Herein we designed amino acid-based phosphorodiamidate (APdA) monomers bearing alkynyl moieties for subsequent thiol-yne photopolymerization. The good leaving group character of the amino acid was intended to increase the propensity to hydrolysis, with the α-substituent offering a handle to tune the hydrolysis rates through the steric hindrance of H2O. The alkyne-functionalized monomers (1 Ala-APdA and 2 Gly-APdA) were prepared by the simple Scheme 1: Monomer synthesis procedure. Conditions for 1, ACN, Ar, 50 °C 14h. For 2 and 3 THF, RT, Ar, 14h nucleophilic substitution of ethyldichlorophosphate with two equivalents of the respective amino acid alkynyl ester (Scheme 1). As a comparison, we also prepared the alkynyl phosphorodiamidate monomer 3 PdA, without an amino acid spacer via direct substitution of POCl2OEt with propargyl amine. The chemical structures and purity of the monomers were confirmed by 1 H, C, P NMR spectroscopy and mass spectrometry (see SI-1-12).