Ruthenium‐Catalyzed
<i>E</i>
‐Selective Partial Hydrogenation of Alkynes under Transfer‐Hydrogenation Conditions using Paraformaldehyde as Hydrogen Source
作者:Marcus N. A. Fetzer、Ghazal Tavakoli、Axel Klein、Martin H. G. Prechtl
DOI:10.1002/cctc.202001411
日期:2021.3.5
E‐alkenes were synthesized with up to 100 % E/Z selectivity via ruthenium‐catalyzed partial hydrogenation of different aliphatic and aromatic alkynes under transfer‐hydrogenation conditions. Paraformaldehyde as a safe, cheap and easily available solid hydrogen carrier was used for the first time as hydrogen source in the presence of water for transfer‐hydrogenation of alkynes. Optimization reactions showed
Ru‐Catalyzed Transfer Hydrogenation of Nitriles, Aromatics, Olefins, Alkynes and Esters
作者:Iryna D. Alshakova、Bulat Gabidullin、Georgii I. Nikonov
DOI:10.1002/cctc.201801039
日期:2018.11.7
preparation of new ruthenium(II) complexes supported by a pyrazole‐phosphine ligand and their application to transferhydrogenation of various substrates. These Ru complexes were found to be efficient catalysts for the reduction of nitriles and olefins. Heterocyclic compounds undergo transferhydrogenation with good to moderate yields, affording examples of unusual hydrogenation of all‐carbon‐rings
Tandem Acceptorless Dehydrogenative Coupling–Decyanation under Nickel Catalysis
作者:Siba P. Midya、Murugan Subaramanian、Reshma Babu、Vinita Yadav、Ekambaram Balaraman
DOI:10.1021/acs.joc.1c00592
日期:2021.6.4
reported. This unprecedented C═Cbond-forming methodology takes place in a tandem manner with the formation of formamide as a sole byproduct. The significant advantages of this strategy are the low-cost nickel catalyst, good functional group compatibility (ether, thioether, halo, cyano, ester, amino, N/O/S heterocycles; 43 examples), synthetic convenience, and high reaction selectivity and efficiency
Water as a Hydrogenating Agent: Stereodivergent Pd-Catalyzed Semihydrogenation of Alkynes
作者:Chuan-Qi Zhao、Yue-Gang Chen、Hui Qiu、Lei Wei、Ping Fang、Tian-Sheng Mei
DOI:10.1021/acs.orglett.9b00148
日期:2019.3.1
Palladium-catalyzed transfer semihydrogenation of alkynes using H2O as the hydrogen source and Mn as the reducing reagent is developed, affording cis- and trans-alkenes selectively under mild conditions. In addition, this method provides an efficient way to access various cis-1,2-dideuterioalkenes and trans-1,2-dideuterioalkenes by using D2O instead of H2O.
Rare-Earth Supported Nickel Catalysts for Alkyne Semihydrogenation: Chemo- and Regioselectivity Impacted by the Lewis Acidity and Size of the Support
作者:Bianca L. Ramirez、Connie C. Lu
DOI:10.1021/jacs.0c00905
日期:2020.3.18
iInitial rate studies were performed on the two tandem catalytic reactions separately: DPA hydrogenation and (Z)-stilbene isomerization. The catalytic activity in DPA hydrogenation follows the order: Ni-Ga > Ni-La > Ni-Y > Ni-Lu > Ni-Sc. By comparison, tThe ranking of catalysts by (Z)-stilbene isomerization initial rates is: Ni-Ga >> Ni-Sc > Ni-Lu > Ni-Y > Ni-La. In operando 31P and 1HNMRstudies revealed