This page allows you to generate a virtual library of compounds that represent the products of the Ugi reaction. The reaction uses four reagents as shown in the figure below

This application makes use of a web service to process the individual reactants into a form which allows us to easily combine them into the final product molecules. Note, that increasing the number of each reagents can lead to very large numbers of products. If the resultant virtual library contains more than 2M compounds, this page will return an error. This limit will probably be increased later on.

Currently, the code assumes that each reagent has only one functional group that takes part in the reaction. So an acid should have a single COOH and an amine should have a single NH₂ group. Reagents that do not adhere to this are skipped. Also, make sure that the input SMILES do not have explicit hydrogens (this is due to a bug in the SMARTS parser, which should be fixed soon).

Though this page is specific to the Ugi reaction, the underlying code can be easily used to generate virtual libraries for any other reaction scheme.

Thanks to Jean-Claude Bradley and his work on the Ugi reaction for pushing me to make this page

NOTE: For some reason this page doesn't work with IE. So Firefox or Safari are the preferred browsers.