Method of synthesizing single-stranded nucleotide sequence, blocked nucleoside triphosphates and related methods

A method of synthesizing a single-stranded nucleotide sequence, the method comprising:

• (i) adding a blocked nucleoside triphosphate to an initiator nucleotide sequence to incorporate a corresponding blocked nucleotide thereto in the presence of a polymerase,
• wherein the blocked nucleoside triphosphate has one of the general formulae (I), (II), (III), (IV), (V) and (VI):
• wherein
• n=0 or 1;
• m=0 to 20;
• Rz is H or OH;
• R1, R2, R3, R4, R5, R6, Ra, Rb and Rc are each independently selected from hydrogen, alkyl, alkenyl, aryl and heteroaryl;
• R7 is selected from hydrogen, alkyl, halogen, —OR19, —NR20R21 and
• —SR22, wherein R19, R20, R21 and R22 are independently selected from hydrogen, alkyl, alkenyl, aryl and heteroaryl;
• R8, R9, R10, R11, R12, R13, R14, R15, R16, R17 and R18 are independently selected from hydrogen, alkyl, alkenyl, aryl and heteroaryl;
• X is a heteroatom selected from O, S and NH;
• Y1 and Y2 are independently selected from S and Se;
• and
• Z is a chemical moiety that is capable of being released under suitable conditions to trigger removal of the adjacent benzyl linker.