New carbamate supports for the preparation of 3′-amino-modified oligonucleotides Original Research Article

A novel approach for the preparation of oligonucleotides carrying amino groups at the 3′-end is described. Several CPG supports having aminoalkyl groups and 3′-amino-2′, 3′-dideoxynucleosides linked through base-labile carbamate linkages such as 2-(2-nitrophenyl)ethoxycarbonyl and fluorenylmethoxycarbonyl were prepared using two different strategies. These supports are compatible to the standard solid phase phosphite-triester methodology and yield oligonucleotides containing amino groups at the 3′-end. Several properties of the 3′-amino oligonucleotides, such as nuclease resistance, hybridization, and preparation of oligonucleotide conjugates are discussed.