Patent ID: 7560231

Claim:
A compound of the formula I, wherein Y is selected from the group consisting of O, S, and NR 4 , whereby R 4 is alkyl-, alkenyl, alkinyl, aryl-, acyl-, a protecting group or H, wherein X is a linking moiety in which n is 0 or 1, wherein R 1 is independent from R 2 , R 3 and R 4 , and wherein R 1 is selected from the group consisting of (1) a protecting group, (2) a label, and (3) a solid phase, wherein R 2 and R 3 are independent from each other and independent from R 1 or R 4 , and wherein R 2 and R 3 are selected from the group consisting of (1) —H, (2) a protecting group, (3) a solid phase and a linking moiety X, (4) a phosphoramidite, (5) a H-phosphonate, and (6) a triphosphate, with the proviso that R 3 but not R 2 can be triphosphate and R 1 is not a solid phase if R 3 is a triphosphate, with the proviso that R 2 and R 3 are not both a solid phase, not both a phosphoramidite, not both a H-phosphonate, not both —H or not both a protecting group, or not a phosphoramidite and a H-phosphonate, or not a solid phase and a phosphoramidite, or not a solid phase and a H-phosphonate, and with the proviso that when one residue selected from the group consisting of R 1 , R 2 or R 3 is a solid phase then the other two residues selected from the group consisting of R 1 , R 2 or R 3 are not a solid phase.