Magnesium trifluoromethanesulfonimide(triflimide) promoted substitution reactions of allylic and benzylic acetates. Magnesium triflimide as a substitute for magnesium perchlorate.

Tetrahedron Letters

Volumn 38, Issue 15, 1997, Pages 2645-2648

  Grieco, Paul A ^a   Handy, Scott T ^a  

^a INDIANA UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ACETIC ACID DERIVATIVE; CYCLOPENTANONE DERIVATIVE;

ARTICLE; CATALYSIS; DRUG SYNTHESIS; IN VITRO STUDY; METHODOLOGY; REACTION ANALYSIS;

EID: 0030975357     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(97)00441-3     Document Type: Article

References (7)

1. Grieco, P.A.; DuBay, W.J.; Todd, L.J. Tetrahedron Lett. 1996, 37, 8707.
2. Barbarich, T.J.; Handy, S.T.; Miller, S.M.; Anderson, O.P.; Grieco, P.A.; Strauss, S.H. Organometallics 1996, 15, 3776.
3. Treatment of a 0.1 M solution of p-methoxybenzyl acetate (1) in methylene chloride containing 10 mol% lithium cobalt-bis-dicarbollide with 2.0 equiv of silyl ketene acetal 2 afforded only recovered starting material after 120 h. Lithium tetrakis(1,1,1,3,3,3-hexafluoro-2-phenyl-2-propyloxy)aluminate, as well as lithium perchlorate and lithium triflimide, were equally ineffective.
4. Schumacher, J.C. Perchlorates: Their Properties, Manufacture, and Uses. Reinhold Publishing Corporation, New York, 1960.
5. Handy, S.T.; Grieco, P.A.; Mineur, C.; Ghosez, L. Synlett 1995, 565.
6. Magnesium triflimide can be readily prepared from bis(triflouromethanesulfonyl)imide and magnesium hydroxide. Prior to use, magnesium triflimide was dried under high vacuum at 150°C for 24 h. For an earlier study reporting the use of this salt as a catalyst for Diels-Alder reactions, see: Kobayashi, H.; Nie, J.; Sonoda, T. Chem. Lett. 1995, 307.
7. The following experimental procedure for the reaction between para-methoxybenzyl acetate (1) and silyl ketene acetal 2 serves as a general procedure. To a solution of para-methoxybenzyl acetate (31.2 mg, 0.17 mmol) in 2 mL of methylene chloride containing silyl ketene acetal 2 (82 mg, 0.34 mmol) under argon was added magnesium triflimide (11 mg, 0.0173 mmol). The heterogenous reaction was stirred at ambient temperature for 1 h. The reaction was quenched by the addition of water and the product isolated by extraction with methylene chloride. The combined organic extracts were dried with anhydrous magnesium sulfate and concentrated in vacuo. Flash chromatography using 10% ether/hexanes afforded 38.3 mg (99%) of adduct 3.