Positioning of Functionalities in a Heteroduplex Major Groove: Synthesis of 7-Deaza-2-Amino-2′-deoxyadenosines

Abstract We have synthesized the 7-iodo-, 7-cyano-and 7-propynyl-7-deaza-2-ainino-2′-deoxyadenosines and incorporated each into several oligonucleotide (ODN) sequences. These oligonucleotides exhibit enhanced binding affinities to RNA complements relative to unmodified sequences.