Combinatorial chemistry privileged structures

In recent years, developments in high-throughput screening inspired many pharmaceutical companies to focus and rely on combinatorial chemistry, especially massive parallel synthesis, to find new lead structures. The employed chemistry is often simple and the concept depends on sheer numbers for success. The main research areas were heterocyclic and peptide chemistry, and the resulting structures often lacked complexity and diversity, and most importantly the chance to utilize the evolutionary advantage of natural products with their privileged structures. 

Nicolaou KC, Pfefferkom JA, Mitchell HJ, Roecker AJ, Barluenga S, Cao GQ, Affleck RL, Lillig JE, Natural product-like combinatorial libraries based on privileged structures, 2, Construction of a 10,000-membered bcnzopyran library by directed split-and-pool chemistry using Nanokans and optical encoding, J. Am. Chem. Soc., 122 9954—9967, 2000. 

DeSimone, R.W., Currie, K.S., Mitchell, S.A., Darrow, J.W, and Pippin, D.A. (2004) Privileged structures applications in drug discovery Combinatorial Chemistry and High Throughput Screening, 7, 473-494. 

---