7-Deaza-7-iodo-2',3'-dideoxyadenosine is a modified nucleoside analog primarily used as a synthetic intermediate in biochemical research. The iodine substituent at the 7-position enables further chemical modifications, such as cross-coupling reactions, to generate diverse 7-substituted-7-deaza-dideoxyadenosine derivatives. These derivatives serve as tools for studying nucleic acid interactions, enzyme mechanisms, and DNA/RNA synthesis processes, often acting as chain terminators to halt nucleic acid chain elongation. This makes them valuable for DNA sequencing and investigating polymerase functions. Additionally, such analogs are employed in developing antiviral and anticancer agents by interfering with viral or tumor DNA replication, particularly targeting reverse transcriptase in RNA viruses. Researchers also use them to explore the impacts of nucleoside modifications on cellular metabolism and gene expression.