ABSTRACT
The biopolymer syntheses described in a following section involve the formation of a carbon-heteroatom bond (an amide bond for peptides, a glycosidic ether linkage for oligosaccharides, and a phosphate ester bond for oligonucleotides). While the ability to form these bonds is crucial to the synthesis of biopolymers, an expanded set of reactions is required to allow chemists to access more complex organic structures. A key tool for synthetic organic chemists is the ability to synthesize carbon-carbon (C-C) bonds. There are numerous methods available for the generation of C-C bonds in normal solution chemistry (which in most cases translate well to soluble polymer chemistry). However, these methods must often be modified for reactions in the presence of a solid support, where factors such as polymer solubility (or “swelling” ability), reagent solubility, and compatibility of any linker or previously existing functionality must be taken into
consideration. Extensive effort has gone into developing conditions for a variety of C-C bond-forming reactions on solid supports, a number of which are now available to the chemist for use in the parallel synthesis of small organic molecules [54]. Several examples of these reactions are shown below. Numerous other C-C bond-forming reactions have been described, including metal-mediated coupling reactions (such as Stille, Suzuki, and Heck reactions) [27] and multiple-component condensations (Passerini, Ugi, and Biginelli reactions, for example) [55]. Many of these other reactions are described briefly elsewhere in this chapter, and in-depth discussions can be found in several recent reviews of solid-phase synthesis [14,17,26,27,29,54,56].
