(S)-Methyl2-(bis((2'-cyano-[1,1-biphenyl]-4-yl)methyl)amino)-3-methylbutanoate;Methyl bis((2'-cyano-[1,1'-biphenyl]-4-yl)methyl)-L-valinate;N,N-Bis[(2′-cyano[1,1′-biphenyl]-4-yl)methyl]-L-valine methyl ester ;