Wu Y,
Liu C,
Wang C,
Lu S,
Zhang B.
*
Tianjin University, P. R. of China
Selective Transfer Semihydrogenation of Alkynes with H
2O (D
2O) as the H (D) Source over a Pd–P Cathode.
Angew. Chem. Int. Ed. 2020;
59: 21170-21175
DOI:
10.1002/anie.202009757
Key words
electrocatalysis - semihydrogenation - alkynes - alkenes - palladium–phosphorus alloy
- deuteration
Significance
A Pd–P alloy nanoparticle network (Pd–P NN), prepared according to Equation 1, promoted
the selective electrocatalytic semihydrogenation of alkynes with H2O in aqueous 1,4-dioxane with 1.0 M KOH as an electrolyte to afford the corresponding
alkenes in up to 95% yield and 99% selectivity. When the reaction was performed in
1,4-dioxane–D2O, the corresponding di- and trideuterated alkenes were obtained with 99% deuterium
incorporation (Eq. 2). Monodeuterated alkenes were obtained by treatment of the alkynes
with 0.5 M K2CO3 in 1,4-dioxane–D2O, followed by the electrocatalytic semihydrogenation in aqueous 1,4-dioxane containing
a phosphate buffer (Eq. 3).
Comment
The Pd–P NN was characterized by means of SEM, TEM, EDX, XRD, XPS analyses. In the
electrocatalytic semihydrogenation of 4-ethynylaniline, the catalyst was reused five
times without significant loss of activity. The electrocatalytic semideuteration of
4-ethynylanisole was conducted on a gram scale to give 1.0 g of 1-(ethenyl-d
3)-4-methoxybenzene in 90% yield with 99% selectivity and 99% deuterium incorporation.
