Reaction Retrieval using Keywords

The second generation of reaction retrieval systems were more specifically tailored to the problem of efficient reaction retrieval, and specifically stored information relating to the atom-to-atom correspondences in going from reactants to products. Searches which made use of these correspondences were fast and essentially free from false drops. In addition these systems permitted extensive use of searches based on keywords or phrases, which are particularly useful when associated with a hierarchically structured thesaurus. 

In using a substructure approach, we determined that only 58% of the 138 citing papers would have been retrieved. Thus we observe that no single approach, reaction, substructure, cited reference, or keyword, would allow for complete retrieval of related papers and therefore a comprehensive search strategy must include multiple approaches. 

The use of selective reactions, in the sense that certain functionalities present in the reactant must not participate in/interfere with the desired reaction, is often needed. Retrieval is possible in all systems by specifying bonds as nonreaction centers . In CASREACT and DJSMONLINE this kind of restriction can also be entered via keywords (see Section 4.7). 

---