Quaternary amino acids on solid supports

A compound of the following formula

• wherein
• Z comprises the residue of a solid polymer support having hydroxyl or amino functionality;
• L1 comprises a divalent group of the formula —O—, —NH—, —O—CH2—C6H4—CH2O—;
• L2 and L3 comprise, independently, alkylene, alkenylene, alkynylene, or a direct single bond;
• L4 comprises alkylene, —O—, —S—, —C(O)—, —S(O)—, —S(O)2—,
• or a direct single or double bond;
• L5 comprises —CH2CH2— or —CH2CH2CH2—;
• E and K comprise, independently, —N—, —CH—, or —C═;
• PG comprises hydrogen or an amino protecting group;
• R1 and R2 comprise, independently, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, heteroaryl, hydrogen, halo, —O—G3, —O—G4, —G3, —G4, or —N(G3)G4;
• R1 and R2 may be taken together to constitute a cycloalkyl or heterocyclyl ring, or, where L4 is a direct bond, R1 and R2 may be taken together to constitute a fused aryl or heteroaryl ring;
• G3 and G4 comprise, independently,
• where
• L7, L8, L9, L10, L11, L12 comprise, independently, alkylene, alkenylene, alkynylene, cycloalkylene, cycloalkenylene, arylene, heterocyclylene, heteroarylene, fused cycloalkylarylene, fused cycloakylheteroarylene, fused heterocyclylarylene, fused heterocyclylheteroarylene, or a direct bond;
• and
• R10, R11, R12, R13, R14, R15 comprise, independently, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocyclyl, heteroaryl, aryl, fused cycloalkylaryl, fused cycloakylheteroaryl, fused heterocyclylaryl, fused heterocyclylheteroaryl, —NR18R19, —OR18, —SR18, or hydrogen, where R18 and R19 are as defined below;
• R18 and R19 comprise, independently, hydrogen, alkyl, alkynyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, heterocyclyl, or heteroaryl.