Reducing agents and uses thereof

A method of making a compound of formula (A), wherein the compound of formula (A) has the formula:

• the method comprising mixing a compound of Formula (B) and a compound of Formula (C) together in a reaction vessel;
• wherein the compound of Formula (B) has the formula:
• wherein B is a nucleobase;
• L100 is a covalent linker;
• R100 is —OH, a monophosphate moiety, polyphosphate moiety, or nucleic acid moiety;
• R200 is —OH or hydrogen;
• R300 is a reversible terminator;
• L400 is a cleavable linker;
• and
• R500 is a detectable moiety;
• and
• and the compound of Formula (C) has the formula:
• wherein
• R1 is —W1-L1-R4;
• R2 is halogen or —W2-L2-R5;
• R3 is halogen or —W3-L3-R6;
• W1, W2, and W3 are independently —O—, —S—, or —NH—;
• L1, L2, and L3 are independently a bond, substituted or unsubstituted alkylene, substituted or unsubstituted heteroalkylene, substituted or unsubstituted cycloalkylene, substituted or unsubstituted heterocycloalkylene, substituted or unsubstituted arylene, or substituted or unsubstituted heteroarylene;
• R4 is
• R5 is hydrogen, —OH, NH2, —COOH, —CONH2, —SH, —SO3H, —SO4H, —SO2NH2, or
• R6 is hydrogen, —OH, NH2, —COOH, —CONH2, —SH, —SO3H, —SO4H, —SO2NH2, or
• and
• wherein R4A, R4B, R5A, R5B, R6A, and R6B are independently substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl.