Similar to our previous finding in an iron-catalysed hydrosilylation of olefins, 2 g there may be significant π–π interaction between the backbone of the 1,10-phenanthroline ligand and the aryl of the alkyne substrate, which leads the hydride to transfer to the alkyl substituent side of alkynes (as shown in the II-A model), and results in the observed regioselectivity.
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