Preparation of Pyrene‐Modified Purine and Pyrimidine Nucleosides via Suzuki—Miyaura Cross‐Couplings and Characterization of Their Fluorescent Properties.

Abstract

A set of pyrene-modified pyrimidine and purine nucleosides, consisting of 5-(1-pyrenyl)-2'-deoxyuridine (1), 5-(1-pyrenyl)-2'-deoxycytidine (2), 8-(1-pyrenyl)-2'-deoxyguanosine (3), and 8-(1-pyrenyl)-2'-deoxyadenosine (4), was prepared via palladium-catalyzed Suzuki-Miyaura-type cross-coupling reactions. The syntheses started from 1-pyrenylboronic acid (5) and the corresponding halogenated nucleoside precursors. They were performed without protection of the hydroxy functions of the 2'-deoxyribose moiety and the exocyclic amino functions of the nucleoside bases. Good yields could be obtained for the preparation of 1 and 3, but not in case of 2 and 4. Obviously, the latter compounds require a protecting group strategy. The absorption and steady-state fluorescence properties of the pyrene-modified nucleosides 1-4 were characterized in MeCN and MeOH.