posted on 2022-12-16, 15:44authored byDilip
K. Pandey, Eugene Khaskin, Shrinwantu Pal, Robert R. Fayzullin, Julia R. Khusnutdinova
We report an efficient semihydrogenation
of terminal alkynes with
H2, catalyzed by a modified, tetramethylated PNP pincer
Fe hydride complex. The reactivity contrasts with an analogous classical
PNP Fe hydride complex containing CH2 arms, which catalyzes
predominantly terminal alkyne dimerization even in the presence of
H2, and with an N-Me arm PNP Fe complex, which is known
to cause overreduction to alkanes and requires the presence of a trimethylsilyl
protective group. Such straightforward PNP ligand modification is
a convenient tool that switches reactivity and leads to selective
alkene formation, with no dimerization side products observed and
only a minor contribution from overreduction.