Triflamides: new acylating and triflating reagents

✍ Scribed by James B. Hendrickson; Ray Bergeron

• Book ID: 104238620
• Publisher: Elsevier Science
• Year: 1973
• Tongue: French
• Weight: 190 KB
• Volume: 14
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)87289-0

✦ Synopsis

The trifluoromethanesulfonyl ("trifyl") group appears to be the most powerful electron-withdrawing group known and we have been examining this effect in a series of synthetic app1ications.I Triflation of nitrogen greatly enhances the potential of that atom to act as a stabilized anion leaving group, CF3S02N-(cf., CF3S02NH2, pKa = 5.8). Accordingly, we examined the behavior of N-triflated amides as acylating agents. These acylating agents may be prepared from amides by preforming the amide anion with sodium hydride (or tbutyl-lithium) in benzene and then adding triflic anhydride, (CF3S02) 20, at 5O c. The reaction is worked up by washing with aqueous acid and evaporation