Asymmetric processes in the large-scale preparation of chiral drug candidates.

More than 50% of the 500 top selling drugs in the world today are single enantiomers. To address the production of enantiomerically pure drug candidates, several tools (chiral pool, asymmetric catalysis, chiral reagents, chiral auxiliaries, resolution and biotransformation) are becoming increasingly available to the process chemist for development and large-scale manufacturing. This article will document salient examples from the post-1998 literature that, in the opinion of the authors, best exemplify the utilization of these tools by process chemistry groups throughout the pharmaceutical industry.