3666-84-0Relevant articles and documents
Development of a One-Pot Four C-C Bond-Forming Sequence Based on Palladium/Ruthenium Tandem Catalysis
Manick, Anne-Doriane,Berhal, Farouk,Prestat, Guillaume
supporting information, p. 194 - 197 (2018/01/17)
A one-pot four C-C bond-forming sequence has been developed using two distinct transition metal complexes. The sequence entails a double Pd-catalyzed allylic alkylation followed by a Ru-catalyzed ring-closing metathesis and a Pd-catalyzed Heck coupling. The use of various active methylene nucleophiles was examined with yields up to 76% (93% per C-C bond).
Palladium nanoparticles bonded to two-dimensional iron oxide graphene nanosheets: A synergistic and highly reusable catalyst for the Tsuji-Trost reaction in water and air
Liu, Jian,Huo, Xing,Li, Tianrong,Yang, Zhengyin,Xi, Pinxian,Wang, Zhiyi,Wang, Baodui
, p. 11549 - 11555 (2014/11/07)
Low cost, high activity and selectivity, convenient separation, and increased reusability are the main requirements for noble-metal-nanocatalyst- catalyzed reactions. Despite tremendous efforts, developing noble-metal nanocatalysts to meet the above requirements remains a significant challenge. Here we present a general strategy for the preparation of strongly coupled Fe3O4 and palladium nanoparticles (PdNPs) to graphene sheets by employing polyethyleneimine as the coupling linker. Transmission electron microscopic images show that Pd and Fe3O4 nanoparticles are highly dispersed on the graphene surface, and the mean particle size of Pd is around 3 nm. This nanocatalyst exhibits synergistic catalysis by Pd nanoparticles supported on reduced graphene oxide (rGO) and a tertiary amine of polyethyleneimine (Pd/Fe3O4/PEI/rGO) for the Tsuji-Trost reaction in water and air. For example, the reaction of ethyl acetoacetate with allyl ethyl carbonate afforded the allylated product in more than 99% isolated yield, and the turnover frequency reached 2200 h-1. The yield of allylated products was 66% for Pd/rGO without polyethyleneimine. The catalyst could be readily recycled by a magnet and reused more than 30 times without appreciable loss of activity. In addition, only about 7.5% of Pd species leached off after 20 cycles, thus rendering this catalyst safer for the environment. Picking up speed: A multifunctional Pd nanocatalyst was synthesized by in situ growth of palladium nanoparticles (PdNPs) and the assembly of Fe3O4 NPs on reduced graphene oxide (rGO) by employing polyethyleneimine as the coupling linker. This nanocatalyst exhibits synergistic catalysis by the amine on the same rGO surface as the PdNPs for acceleration of the Tsuji-Trost reaction in water and air (see figure).
Ruthenium-Catalyzed One-Pot Double Allylation/Cycloisomerization of 1,3-Dicarbonyl Compounds Leading to exo-Methylenecyclopentanes
Yamamoto, Yoshihiko,Nakagai, Yu-Ichiro,Itoh, Kenji
, p. 231 - 236 (2007/10/03)
The ruthenium-catalyzed one-pot double allylation/cycloisomerization of 1,3-diketones and methyl acetoacetate gave exo-methylenecyclopentanes in moderate to good yields with high isomer selectivity. The double allylation step effectively proceeded in the presence of a RuII precatalyst, [Cp*RuCl(cod)], in 1,2-dichloroethane at 90°C. The subsequent cycloisomerization was carried out upon addition of triethylsilane as a hydride source without purification of a 1,6-diene intermediate. Detailed inspections of the reaction by 1H NMR spectroscopy disclosed that triethylsilyl methyl ether plays an important role for the conversion of a ruthenium(IV) allyl complex formed in the double allylation step into a ruthenium(II) species required for the cycloisomerization.
