Scientists have long considered ketones (a fundamental chemical class) and esters (molecules formed when an acid reacts with an alcohol) to be locked treasure chests of possibilities. Ubiquitous as pharmaceutical intermediates, ketones and esters are widely used for the synthesis of drug molecules. Yet both share a critical limitation: Generally, only two specific sites within their structure -- the carbonyl carbon and the alpha position -- are easily accessible to conventional chemical reactions. The remaining carbon sites are protected by stable carbon-hydrogen (C-H) bonds that don't readily interact with catalysts -- substances that speed up chemical reactions and allow scientists to alter molecular structures. Thus, the C-H bonds make it difficult to modify ketones and esters. But now chemists have uncovered the key to unlocking these molecules' untapped potential.
