Fig. 7: Mechanistic investigations.

a Reductive cyclization of 1,7-enynes. b Reductive cyclization of alkenyl iodides. c Crossover experiment. d Stoichiometric experiment with aryl-Ni(II) complexes. e Quench of alkenylnickel intermediates. f Radical trapping experiment. TEMPO tetramethylpiperidine oxide. g Stoichiometric experiment with Ni(0). h Ring opening reaction. i Ring, closing reaction.