2'-O-Propargyl-C (Ac) CE Phosphoramidite

2'-O-Propargyl-C (Ac) CE Phosphoramidite is a click-handle RNA building block: 5'-O-(4,4'-dimethoxytrityl)-N4-acetyl-2'-O-(prop-2-yn-1-yl)cytidine 3'-O-(2-cyanoethyl N,N-diisopropyl)phosphoramidite. It is identified by CAS 1498305-51-3, molecular formula C44H52N5O9P, molecular weight 825.9, PubChem CID 170899159, and InChIKey JIMYWWYYWAHJAD-ZMHKPELYSA-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 N4-acetyl base group is removed at final deprotection.