Identifying lead hits in catalyst discovery by screening and deconvoluting complex mixtures of catalyst components† †Electronic supplementary information (ESI) available: Experimental procedures and spectral data. See DOI: 10.1039/c5sc00268k Click here for additional data file.

A reaction-economic combinatorial strategy is described for lead hit identification in catalyst discovery efforts directed towards a specific transformation. Complex mixtures of rationally chosen precatalysts and ligands are screened against various reaction parameters to identify lead conditions in a small number of reactions. Iterative deconvolution of the resulting hits identifies which components contribute to the lead in situ generated catalyst. Application of this strategy rapidly uncovered a new mild in situ generated catalyst for the dehydrative Friedel–Crafts reaction as well as conditions for selective monoarylation in catalytic ortho-C–H arylation of unsubstituted N-(quinolin-8-yl)benzamide.