N- trifluoroacetamide

A synthetic application of this reaction has been reported57 when the rearrangement of 2-aryl-O-phenylhydroxylamines is followed by a ring enlargement to give an aryldihy-droazepinone (Scheme 10). The 2-aryl-2-phenyl intermediate was also trapped out as the N-trifluoroacetamide. 

In the same manner, Walvoort et al. developed an automated synthesis of alginate tetramer 28, octamer 29 and dodecamer 30 through the use of mannuronate N-trifluoroacetamidate donor 27 as key building block, see Scheme 7. In this case, a high stereoselectivity was observed with the formation of 1,2-ds glycosidic bonds. 

The chirality of lissodinotoxin A, observed by NMR analysis of its N-trifluoroacetamide derivative, implies the existence of a new type of chirality due to a slow inversion of the pentathiepane ring the energy barrier is estimated at 29kcalmol (Searle and Molinski, 1994). 

---