Multisensing emissive 8-phenylethynylated 2-deoxyadenosines and 2-deoxyisoguanosines

Microenvironment-sensitive fluorescent nucleosides are highly important for biotechnological applications. Here, we report the synthesis and photophysical properties of various new 8-phenylethynylated 2'-deoxyadenosines and 2'-deoxyisoguanosines. 8-phenylethynylated 2'-deoxyadenosines are synthesized using Sonogashira cross-coupling reaction (76-91%), which are further transformed to 8-phenylethynylated 2'-deoxyisoguanosines (50-63%). All new compounds exhibit strong solvatochromicity and pH-dependent fluorescence in aqueous solutions. Furthermore, 8-phenylethynylated purine analogues are sensitive to solvent viscosity changes, indicating their potential sensitivity to environmental changes. (C) 2019 Elsevier Ltd. All rights reserved.