Synthesis of Alkyne‐ and Azide‐Modified Oligonucleotides and Their Cyclization by the CuAAC (Click) Reaction

Abstract The Cu(I)‐catalyzed alkyne‐azide cycloaddition (CuAAC) reaction has been used to synthesize cyclic mini‐DNA duplexes. The reaction is carried out on 5′‐alkyne‐3′‐azide‐labeled hairpin loop oligonucleotides and proceeds in high yield under mild conditions in as little as 5 min. The resultant duplexes have very high thermal stability and their CD spectra are characteristic of normal B‐DNA. Curr. Protoc. Nucleic Acid Chem . 35:4.33.1‐4.33.21. © 2008 by John Wiley & Sons, Inc.