Combinatorial Chemistry Review

Carbamates and Amines Linker

Carbamates linker has been used for the synthesis of a combinatorial library of 576 polyamines prepared in the search of inhibitors of trypanosomal parasitic infections. Two linkers were investigated. One based on hydroxymethylbenzoic acid 1, and the other one, an electron-donating group has been added 2. The last one allowed cleavage by TFA while the first one could be cleaved with strong acidic conditions.

The two amine bearing linkers

A very useful linker has been recently developed for the generation of tertiary amine. (Tertiary amines are commonly used in drug molecules.) Primary and secondary amines are introduced to the linker by Michael addition. The amine may be alkylated to gives a resin-bound quaternary ammonium ion. In mildly basic condition, Hoffmann elimination occurs to give a tertiary amines of high purity.

The generation of tertiary amine by Hoffmann elimination