Aminopyrimidine compounds and methods of their use

A compound of formula I:

• or a pharmaceutically acceptable salt thereof,
• wherein:
• Ar is a 6-10-membered aryl group or a 5-10-membered heteroaryl group, each optionally substituted;
• R1 is H, F, Cl, Br, C1-6alkyl, CN, C1-6haloalkyl, —C(O)NH2, —C(O)NH(C1-6alkyl), or —C(O)N(C1-6alkyl)2;
• R2 is a:
• 9-membered bicyclic heteroaryl comprising a 6-5-fused ring system wherein the 5-membered ring contains at least one nitrogen atom and the 6 membered ring is substituted with at least one E;
• or
• 13-membered tricyclic heteroaryl comprising a 6-5-6-fused ring system wherein the 5-membered ring contains at least one nitrogen atom and one of the 6 membered rings is substituted with at least one E;
• or
• 12- or 13-membered tricyclic group comprising a 5- or 6-membered cycloalkyl or heterocycloalkyl ring fused to a 9-membered bicyclic heteroaryl comprising a 6-5-fused ring system wherein the 5-membered ring contains at least one nitrogen atom and the 6 membered ring is substituted with at least one E;
• wherein E is an electrophilic moiety that is capable of reacting with a nucleophile so as to form a covalent bond between an atom of the nucleophile and an atom of the electrophilic moiety.