A compound of Formula I: wherein: Y is —C(O)NHR1 or —NHC(O)R1; R1 is aryl;  is  optionally substituted with one or more substituents selected from the group consisting of oxo, F, Cl, Br, I, alkyl, NH2, NHR4, NHC(O)R4, NHC(O)OR4, NR5R6, OH, OR4, SR4, cycloalkyl and aryl; or  is  optionally substituted with one or more substituents selected from the group consisting of F, Cl, Br, I, CN, NO2, alkyl, C(O)R4, C(O)NHR4, C(O)NR5R6, C(O)OH, C(O)OR4, NH2, NHR4, NHC(O)OR4, NR5R6, OH, OR4, SR4, cycloalkyl and aryl; each R4 is independently alkyl, cycloalkyl, or aryl; each R5 is independently alkyl, cycloalkyl, or aryl; each R6 is independently alkyl, cycloalkyl, or aryl; or each R5 and R6, together with the nitrogen atom to which they are attached, independently form an unsubstituted heterocyclic alkyl or unsubstituted heterocyclic aryl; and X is —S— or —O—; and n is 2, 3, or 4.