Patent ID: 8551453

Claim:
A compound having the structure: wherein R 1 , R 2 , R 3 , R 4 , and R 6 are members independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heterocycloalkyl, wherein a member selected from R 1 and R 2 ; and R 3 and R 4 , together with the nitrogen atom to which they are attached, optionally form a ring system selected from heteroaryl and heterocycloalkyl; Y 1 , Y 2 and Y 3 are members independently selected from O and (H) 2 , wherein at least one group selected from Y 1 , Y 2 and Y 3 is O; Q is H; a protecting group and a cleavable group; L 2 is a member selected from substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocycloalkyl; L 3 , L 4 , L 5 and L 6 are members independently selected from a single bond, substituted or unsubstituted alkyl and substituted or unsubstituted heteroalkyl; and Z 2 , Z 3 , and Z 4 are members independently selected from H, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl.