A direct β-coupling of cyclic ketones with imines has been accomplished via the synergistic combination of photoredox catalysis and organocatalysis. Transient β-enaminyl radicals derived from ketones via enamine and oxidative photoredox catalysis readily combine with persistent α-amino radicals in a highly selective hetero radical-radical coupling. This novel pathway to γ-aminoketones is predicated upon the use of DABCO as both a base and an electron transfer agent. This protocol also formally allows for the direct synthesis of β-Mannich products via a chemoselective three-component coupling of aryl aldehydes, amines, and ketones.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4629778PMC
http://dx.doi.org/10.1021/jacs.5b05376DOI Listing

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