Chemical Labeling of 5-Iodo-2′-deoxyuridine with 4-Ethynyl-N-ethyl-1,8-naphthalimide Using Copper-Free Sonogashira Cross-Coupling in Aqueous Medium

Abstract

The utility of Sonogashira cross-coupling reactions in organic synthesis is indisputable. However, the palladium catalytic Sonogashira reaction in mild condition is still in its infancy. Here, we reported the synthesis of a fluorescent nucleoside analog by using a copper-free Sonogashira cross-coupling reaction in a satisfactory yield. This reaction occurred at 37 °C in the open air and aqueous medium, and avoided the toxicity of Cu(I). The mild Sonogashira reaction provided the possibility of fluorescent labeling of nucleoside mimics in living cells.

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GRAPHICAL ABSTRACT

Keywords:

• Aqueous medium
• copper-free
• nucleoside analogs
• Sonogashira reaction