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Synlett
Volumn , Issue 1, 2007, Pages 146-150
DBU-mediated mild and chemoselective deprotection of aryl silyl ethers and tandem biaryl ether formation
Author keywords

Biaryl ether; Catalytic; Chemoselective; DBU; Desilylation
Indexed keywords

1,8 DIAZABICYCLO[5.4.0]UNDEC 7 ENE; 2 NAPHTHYL TERT BUTYLDIMETHYLSILYL ETHER; ACETIC ACID; AMIDINE; ESTER DERIVATIVE; FLUORIDE; SILANE DERIVATIVE; UNCLASSIFIED DRUG;
EID: 33846448754     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-2006-958425     Document Type: Article
Times cited : (45)
References (30)
  • 6
    • 19544377004 scopus 로고    scopus 로고
    • Representative examples on selective deprotection of silyl ether: (a) Kishore Kumar, G. D.; Baskaran, S. J. J. Org. Chem. 2005, 70, 4520.
    • Representative examples on selective deprotection of silyl ether: (a) Kishore Kumar, G. D.; Baskaran, S. J. J. Org. Chem. 2005, 70, 4520.
  • 19
    • 77957074554 scopus 로고
    • Katrizky, A. R, Ed, Academic Press Inc, New York, Chap. 42
    • (b) Hermecz, I. Advances in Heterocyclic Chemistry; Katrizky, A. R., Ed.; Academic Press Inc.: New York, 1987, Chap. 42, 83.
    • (1987) Advances in Heterocyclic Chemistry , pp. 83
    • Hermecz, I.1
  • 22
    • 33846423438 scopus 로고    scopus 로고
    • a Table (acidity in DMSO): http://chem.wisc.edu/areas/reich/pkatable (accessed July 2006).
    • a Table (acidity in DMSO): http://chem.wisc.edu/areas/reich/pkatable (accessed July 2006).
  • 23
    • 33846426356 scopus 로고    scopus 로고
    • David Evans research group:, accessed July 2006
    • (b) David Evans research group: http://daecrl.harvard.edu/pKa/pka.html (accessed July 2006).
  • 24
    • 37049068853 scopus 로고    scopus 로고
    • This trend corresponds to the report on the susceptibility of silylated cresols to basic hydrolysis, which was examined using 5% NaOH in 95% MeOH: Davies, J. S, Higginbotham, C. L, Tremeer, E. J, Brown, C, Treadgold, R. C. J. Chem. Soc, Perkin. Trans. 1 1992, 3043
    • This trend corresponds to the report on the susceptibility of silylated cresols to basic hydrolysis, which was examined using 5% NaOH in 95% MeOH: Davies, J. S.; Higginbotham, C. L.; Tremeer, E. J.; Brown, C.; Treadgold, R. C. J. Chem. Soc., Perkin. Trans. 1 1992, 3043.
  • 28
    • 33846464926 scopus 로고    scopus 로고
    • The nitro-substituted aryl fluorides were chosen as representative substrates, and we found that aromatic fluorides substituted with other electron-withdrawing groups, such as cyano or formyl, were also effective. The results will be described in a full account
    • The nitro-substituted aryl fluorides were chosen as representative substrates, and we found that aromatic fluorides substituted with other electron-withdrawing groups, such as cyano or formyl, were also effective. The results will be described in a full account.
  • 29
    • 33846405961 scopus 로고    scopus 로고
    • Cleavage of Aryl Silyl Ethers (Table 3, Entry 2, Typical Procedure: To a magnetically stirred solution of tertbutyldimethyl(2- naphthalenyloxy)silane (460 mg, 1.78 mmol) in anhyd MeCN (3.4 mL) and H 2O (0.18 mL) was added DBU (0.26 mE, 1.78 mmol, After the starting material disappeared (TEC, sat. aq NH4Cl solution (5 mE) was poured into the reaction mixture. The mixture was extracted with CH2Cl 2 (2 × 5 mL, and the organic layer was collected, dried over MgSO4, filtered, and concentrated under reduced pressure. The resulting residue was purified further by passing through a short silica gel column (ca 5 cm) and after vacuum evaporation pure 2-naphthol was obtained 250 mg, 98% yield, Desilylated position of bissilyl ether was determined by the chemical shift difference of the free alcohol or alkyl substituents on silicon in NMR. Generally, the chemical shifts of aryl alcohols are higher than those of the al
    • 13C NMR than those of aliphatic ones.
  • 30
    • 33846403636 scopus 로고    scopus 로고
    • Tandem, One-Pot Biaryl Ether Formation (Table 5, Entry 2, Typical Procedure: To a magnetically stirred solution of tert-butyldimethyl, 4-methoxyphenoxy)silane (410 mg, 1.73 mmol) in anhyd DMSO (3.5 mE) and H 2O (4 μL) were added p-fluoronitrobenzene (152 μL, 1.44 mmol, and DBU (13 μL, 0.173 mmol) sequentially at r.t. The mixture was heated to 80 0C, and the stirring was continued until the aryl fluoride disappeared on TEC. After completion of the reaction, the mixture was partitioned between Et 2O (5 mL) and brine (5 mL, and the organic layer was separated, dried over MgSO4, filtered, and concentrated under reduced pressure. The residue was purified through silica gel column chromatography (n-hexane-EtOAc, 6:1) to afford the desired pure biaryl ether 320 mg, 91% yield
    • 4, filtered, and concentrated under reduced pressure. The residue was purified through silica gel column chromatography (n-hexane-EtOAc = 6:1) to afford the desired pure biaryl ether (320 mg, 91% yield).

* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.