Z‐Selective (Cross‐)Dimerization of Terminal Alkynes Catalyzed by an Iron Complex

Efficient iron-catalyzed homocoupling of terminal alkynes and cross-dimerization of aryl acetylenes with trimethylsilylacetylene is reported. The complex Fe(H)(BH4 )(iPr-PNP) (1) catalyzed the (cross-)dimerization of alkynes at room temperature, with no need for a base or other additives, to give the corresponding dimerized products with Z selectivity in excellent yields (79-99 %).