Heterocyclic CompoundsHeterocyclic Compounds, 2-RingHeterocyclic Compounds, 3-RingHeterocyclic Compounds, 1-RingAza CompoundsHeterocyclic Compounds, Bridged-RingNitrogen CompoundsCyclizationPalladiumMolecular StructureHeterocyclic Compounds with 4 or More RingsMagnetic Resonance SpectroscopyAzathioprineAzacitidineSulfur CompoundsVolatile Organic CompoundsStructure-Activity RelationshipSpiro CompoundsPlant ExtractsDrug Evaluation, PreclinicalSmall Molecule LibrariesDose-Response Relationship, Drug