Fast Co-Catalyzed Semihydrogenation of Alkynes with Controlled E/Z-Selectivity Using Same Catalyst

While several first-row transition metal catalysts are known to catalyze alkyne semihydrogenation, the selectivity is commonly controlled by the nature of the specialized catalyst, providing only E or only Z selectivity depending on the ligand/metal combination. In this work, E/Z selectivity control is described using the same pincer cobalt catalyst that allows to obtain either E or Z-semihydrogenation product with good to excellent selectivity and conversion controlled by reaction conditions.