2'-O-Propargyl-G (iBu) CE Phosphoramidite

2'-O-Propargyl-G (iBu) CE Phosphoramidite is a click-handle RNA building block: 5'-O-(4,4'-dimethoxytrityl)-N2-isobutyryl-2'-O-(prop-2-yn-1-yl)guanosine 3'-O-(2-cyanoethyl N,N-diisopropyl)phosphoramidite. It is identified by CAS 171486-61-6, molecular formula C47H56N7O9P, molecular weight 894.0, PubChem CID 137126455, and InChIKey AGWGPRXHCUPJJO-VCGWOZLGSA-N.

The 2'-O-propargyl group is a permanent 2'-O-ether that carries a terminal alkyne (C≡CH) — it is not a protecting group. That terminal alkyne is a "click" handle: oligonucleotides bearing a terminal alkyne can be labeled after synthesis by the copper-catalyzed azide-alkyne cycloaddition (CuAAC) with azide-bearing reporters. The monomer couples through a standard 3'-phosphoramidite (3'→5' linkages), the 5'-DMT is removed each cycle, and the N2-isobutyryl base group is removed at final deprotection.