13562-84-0Relevant articles and documents
Combined experimental and computational studies of heterobimetallic Bi-Rh paddlewheel carboxylates as catalysts for metal carbenoid transformations
Hansen, Jorn,Li, Bo,Dikarev, Evgeny,Autschbach, Jochen,Davies, Huw M. L.
, p. 6564 - 6571 (2009)
(Chemical Equation Presented) The catalytic activity of heterobimetallic Bi-Rh paddlewheel carboxylate complexes has been evaluated for the first time in the context of metal carbenoid chemistry. The Bi-Rh carboxylate complexes were found to effectively catalyze both cyclopropanation reactions and C-H insertions as well as reactions involving ylide intermediates with similar selectivity profiles to analogous dirhodium complexes. The heterometallic complex BiRh(O2CCF3)3(O2CCH3) was found to be approximately 1600 times less reactive than its homometallic analogue Rh2(O2CCF3)3(O 2CCH3) toward the decomposition of methyl phenyldiazoacetate. The observed difference in reactivity is in good agreement with a computational model system where axial coordination to the second rhodium active site is considered for the dirhodium catalyst.
Studies of the Electronic Effects of Zinc Cluster Catalysts and Their Application to the Transesterification of β-Keto Esters
Agura, Kazushi,Hayashi, Yukiko,Wada, Mari,Nakatake, Daiki,Mashima, Kazushi,Ohshima, Takashi
supporting information, p. 1548 - 1554 (2016/06/01)
The electronic effects of tetranuclear zinc cluster catalysts on transesterification were investigated by changing the carboxylate ligands in the clusters. High catalyst activity crucially depended on the balance between Lewis acidity and Br?nsted basicity of the catalyst; this was consistent with the dual activation of both the electrophile and nucleophile by the cooperative zinc centers. In addition, tetranuclear zinc cluster catalysts achieved the transesterification of β-keto esters with unprecedented levels of broad substrate generality, in which a newly developed pentafluoropropionate-bridged zinc cluster and 4-dimethylaminopyridine additive greatly improved the reactivity of sterically congested α- and α,α-disubstituted β-keto esters. Lewis versus Br?nsted: High catalyst activity of zinc clusters on transesterification crucially depend on a balance between Lewis acidity and Br?nsted basicity of the catalyst. Zinc clusters, including a newly developed pentafluoropropionate-bridged zinc cluster, achieved the transesterification of β-keto esters with unprecedented levels of broad substrate generality (see figure).
Nano CuFe2O4: An efficient, magnetically separable catalyst for transesterification of β-ketoesters
Gohain, Mukut,Kumar, Vinod,Van Tonder, Johannes H.,Swart, Hendrik C.,Ntwaeaborwa, Odireleng M.,Bezuidenhoudt, Barend C. B.
, p. 18972 - 18976 (2015/03/04)
The preparation of a variety of β-ketoesters was achieved in high yields from methyl acetoacetate under neutral conditions through the utilization of magnetic CuFe2O4 nanoparticles as catalyst. Recycling of the catalyst was performed up to eight times without significant loss in activity. The catalyst was characterized using XRD, XPS, SEM and TEM techniques.
