Catalytic Hydrogenations with Cationic Heteroleptic Copper(I)/N-Heterocyclic Carbene Complexes

Abstract

A new heteroleptic cationic copper(I) complex bearing two N-heterocyclic carbene (NHC) ligands has been prepared. In situ, a Cu–O­ bond can be generated which enables the complex to catalytically activate H2. The resulting complex shows activity in catalytic chemo- and stereoselective alkyne semihydrogenations as well as conjugate reductions of enones.

A ligand-free in situ-generated cobalt nanoparticle catalyst for (Z)-selective transfer semihydrogenation of alkynes

“…catalysts hindered their sustainability in chemical synthesis. Therefore, catalytic systems based on cheap metals, such as cobalt, [55][56][57] iron, [58][59][60][61] and copper, [62][63][64][65] have become a hot topic. Nevertheless, only a few catalytic systems have been reported for the transfer semihydrogenation of alkynes catalyzed by cobalt.…”

“…Early noble metal catalysts, such as gold, 43–47 ruthenium 48–51 and iridium 52–54 were utilized for the semihydrogenation of alkynes, but the high cost and limited reserves of noble metal catalysts hindered their sustainability in chemical synthesis. Therefore, catalytic systems based on cheap metals, such as cobalt, 55–57 iron, 58–61 and copper, 62–65 have become a hot topic. Nevertheless, only a few catalytic systems have been reported for the transfer semihydrogenation of alkynes catalyzed by cobalt.…”