Tertiary combinatorial libraries

Combinatorial libraries of carbohydrates have been prepared by Patterson et al. [92] by attaching carbohydrates to polyallylamines. Mixtures of carboxylic acids and boric acid which was fluorescence-labeled with anthracene were coupled to polyallylamines. Boric acid served as the anchor position for the carbohydrates. Different receptors were attached to the polyallylamine backbone in close proximity to the boric acid anchors. If a carbohydrate was binding to the anchor unit, the fluorescence due to anthracene was increased. Moreover, if there was also interaction with the receptors, then fluorescence was quenched by photo-induced electron transfer (PET) of close tertiary amines.The response to N-acetylneuraminic acid was more intense than that to either glucose or fructose. 

Intelligent Design in Combinatorial Chemistry Use of Designed Peptide Libraries to Explore Secondary and Tertiary Structures in Peptides and Proteins... 

A simple example of using combinatorial chemistry to prepare a library of small molecules is the synthesis of secondary amides (9.46) from primary amines (9.44) and acid chlorides (9.45) (Scheme 9.4). Amides of type 9.46 have two points of variation the R-group of the amine and the R -group from the acid chloride. A third point of variation may be introduced by V- a I k y I ation with an alkyl halide (9.47) to form a tertiary amide (9.48). With just 15 building blocks—five amines, five acid chlorides, and five alkyl halides—125 (53) different tertiary amides may be prepared. 

---