Searching the Chemical Literature by Structure and by Reaction
Chemical searching is not keyword searching. A structure or substructure query finds compounds regardless of what they were called, and a reaction query finds precedent for a transformation, which is what tells you whether a planned step has ever worked.
What a learner can do afterwards
- Turns a planned step into a reaction query with the right level of generality
- Uses a substructure search to find precedent for a scaffold and narrows it sensibly
- Traces a reported procedure back from a review to the paper that first published it
- Judges whether a hit is real precedent or a superficially similar case
1 · Read
Chemical searching is not keyword searching. A structure or substructure query finds compounds by drawing, whatever they were called. A reaction query finds precedent for a transformation, which tells you whether a planned step has ever worked.
You plan a coupling on a heterocycle your group never used. Draw the ring as a substructure and the bond change as a reaction query, keeping the groups general. Too many hits means narrow toward your ring and substituents, and a null result means no precedent, not proof it fails.
A review never counts as the procedure. Trace its citation back to the paper that first published the reaction, and read the exact conditions there.
Judge each hit on the reacting atoms and their electronics. Same atoms with similar electronics is real precedent, while a similar name with a different mechanism is decoration.
Draw the query, tune its generality, trace hits to the first paper, and judge by reacting atoms.
2 · Watch
Take it off screen
Where it sits
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.