Asymmetric synthesis of aminopyrimidine and cyclic guanidine amino acids

Syntheses of amino acids with aminopyrimidine and cyclic guanidine side chains are described. The synthetic route employed Heck coupling of methyl 2-acetamidoacrylate to 4-methoxybenzyl protected 2-amino-5-iodopyrimidine, followed by Rh(I)-catalyzed asymmetric hydrogenation to afford a chiral protected amino acid. All protecting groups were removed under acidic conditions to afford the amino acid, (S)-2-amino-3-(2-aminopyrimidin-5-yl)propanoic acid, which underwent hydrogenation to afford an amino acid with a six-membered cyclic guanidine side chain.