Carrier-protein polysaccharide conjugation methods

A method of preparing a heteroaryl-containing compound, the method comprising contacting an azide compound with an alkyne compound in the presence of lauryldimethylamine oxide (LDAO), water, and DMSO to form the heteroaryl-containing compound,

• wherein the LDAO is at a concentration of up to 2% v/v;
• wherein the azide compound is a compound of formula (I)
• wherein the alkyne compound is a compound of formula (II) or (III)
• wherein
• R1, R2, and R3 are independently selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, —(CH2)a—C(O)R1a, —(CH2)a—C(O) OR1a, —(CH2)a—C(O)N(R1a)2, —(CH2)a—C(O)NHCH(R1a)2, —(CH2)a—N(R1a)2;
• wherein a is integer from zero to 10;
• wherein each R1a is independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted heterocyclyl;
• or
• R1 is a first polypeptide comprising at least one non-natural amino acid residue (nnAAr) of formula (IV)
• wherein Z is absent or a 5-membered or 6-membered aryl or heteroaryl ring;
• W1 is selected from the group consisting of C1-C10 alkylene, —NH—, —O— and —S—;
• n is zero or 1;
• R8 is H or an amino acid residue of the first polypeptide, and R9 is OH or an amino acid residue of the first polypeptide;
• and
• R2 and R3 are independently -L1-X1;
• wherein
• X1 is a polysaccharide or a second polypeptide;
• L1 is optional, and when present is a linker selected from the group consisting of substituted or unsubstituted alkylene, substituted or unsubstituted alkenylene, —O—, —O-(substituted or unsubstituted alkylene)-, -(substituted or unsubstituted alkylene)-O—, —O-(substituted or unsubstituted alkylene)-C(O)—Y1—, —C(O)-(substituted or unsubstituted alkylene)-NH—Y2—, —C(O)-(substituted or unsubstituted alkylene)-C(O)—, —C(O)-(substituted or unsubstituted alkylene)-NH—C(O)—(CH2—CH2—O)n-(substituted or unsubstituted alkylene)-NH—, —C(O)-(substituted or unsubstituted alkylene)-NH—, —C(O)-(substituted or unsubstituted alkylene)-NH—C(O)—(CH2—CH2—O)n-(substituted or unsubstituted alkylene)-C(O)—, —C(O)-(substituted or unsubstituted alkylene)-C(O)—NH-(substituted or unsubstituted alkylene)-, —C(O)—, —C(O)-(substituted or unsubstituted alkylene)-, -(substituted or unsubstituted alkylene)-C(O)—, —C(O)N(RL1)—, —C(O)N(RL1)-(substituted or unsubstituted alkylene)-, -(substituted or unsubstituted alkylene)-C(O)N(RL1), -(substituted or unsubstituted alkylene)-C(O)NRL1-(substituted or unsubstituted alkylene)-, —OC(O)N(RL1)—, —OC(O)N(RL1)-(substituted or unsubstituted alkylene)-, -(substituted or unsubstituted alkylene)-OC(O)N(RL1)—, —N(RL1)C(O)—, —NRL1C(O)-(substituted or unsubstituted alkylene)-, -(substituted or unsubstituted alkylene)-NRL1C(O)—, —S—, —S-(substituted or unsubstituted alkylene)-, —S(O)k—, —S(O)k(alkylene or substituted alkylene)-, —C(S)—, —C(S)-(substituted or unsubstituted alkylene)-, —CSN(RL1)—, —CSN(RL1)-(substituted or unsubstituted alkylene)-, —N(RL1)C(O)O—, -(substituted or unsubstituted alkylene)-O—N═CRL1—, -(substituted or unsubstituted alkylene)-S(O)k-(substituted or unsubstituted alkylene)-S—, -(substituted or unsubstituted alkylene)-S—S—, —S(O)kN(RL1)—, —N(RL1)C(O)N(RL1)—, —N(RL1)C(S)N(RL1)—, —N(RL1)S(O)kN(RL1)—, —N(RL1)—N═, —C(RL1)═N—, —C(RL1)═N—N(RL1)—, —C(RL1)═N—N═, —C(RL1)2—N═N—, and —C(RL1)2—N(RL1)—N(RL1)—;
• wherein the bond on the left side of L1, as drawn, is bound to the 8-membered ring of the compound of formula (II) or the compound of formula (III) and the bond on the right side of the L1, as drawn, is bound to X1,
• Y1 is a bond, —NH—, —O—, —S—, —NH(Y1a)—, —O(Y1a)—, or —S(Y1a)—;
• Y2 is a bond, —C(═O)—, —S(═O)2—, —C(═O)Y2a—, —S(═O)2Y2a,
• Y1a and Y2a are each independently Y3 or Y3NH—
• Y3 is substituted or unsubstituted C1-10alkyl or —(CH2CH2O)1-10—;
• and
• n is an integer from 1 to 30;
• k is 1, 2, or 3;
• each RL1 is independently hydrogen or substituted or unsubstituted alkyl;
• and
• R4, R5, R6, and R7 are each independently hydrogen, halo, or substituted or unsubstituted alkyl.