Patent ID: 7049432

Claim:
A compound of the structure: wherein each M 3 and M 4 independently, are OH, a protected hydroxyl, a linkage to a solid support, an activated phosphate group, an activated phosphite group, a reactive group for forming an internucleotide linkage, a nucleotide, a nucleoside, or an oligonucleotide; each J is, independently, hydrogen or a 2′-substituent group; R 6 is an electron withdrawing group or a group having the formula —(CH 2 ) n N(R 3 )(R 4 ); each R 3 and R 4 independently, are H, C 1 -C 10 alkyl or a nitrogen protecting group; each X 2 is hydrogen or —(CH 2 ) n —E 2 ; E 2 is hydrogen, alkyl, aryl, aralkyl, substituted aryl, a heterocycle, mixed heterocycle or heteroaryl; n is 1, 2, or 3; and Bx is a heterocyclic base moiety; wherein said electron withdrawing group is CN or NO 2 .