Match type

For duplicate and substructure type searches, the search results can be extended with the stereo and tautomer matches. For these extensions you just need to select the corresponding checkboxes.

Stereo matches

The duplicate search for structures is initiated considering the stereochemistry (tetrahedral stereo, double bond stereo, etc.) of the query and target structures. E.g. when searching for (1R)-1-phenylethan-1-ol only the duplicate of the query will be returned as a search result ( Figure: Duplicate search ).

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Duplicate search result

To extend the results with the stereo matches you need to select the Stereo matches checkbox. The result will return also the plain structure beside the (S)-enantiomer and also the structure with the "or" flag having an unknow configuration ( Figure: Extended Duplicate search ).

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Duplicate search result extended with stereo matches

Atropisomers can be searched by enabling the Stereo matches within Duplicate search.

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Atropisomers can be searched by enabling the Stereo matches within Duplicate search

Duplicate structures include CSTs

The matches involving CSTs (that are considered Different CST matches during submission or amendment) are displayed as 'Duplicate' search types on the Search page (Figure: Duplicate including CST)

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Duplicate search including CST

Tautomer matches

The search is performed by a JChem tautomer search, which includes lactim-lactam, keto-enol, imine-amine, and other common proton-shift tautomerism cases.
In the following example, a substructure search with keto-enol tautomer match is performed (Figure: Extended Substructure search).

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Substructure search extended with tautomer matches