Active Iron(II) Catalysts toward <i>gem</i>-Specific Dimerization of Terminal Alkynes

We report the syntheses and catalytic activity of a series of piano-stool iron complexes with the general formula [FeClCp*­(NHC)] (where NHC = N-heterocyclic carbene) toward the gem-specific dimerization of terminal alkynes. In comparison to our first-generation catalyst, the newly synthesized catalyst is more active and features the same geminal specificity. Both the experimental and computational data are presented herein.