Patent ID: 8039642

Claim:
A compound having the formula: wherein R 1 and R 1′ are each H; X and X 1 are each O; s and t are independently selected from the integers from 0 to 3, with the proviso that at least one of s and t is at least 1; R 2 is a member selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heteroalkyl and substituted or unsubstituted heterocycloalkyl; R 3 is a member selected from substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, and substituted or unsubstituted heterocycloalkyl; and R 2 and R 3 , together with the nitrogen to which they are bound are joined to form a ring which is substituted with a reactive group, wherein said reactive group is a member selected from an acrylamide, an activated ester of a carboxylic acid, an acyl azide, an acyl nitrile, an aldehyde, an alkyl halide, an anhydride, an aniline, an aryl halide, an azide, an aziridine, a boronate, a carboxylic acid, a diazoalkane, a haloacetamide, a halotriazine, a hydrazine a hydrazide, an imido ester, an isocyanate, an isothiocyanate, a maleimide, a phosphoramidite, a reactive platinum complex, a sulfonyl halide, a thiol group, and a photoactivatable group.