Compounds for cancer chemotherapeutic sensitization

A compound of formula (I), (II) or (III):

• wherein:
• R1 is phenyl, benzyl or (C1-C3)alkyl optionally substituted with halo, wherein the phenyl or benzyl is optionally substituted with one or more groups Rx that are independently selected from the group consisting of halo, carboxy, (C1-C6)alkoxycarbonyl, halo(C1-C6)alkoxycarbonyl, —C(═O)NRbRc, —NHP(═O)(ORd)(ORe), —NHC(═O)ORf, —B(ORg)(ORh), —S(O)2F, —P(═O)(F)(ORk),
• and (C1-C3)alkyl substituted with halo, (C1-C6)alkoxycarbonyl, halo(C1-C6)alkoxycarbonyl, —C(═O)NRbRc, —NHP(═O)(ORd)(ORe), —NHC(═O)ORf, —B(ORg)(ORh), —S(O)2F, or —P(═O)(F)(ORk);
• Rb and Rc are each independently H or (C1-C6)alkyl;
• Rd and Re are each independently H, (C1-C6)alkyl, or phenyl;
• Rf is H, (C1-C6)alkyl, or phenyl;
• Rg and Rh are each independently H or (C1-C6)alkyl, or Rg and Rh taken together with the boron to which they are attached form a 5- or 6-membered ring that is optionally substituted with one or more groups independently selected from (C1-C6)alkyl;
• Rk is (C1-C6)alkyl;
• and
• Rmn is H, (C1-C6)alkyl, or phenyl;
• R2 and R3 are each independently selected from H, halo or (C1-C6)alkyl that is optionally substituted with halo;
• R4 is phenyl, wherein the phenyl is optionally substituted with one or more groups Rxx that are independently selected from the group consisting of halo, carboxy, —OH, —ORl, (C1-C6)alkoxycarbonyl, halo(C1-C6)alkoxycarbonyl, —C(═O)NRmRn, —NHP(═O)(ORp)(ORq), —NHC(═O)NRmRn, —NHS(O)2Rss, —B(ORt)(ORtt), —S(O)2F, —P(═O)(F)(ORv),
• and (C1-C3)alkyl optionally substituted with halo, (C1-C6)alkoxycarbonyl, halo(C1-C6)alkoxycarbonyl, —C(═O)NRmRn, —N—P(═O)(ORp)(ORq), —NHC(═O)ORs, —B(ORt)(ORtt) —S(O)2F, or —P(═O)(F)(ORv);
• Rm and Rn are each independently H or (C1-C6)alkyl;
• Rp and Rq are each independently H, (C1-C6)alkyl, or phenyl;
• Rs is H, (C1-C6)alkyl, or phenyl;
• Rss is (C1-C6)alkyl, or phenyl;
• Rt and Rtt are each independently H or (C1-C6)alkyl, or Rt and Rtt taken together with the boron and oxygens to which they are attached form a 5- or 6-membered ring that is optionally substituted with one or more groups independently selected from (C1-C6)alkyl;
• Rv is (C1-C6)alkyl;
• and
• R5 is (C1-C6)alkyl or phenyl, wherein the alkyl or phenyl is optionally substituted with one or more groups that are independently selected from the group consisting of halo, (C1-C6)alkoxycarbonyl, —NHP(═O)(ORw)(ORy), —C(═O)NRzRaa, —NHC(═O)ORbb, carboxy, or (C1-C3)alkyl substituted with —NHP(═O)(ORw)(ORy);
• Rz and Raa are each independently H or (C1-C6)alkyl;
• Rw and Ry are each independently H, (C1-C6)alkyl, or phenyl;
• and
• Rbb is H, (C1-C6)alkyl, or phenyl;
• or a salt thereof.