(2S)-3-[4-(1-amino-3-methyliminoprop-1-en-2-yl)phenyl]-2-[[2-[1-[3-(4-ethoxyphenyl)propanoyl]piperidin-4-yl]acetyl]amino]propanoic acid;(2S)-2-[[2-[1-[3-(4-ethoxyphenyl)propanoyl]piperidin-4-yl]acetyl]amino]-3-(4-iodophenyl)propanoic acid;methyl (2S)-2-aminochloranuidyl-3-[4-(1-methylpyrazol-4-yl)phenyl]propanoate;methyl (2S)-2-(chloroamino)-3-(4-methylphenyl)propanoate;methyl (2S)-2-[[2-[1-[3-(3-fluorophenyl)propanoyl]piperidin-4-yl]acetyl]amino]-3-[4-(1-methylpyrazol-4-yl)phenyl]propanoate;methyl (2S)-3-(4-methylphenyl)-2-[(2-methylpropan-2-yl)oxycarbonylamino]propanoate;methyl (2S)-2-[(2-methylpropan-2-yl)oxycarbonylamino]-3-[4-(1-methylpyrazol-4-yl)phenyl]propanoate;bis(1-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazole)