Synthesis solid supported mediated solution

Solid support mediated solution synthesis reagents... 

In an interesting development for combinatorial chemistry, Sm -promoted radical cyclizations have been adapted for use on solid support [27], The procedures developed have some inherent advantages over -Bu3SnH-mediated reactions and sometimes even to the corresponding solution phase SmE-promoted reactions. Unfortunately, they still appear to lack the consistency necessary for general use in the synthesis of chemical libraries. 

Supported reagents were further applied to achieve post-cleavage purification of products obtained by solid-phase synthesis. This is illustrated by an example from Ellman s laboratory Scheme 1.6.22). The p-tum mimetic precursor 43 was released from solid support by TCEP (41) mediated cleavage of a disulfid linkage. The polymeric guanidine 44 was used to remove excess of 41 and of the phosphinoxide 42, to promote formation of the cyclic sulfide 45, and to trap the byproduct HBr from solution. 

Solid-phase chemistry is an efficient synthetic tool that, compared with solution-phase chemistry, simplifies the work-up of the reaction, allows the process to be driven to completion by using excess of reagents, and can be automatized [2a]. In recent years, many studies have been devoted to developing both surface-mediated and resin-supported synthesis. Today the solid-phase approach is not limited to peptides and oligonucleotides but is also used to synthesize molecules of lower molecular weight. 

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