Mechanistic Investigation on Potassium Amide-Catalyzed Benzylic C–H Bond Addition of Alkylpyridines to Styrenes

The
catalytic C–H bond addition of alkylpyridines
to olefins
represents one of the most efficient approaches to alkyl-substituted
pyridine derivatives with 100% atom-economy efficiency. Various catalysts
including late transition metal, early transition metal, and s-block
metal complexes displayed rich and versatile activity. Potassium amide
could selectively achieve the benzylic alkylation of alkylpyridines,
displaying distinct activity and regioselectivity. Here, the mechanistic
investigation via both kinetic experiments and DFT calculations revealed
the dimer structure of potassium amide and confirmed alkylation via
a kinetic deprotonative functionalization process.