1152-30-3Relevant articles and documents
Heterobimetallic Pd/Mn and Pd/Co complexes as efficient and stereoselective catalysts for sequential Cu-free Sonogashira coupling–alkyne semi-hydrogenation reactions
Baweja, Saral,Clauss, Reike,Gelman, Dmitri,Hey-Hawkins, Evamarie
, p. 1344 - 1356 (2022/02/03)
A series of heterobimetallic PdII/MII complexes (MII = Mn, Co) were synthesised and tested as precatalysts for sequential Sonogashira coupling–alkyne semi-hydrogenation reactions to form Z-aryl alkenes. The carbometalated heterobimetallic PdII/CoII complex CoPdL3′ demonstrated an apparent cooperative effect compared to the corresponding monometallic counterparts. This compound was identified as a potent single-molecule catalyst for the one-pot Cu-free Sonogashira coupling of aryl bromides with terminal alkynes followed by chemo- and stereoselective semi-hydrogenation of the alkyne intermediate using NH3·BH3 as a hydrogen source. Furthermore, different aromatic substrates have been tested to show the generality of the reaction for the synthesis of Z-alkenes, including biologically active combretastatin A-4. In addition, the homogeneous nature of the catalytically active species was demonstrated.
Valorisation of urban waste to access low-cost heterogeneous palladium catalysts for cross-coupling reactions in biomass-derived γ-valerolactone
Valentini, Federica,Ferlin, Francesco,Lilli, Simone,Marrocchi, Assunta,Ping, Liu,Gu, Yanlong,Vaccaro, Luigi
supporting information, p. 5887 - 5895 (2021/08/23)
Herein we report a simple protocol for the valorisation of a common urban biowaste. The lignocellulosic biomass obtained after the pre-treatment of pine needle urban waste is efficiently transformed into a low-cost support (PiNe) for the immobilization of Pd nanoparticles. The final Pd/PiNe heterogeneous catalyst features a small particle size (4.5 nm) and a metal loading (9.9 wt%) comparable with most commercially available and generally used counterparts. In this contribution, we tested the catalytic efficiency of the Pd/PiNe system in two representative cross-couplings, Heck and Hiyama reactions, and compared the results obtained with commercial Pd/C catalyst. The good reactivity in the biomass-derived solvent (GVL) confirms that the Pd/PiNe heterogeneous catalyst is a valid system that can be integrated into a waste valorization chain within a circular economy approach. In addition, the efficiency of the catalyst has also been extended to perform the challenging consecutive Hiyama-Heck reaction to afford differently substituted (E)-1,2-diarylethenes.
A Bidentate Ru(II)-NC Complex as a Catalyst for Semihydrogenation of Alkynes to (E)-Alkenes with Ethanol
Chen, Dafa,Gong, Dawei,Hu, Bowen,Kong, Degong,Xia, Haiping,Yang, Weiwei
, (2020/03/19)
Four Ru(II)-NC complexes were tested as catalysts for semihydrogenation of internal alkynes to (E)-alkenes with ethanol, and the complex {(C5H4N)(C6H4)}RuCl(CO)(PPh3)2 (1a) showed the highest activity. The reactions proceeded well with 1 mol % catalyst loading and 0.1 equiv of t-BuONa at 110 °C for 1 h, and 32 alkenes were synthesized with excellent E:Z selectivity. This is the first ruthenium-catalyzed semihydrogenation of internal alkynes to (E)-alkenes using ethanol as the hydrogen donor.
