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Synlett
Volumn , Issue 1, 2007, Pages 107-110
Synthesis of new Lewis basic room-temperature ionic liquids by monoquaternization of 1,4-diazabicyclo[2.2.2]octane (DABCO)
Author keywords

Alkyl halides; Amines; Green chemistry; Heterocycles; Ionic liquids
Indexed keywords

1,4 DIAZABICYCLO[2.2.2]OCTANE; IMIDAZOLE DERIVATIVE; IONIC LIQUID;
EID: 33846460419     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-2006-956460     Document Type: Article
Times cited : (32)
References (31)
  • 4
  • 5
    • 33748615410 scopus 로고    scopus 로고
    • This designation is widely used but has been challenged recently. See, for example: (a) Deetlefs, M, Seddon, K. R. Chem. Today 2006, 24, 16
    • This designation is widely used but has been challenged recently. See, for example: (a) Deetlefs, M.; Seddon, K. R. Chem. Today 2006, 24, 16.
  • 9
    • 33846409374 scopus 로고    scopus 로고
    • A SciFinder® search for 'ionic liquid' returns six hits for 1996 and 584 hits for 2005.
    • A SciFinder® search for 'ionic liquid' returns six hits for 1996 and 584 hits for 2005.
  • 11
    • 29244463334 scopus 로고    scopus 로고
    • Recent examples: (a) Lin, Y.-S.; Lin, C.-Y.; Liu, C.-W.; Tsai, T. Y. R. Tetrahedron 2006, 62, 872.
    • Recent examples: (a) Lin, Y.-S.; Lin, C.-Y.; Liu, C.-W.; Tsai, T. Y. R. Tetrahedron 2006, 62, 872.
  • 16
    • 33846416127 scopus 로고    scopus 로고
    • a2 = 8.82.
    • a2 = 8.82.
  • 19
    • 33846405191 scopus 로고    scopus 로고
    • in press; published online May 24
    • (a) Hu, Y.-F.; Xu, C.-M. Chem. Rev. 2006, in press; published online May 24, 2006.
    • (2006) Chem. Rev
    • Hu, Y.-F.1    Xu, C.-M.2
  • 21
    • 33846424860 scopus 로고    scopus 로고
    • Typical Procedure for Synthesis of Halide Salts. A solution of freshly sublimed DABCO (2.01 g, 17.8 mmol) in MeCN (20 mL) was prepared at r.t. under Ar in a flame-dried round-bottomed flask equipped with a reflux condenser. The resulting clear, colorless solution was treated with chloroheptane (1.37 mL, 8.96 mmol, added dropwise via syringe, and the reaction mixture was heated to 80 °C (sand bath temperature) and stirred for 22 h. After being cooled to r.t, the reaction mixture was transferred via cannula into 80 mL of Et 2O, yielding a white slurry which eventually separated into two layers. The whole was transferred to a separatory funnel, and the bottom layer was collected, washed repeatedly with Et2O and dried under high vacuum at 60 °C for 16 h to yield 1-heptyl-4-aza-1-azaniabicyclo[2.2.2] octane chloride (3e, 1.70 g, 77, as a white glassy solid, mp 110-111.5 °C. 1H NMR (300 MHz, CDCl3, δ, 3.66 t, J
    • 2]; negative ion mode, m/z (%) = 35 (100), 37 (44).
  • 22
    • 33846421296 scopus 로고    scopus 로고
    • All compounds were characterized by 1H NMR, 13C NMR, 19F NMR [for BF4, PF6 and N(SO 2CF3)2 salts] and 31P NMR (for PF6 salts) and LRMS ES
    • 6 salts) and LRMS (ES).
  • 23
    • 85164039893 scopus 로고    scopus 로고
    • Typical Procedure for Synthesis of Tetrafluoroborate Salts. A solution of 1-heptyl-4-aza-1-azaniabicyclo[2.2.2]octane chloride (3e, 0.402 g, 1.63 mmol) in MeCN (1.0 mL, prepared at r.t. under Ar in a flame-dried round-bottomed flask, was transferred via cannula to a slurry of NaBF 4 (0.181 g, 1.65 mmol) in MeCN (1.5 mL, A 0.5 mL MeCN rinse was used to ensure complete transfer. A white precipitate formed immediately and the resulting slurry was stirred at r.t. for 24 h. Filtration followed by concentration of the filtrate in vacuo yielded a colorless, viscous liquid. Drying under high vacuum at 60 °C for 3 d yielded 1-heptyl-4-aza-1- azaniabicyclo[2.2.2]octane tetrafluoroborate (4m, 0.458 g, 94, as a clear, glassy solid which was shown to be free of chloride contamination by a negative AgNO3 test; mp 64-66 °C. 1H NMR (300 MHz, CD3CN, δ, 3.21 (t, J, 7.2 Hz, 6 H, 3.12-3.05 (m, 8 H, 1.72-1.62 m
    • 11B. See: Hofstetter, C.; Pochapsky, T. C. Magn. Reson. Chem. 2000, 38, 90.
  • 24
    • 33846425257 scopus 로고    scopus 로고
    • Typical Procedure for Synthesis of Hexafluorophosphate Salts. A solution of 1-heptyl-4-aza-1-azaniabicyclo[2.2.2]octane chloride (3e, 0.398 g, 1.61 mmol) in MeCN (1.0 mL, prepared at r.t. under Ar in a flame-dried round-bottomed flask, was transferred via cannula to a slurry of NaPF 6 (0.275 g, 1.64 mmol) in MeCN (1.0 mL, A 0.5 mL MeCN rinse was used to ensure complete transfer. A white precipitate formed immediately and the resulting slurry was stirred at r.t. for 20 h. Filtration followed by concentration of the filtrate in vacuo yielded an oily, white solid shown to be contaminated with chloride by a positive AgNO3 test. The crude was partitioned between CH2Cl2 and H2O, and the CH2Cl2 layer was washed repeatedly with H2O until the aqueous layer gave a negative AgNO3 test. The CH 2Cl2 extract was dried Na2SO4, subjected to fi
    • 6].
  • 25
    • 33846445960 scopus 로고    scopus 로고
    • Typical Procedure for Synthesis of Bis(trifluoromethylsulfonyl)imide Salts. A solution of LiN(SO2CF3)2 (0.465 g, 1.62 mmol) in MeCN (1.0 mL, prepared at r.t. under Ar in a flame-dried round-bottomed flask, was transferred via cannula to a solution of 1-heptyl-4-aza-1-azaniabicyclo[2.2.2]octane chloride (3e, 0.396 g, 1.60 mmol) in MeCN (1.5 mL, A 0.5-mL MeCN rinse was used to ensure complete transfer. A white precipitate formed within 5 min and the resulting slurry was stirred at r.t. for 47 h. Filtration followed by concentration of the filtrate in vacuo yielded a colorless liquid shown to be contaminated with chloride by a positive AgNO3 test. The crude was partitioned between CH2Cl 2 and H2O, and the CH2Cl2 layer was washed repeatedly with H2O until the aqueous layer gave a negative AgNO3 test. The CH2Cl2 extract was dried Na2
    • 4], 282 (9).
  • 26
    • 33846446625 scopus 로고    scopus 로고
    • Yields are unoptimized
    • Yields are unoptimized.
  • 27
    • 33846440046 scopus 로고    scopus 로고
    • 3 tests.
    • 3 tests.
  • 28
    • 33846408582 scopus 로고    scopus 로고
    • All melting points were determined using samples sealed in evacuated tubes after drying in vacuo at 60 °C overnight and are uncorrected. For salts with melting points <25 °C, the sealed tubes and melting point apparatus were precooled to 5 °C in a cold room prior to melting point determination
    • All melting points were determined using samples sealed in evacuated tubes after drying in vacuo at 60 °C overnight and are uncorrected. For salts with melting points <25 °C, the sealed tubes and melting point apparatus were precooled to 5 °C in a cold room prior to melting point determination.
  • 29
    • 21844458908 scopus 로고    scopus 로고
    • Interestingly, the charge is delocalized onto the sulfur atoms but not, to a significant extent, onto the oxygen atoms in the bis(trifluoromethylsulfonyl)imide anion. This effectively shields the charge from the cation resulting in weaker interactions and lower melting points. See: Golding, J. J.; MacFarlane, D. R.; Spiccia, L.; Forsyth, M.; Skelton, B. W.; White, A. H. Chem. Commun. 1998, 1593.
    • Interestingly, the charge is delocalized onto the sulfur atoms but not, to a significant extent, onto the oxygen atoms in the bis(trifluoromethylsulfonyl)imide anion. This effectively shields the charge from the cation resulting in weaker interactions and lower melting points. See: Golding, J. J.; MacFarlane, D. R.; Spiccia, L.; Forsyth, M.; Skelton, B. W.; White, A. H. Chem. Commun. 1998, 1593.

* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.