New linkers for solid phase organic chemistry. Multidirectional (multifunctional), backbone amide, and traceless linker

Solid phase organic chemistry is one of the key tools in combinatorial chemistry used to synthesize large libraries of new drugs and other biologically active compounds, especially in automated synthesis. With the aid of innovative linkers, capable of binding building blocks and intermediates as well as facilitating their ultimate release into solution, the synthetic gap between solid and liquid phase is diminished. Although the perfect or universal linker is not in sight and might prove unattainable, interesting new developments increase the flexibility of solid phase synthesis by traceless and multidirectional (Multifunctional, cleavage. While traceless linkers provide access to unsubstituted compounds with no memory of solid phase synthesis, multidirectional cleavage allows the introduction of various new functionalities during cleavage from the resin. Backbone amide linkers present new opportunities for solid phase synthesis of small amidic structures, Cyclization-release strategies provide an opporumity to create novel carbo-and heterocyclic structures upon cleavage.