Solution phase library synthesis

Abstract

Abstract Much of this book has so far described the synthesis of combinatorial libraries on solid phase. The benefit of preparing libraries on resin beads has been explained as offering advantages in handling, especially where there is a need to separate excess reagents from the reaction products attached to the resin. In most cases a simple filtration effects a rapid purification, and the products are ready for further synthetic transformation. But it should be remembered that using solid phase chemistry brings several disadvantages as well. Clearly the range of chemistry available on solid phase, although rapidly growing, is limited. Furthermore, it is much more difficult to monitor the progress of reactions when the substrate and product are attached to solid phase. Although methods are rapidly being developed to increase the range of solid phase chemistry, and there is an increasing use of IR and NMR techniques to characterize compounds whilst still attached to the solid phase, it is not inappropriate to ask whether all these difficulties could be simply avoided in the first place by using solution phase chemistry to prepare combinatorial libraries.