From Amines to Alkynes – Lighting the Way

We present a metal-free photoredox strategy for the formation of Csp3-Csp bonds from redox-activated primary amine derivatives. The developed reaction of 2,4,6-triphenylpyridiniu salts with alkynyl tosylates, leading to functionalized alkynes , is easily scalable, offers broad substrate scope, high chemoselectivity, and mild conditions. Its potentials also highlighted by diversification of complex molecular scaffolds. Moreover, mechanistic studies contribute to the elucidation of unexpected differences in reactivity of primary, secondary and alkyl pyridinium salts.