Imaging element containing a blocked photographically useful compound

An imaging element comprising an imaging layer having associated therewith a compound of Structure I:

• wherein
• PUG is a photographically useful group;
• LINK 1 and LINK 2 are linking groups;
• TIME is a timing group;
• 1 is 0 or 1;
• m is 0, 1, or 2;
• n is 0 or 1;
• T is a substituted or unsubstituted alkyl cycloalkyl, aryl or heterocyclic group, t is 0 to 2 and when t is 2, two T groups can combine to form a ring;
• U is halogen, hydroxy, or a substituted or unsubstituted amino, alkoxy, cyano, nitro, sulfono, amido or alkyl group, or T can combine with U to form a ring;
• u is 0 to 4 and when u is 2 to 4 two U groups can combine to form a ring;
• R4 and R5 are independently hydrogen, substituted or unsubstituted alkyl group or halogen;
• R4 and R5 can join to form a substituted or unsubstituted carbocycle or a heterocycle or R4 can join T to form a ring and R5 can join U to form a ring.