7-TFA-ap-7-Deaza-ddA  (5-TFA-ap-ddA)

7-TFA-ap-7-Deaza-ddG  (5-TFA-ap-ddG)

2’,3’-Dideoxy-5-[3-[(trifluoroacetyl)amino]-1-propynyl]-uridine  (5-TFA-ap-dU)

2’,3’-Dideoxy-5-[3-[(trifluoroacetyl)amino]-1-propynyl]-cytidine (5-TFA-ap-dC)