methylate this mixture, we performed the reaction with the de-tert-butylated derivative 2a.
  • 54
    • 41649098935 scopus 로고    scopus 로고
    • Preliminary experiments indicate that reaction of 1b with excess HBr (50%) in HFIP (2 h reflux) affords the monodemethylated derivative (i.e., the trimethyl ether of p-tert-butylcalix[4]arene), while in TFE the demethylation proceeds further, and a mixture of the monomethyl ether and tetrahydroxycalixarene is obtained.
    • Preliminary experiments indicate that reaction of 1b with excess HBr (50%) in HFIP (2 h reflux) affords the monodemethylated derivative (i.e., the trimethyl ether of p-tert-butylcalix[4]arene), while in TFE the demethylation proceeds further, and a mixture of the monomethyl ether and tetrahydroxycalixarene is obtained.
  • 55
    • 0004323931 scopus 로고    scopus 로고
    • Tripos Inc, St. Louis, MO 63144
    • Alchemy 2000; Tripos Inc.: St. Louis, MO 63144, 2000.
    • (2000) Alchemy 2000
  • 56
    • 41649105367 scopus 로고    scopus 로고
    • Molecular mechanics calculations of 2a have been reported by Friedrichsen and coworkers (ref 8). These calculations were conducted assuming that each of the four forms (rccc, rcct, rctt, rctc) adopts a cone conformation. However, it was not examined whether in some substitution patterns the preferred conformation is different from cone.
    • Molecular mechanics calculations of 2a have been reported by Friedrichsen and coworkers (ref 8). These calculations were conducted assuming that each of the four forms (rccc, rcct, rctt, rctc) adopts a cone conformation. However, it was not examined whether in some substitution patterns the preferred conformation is different from cone.
  • 59
    • 41649112833 scopus 로고    scopus 로고
    • For a review on the conformation and stereodynamics of calixarenes see: Thondorf, I. in ref 1f, Chapter 15.
    • (c) For a review on the conformation and stereodynamics of calixarenes see: Thondorf, I. in ref 1f, Chapter 15.
  • 62
    • 41649102516 scopus 로고    scopus 로고
    • See also ref 3d
    • (b) See also ref 3d.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.