Polymeric thiol-linked prodrugs employing benzyl elimination systems

A compound selected from the group consisting of

• R1—E1 (Ia)
• and
• 29
• wherein:
• R1 is a polymeric residue;
• Y1 is O, S or NR10;
• M is O, S or NR11;
• E1 is
• 30
• E2-4 is are independently H, E1 or
• 31
• (a) is zero or one;
• (m) is zero or a positive integer;
• (w) is zero or one;
• (n) and (p) are independently 0 or a positive integer;
• Y2-3 are independently O, S or NR12;
• R2-11 and R15 are independently selected from the group consisting of hydrogen, C1-6 alkyls, C3-12 branched alkyls, C3-8 cycloalkyls, C1-6 substituted alkyls, C3-8 substituted cycloalkyls, aryls, substituted aryls, aralkyls, C1-6 heteroalkyls, substituted C1-6 heteroalkyls, C1-6 alkoxy, phenoxy and C1-6 heteroalkoxy;
• D1 and D2 are independently OH,
• 32
• wherein:
• R′4 and R′5 are the selected from the same group which defines R4;
• and E35-38 are selected from the same group which defines E1-4 above, except that within the definition, D1 and D2 are changed to D′1 and D′2 which are defined below. Within this embodiment, D′1 and D′2 can be independently OH, a moiety of formula (IV) or (V), or
• 33
• wherein R″4 and R″5 are independently selected from the same group which defines R4 and E45-48 are selected from the same group which defines E1-4, except that within the definition D1 and D2 are changed to D″1 and D″2 and D″1 and D″2 independently OH, formula (IV) or formula (V);
• (v) and (t) are independently 0 or 1;
• L1 and L2 are independently selected heterobifunctional linkers;
• Y4-5 are independently selected from the group consisting of O, S and NR16;
• R12-14 and R16 are independently selected from the group consisting of hydrogen, C1-6 alkyls, C3-12 branched alkyls, C3-8 cycloalkyls, C1-6 substituted alkyls, C3-8 substituted cycloalkyls, aryls, substituted aryls, aralkyls, C1-6 heteroalkyls, substituted C1-6 heteroalkyls, C1-6 alkoxy, phenoxy and C1-6 heteroalkoxy;
• Ar is a moiety which when included in Formula (I) forms a multisubstituted aromatic hydrocarbon or a multi-substituted heterocyclic group;
• and
• B1 and B2 are preferably independently selected from among OH, and residues of sulfhydryl-containing moieties.