Triflyl group replacement

Other imidoylnitrenes in which the cyano group is replaced by mesyl or triflyl groups were also prepared but failed to promote the ring expansion 1-arylisoureas were the only products.166... 

A series of imino-sugars with the imino group replacing the anomeric carbon atom have been prepared and tested as glycosidase inhibitors. Compound 45 was made from D-mannose via l,5-anhydro-4-C-hydroxymethyl-2,3-0-isopropyli-dene-L-ribofuranose. Compound 46 was also made from D-mannose via benzyl 2- C-benzyloxymethyl-2,3-isopropylidene-5-triflyl-a,P-D-lyxofuranose by successive treatment with azide, trifluoroacetic acid then hydrogenation-hydro-genolysis. ... 

Dihydrofuran and 3,4-dihydro-2//-pyran react with TfNs to afford A-triflylimino ethers (i.e. lactone A-triflylimines) (eq 8), whereas cyclohex-1-enol TMS ether is transformed into a triflylamide (eq 9). These reactions occur via path C, in the former case by a hydride shift and in the latter case by an alkyl shift leading to ring contraction. Open-chain silyl enol ethers, however, react via path D to A-triflyl a-amino ketones (eq 10). The yield drops to 28% upon replacement of the ferf-butyl by a phenyl group. 

The aryl groups in the triflyl oxamides were replaced by N-alkyl mor-phoUnium-or N-alkyl pyridinium residues as in (7) and (8) [9, 10] ... 

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