A New Method for Amide Bond Formation

Possibly the most important condensation reaction is that between a carboxylic acid and an amine to give an amide. A great many methods are known by which this formal dehydration process may be carried out, almost all of which involve the two step sequence (i) activation of CO2H COX, where X is a leaving group and (ii) aminolysis of RCOX. Japanese workers have recently advocated the use of 2,2-dichloro-5-(2-phenylethyl)-4-trimethylsilyl-3-furanone (1, DPTF ) for carboxyl activation, and its use for peptide formation is illustrated by the representative conversion 2 — 3. The byproduct formed from DPTF in these reactions is 5-(2-phenylethyl)-4-trimethylsilylfuran-2,3-dione. 

Give a mechanistic explanation for the action of DPTF in such amide bond formation reactions. 

---