A compound having a structure according to Formula I or II: wherein R 1a, R 1b, R 7a, and R 7b are independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heteroalkyl, and substituted or unsubstituted heterocycloalkyl; and R 1a and R 1b, together with the carbon atom to which they are attached, are optionally joined to form a ring which is a member selected from substituted or unsubstituted C 3 -C 7 cycloalkyl and substituted or unsubstituted 3- to 7-membered heterocycloalkyl; and R 7a, and R 7b, together with the carbon atom to which they are attached, are optionally joined to form a ring which is a member selected from substituted or unsubstituted C 3 -C 7 cycloalkyl and substituted or unsubstituted 3- to 7-membered heterocycloalkyl; wherein at least one of R 1a, R 1b, R 7a, and R 7b is not H; and R 8 is selected from H, wherein L x is selected from a bond, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heteroalkyl, and substituted or unsubstituted heterocycloalkyl; L xs is selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heteroalkyl, and substituted or unsubstituted heterocycloalkyl; R s is selected from a protected or unprotected reactive functional group, a linkage site, and a solid support; and R x is selected from a protected or unprotected reactive functional group and a linkage site; wherein each linkage site is covalently bound to a member independently selected from a nucleoside, a linker to a nucleoside, a nucleotide, a linker to a nucleotide, an oligonucleotide, a linker to an oligonucleotide, a nucleic acid, a linker to a nucleic acid, a carrier molecule, a linker to a carrier molecule, a solid support, and a linker to a solid support. R 1a, R 1b, R 7a, and R 7b are independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heteroalkyl, and substituted or unsubstituted heterocycloalkyl; and R 1a and R 1b, together with the carbon atom to which they are attached, are optionally joined to form a ring which is a member selected from substituted or unsubstituted C 3 -C 7 cycloalkyl and substituted or unsubstituted 3- to 7-membered heterocycloalkyl; and R 7a, and R 7b, together with the carbon atom to which they are attached, are optionally joined to form a ring which is a member selected from substituted or unsubstituted C 3 -C 7 cycloalkyl and substituted or unsubstituted 3- to 7-membered heterocycloalkyl; wherein at least one of R 1a, R 1b, R 7a, and R 7b is not H; and R 8 is selected from H, wherein L x is selected from a bond, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heteroalkyl, and substituted or unsubstituted heterocycloalkyl; L xs is selected from substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heteroalkyl, and substituted or unsubstituted heterocycloalkyl; R s is selected from a protected or unprotected reactive functional group, a linkage site, and a solid support; and R x is selected from a protected or unprotected reactive functional group and a linkage site;