Enamine click chemistry libraries: Azides and terminal acetylenes

Enamine claims to be the "World largest collection of tangible building blocks and fragments for drug discovery". 

Related to click chemistry, the numbers of tangible structures for azides and terminal acetylenes are 3100 and 9200, respectively. These are estimated to be reliably and quickly synthesized as libraries.

A large existing library of Azides for click chemistry is available and has been used by researchers and companies alike. 

One could use acetylene libraries for screening of candidates. The selected ones could be reacted with azides libraries to create a pool for further screening. 

In other applications one may modify the molecule of interest with one of the above two functional groups and subject it to the other FG libraries for creating a library for further screening or property improvement.