Synthesis of cyclopent-1-enecarbonitriles via a tandem Giese/HWE reaction initiated by visible light.

In the manuscript, a novel method for the preparation of cyclopent-1-enecarbonitriles via tandem Giese/HWE reaction initiated by visible light in the presence of fac -Ir(ppy) 3 as a photocatyst has been described. The cascade reactivity combining radical and polar processes has proven applicable for a wide range of N -(acyloxy)phthalimides (which serve as precursors of the corresponding radicals) as well as diethyl ( E )-(1-cyano-2-arylvinyl)phosphonates. The key parameters responsible for the success of the described strategy are: visible light, 1 mol% of photoredox catalyst, base, anhydrous solvent and inert atmosphere. The reaction results in new sp 3 -sp 3 and sp 2 -sp 2 carbon-carbon bonds formation under mild conditions.