3-{[(tert-butoxy)carbonyl](2-phenylethyl)amino}propanoic acid

3-{[(tert-butoxy)carbonyl][(4-methylphenyl)methyl]amino}propanoic acid

tert-butyl 3-[(pentan-2-yl)amino]propanoate

tert-Butyl 3-(benzylamino)propanoate

tert-butyl 3-{[2-(piperidin-1-yl)ethyl]amino}propanoate

tert-butyl 3-[(2,2-dimethoxyethyl)amino]propanoate

tert-butyl 3-{[3-(1H-imidazol-1-yl)propyl]amino}propanoate

tert-butyl 3-[(diphenylmethyl)amino]propanoate

tert-butyl 3-{[3-(dimethylamino)-2,2-dimethylpropyl]amino}propanoate

ethyl 3-[(1-phenylethyl)amino]propanoate

ethyl 3-{[(pyridin-4-yl)methyl]amino}propanoate