Brønsted acid-catalyzed benzylation of 1,3-dicarbonyl derivatives

Organic Letters

Volumn 9, Issue 10, 2007, Pages 2027-2030

  Sanz, Roberto ^a   Miguel, Delia ^a   Martínez, Alberto ^a   Álvarez Gutiérrez, Julia M ^a   Rodríguez, Félix ^b  

^a UNIVERSITY OF BURGOS   (Spain)

^b UNIVERSITY OF OVIEDO   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 34249288620     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol070624a     Document Type: Article

References (30)

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8. Also, a surfactant-type Brønsted acid has been described as a catalyst for nucleophilic substitution of alcohols in water, see: Shirakawa, S.; Kobayashi, S. Org. Lett. 2007, 9, 311.
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16. This product has also been obtained as a byproduct in the metal triflate-catalyzed secondary benzylation of benzylic alcohols with different nucleophiles, see: Noji, M.; Ohno, T.; Fuji, K.; Futaba, N.; Tajima, H.; Ishii, K. J. Org. Chem. 2003, 68, 9340.
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21. 2 (3 mL). The reaction was stirred at reflux for 20 min (monitored by GC-MS). The solvent was removed under reduced pressure, and the residue was purified by silica gel chromatography (hexane/AcOEt, 15:1).
22. The use of other solvents like DMF and DMSO did not afford any substitution products. In THF, only bis(1-phenyl-ethyl) ether was obtained.
23. 2 gave rise to low yields of 3ad or 3af, respectively.
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27. This type of reaction course has also been proposed by different authors, see ref 5 and 9.
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30. Moderate yields are probably a reflection of the high tendency of the final products to polymerize under the workup or purification conditions.