Disclosed are compounds for SH2 domain binding inhibition. For example, disclosed is a compound of formula (I) ##STR1##

wherein R₁ is a lipophile; R₂, in combination with the phenyl ring, forms a phenylphosphate mimic group or a protected phenylphosphate mimic group; R₃ is hydrogen, azido, amino, carboxyalkyl, alkoxycarbonylalkyl, aminocarbonylalkyl, or alkylcarbonylamino, wherein the alkyl portion of R₃ may be optionally substituted with a substituent selected from the group consisting of halo, hydroxy, carboxyl, amino, aminoalkyl, alkyl, alkoxy, and keto; R₆ is a linker; AA is an amino acid; and n is 1 to 6; or a salt thereof. Also disclosed are a pharmaceutical composition, a method for inhibiting an SH2 domain from binding with a phosphoprotein and a method of treating breast cancer.