Azide Solid Support for 3′-Conjugation of Oligonucleotides and Their Circularization by Click Chemistry

A solid support bearing an azido linker was used to synthesize a 3'-azido-alkyl-oligonucleotide by phosphoramidite chemistry. The resulting oligonucleotide was either conjugated by 1,3-dipolar cycloaddition on solid support or in solution with mannose-propargyl derivative and in solution with dansyl propargyl. Besides, after introduction of an alkyne function at the 5'-end, the resulting oligonucleotide hearing both 3'-azide and 5'-alkyne functions was circularized.