140863-27-0Relevant articles and documents
[(CH2=CH)2Al(μ-OCH2CH2NMe 2)]2: A vinylalane reagent suitable for conjugate additions to α,β-unsaturated ketones
Schumann, Herbert,Kaufmann, Jens,Dechert, Sebastian,Schmalz, Hans-Günter,Velder, Janna
, p. 5405 - 5408 (2001)
The reaction of AlCl3 with 2-dimethylaminoethanol in a 1:1 mole ratio yields [Cl2Al(μ-OCH2CH2NMe2)] 2 (1), which further reacts with two equivalents of vinylmagnesium chloride to give the divinylalane [(CH2=CH)2Al(μ-OCH2CH2NMe 2)]2 (2). Compound 2 was characterized by elemental analysis, 1H, 13C, and 27Al NMR spectra, mass spectrum and by X-ray structural analysis. Compound 2 was found to be a useful reagent for the transfer of a vinyl group to 1,3-diphenyl-2-propene-1-one (trans-chalcone). The 1,4-addition product is formed regioselectively, both in a non-catalyzed as well as in a nickel-catalyzed reaction.
Iridium-Catalyzed Enantioselective α-Allylic Alkylation of Amides Using Vinyl Azide as Amide Enolate Surrogate
Chakrabarty, Aditya,Mukherjee, Santanu
, p. 7752 - 7756 (2020/10/09)
Among the unstabilized enolates used as nucleophiles in iridium-catalyzed asymmetric allylic alkylation reactions, amide enolates are the least explored. Vinyl azides are now employed as amide enolate surrogates in Ir-catalyzed asymmetric allylic alkylation with branched allylic alcohols as the allylic electrophile. Competing reaction pathways are suppressed through the systematic tuning of the steric and electronic properties of vinyl azide to effect the α-allylic alkylation of secondary acetamides with high atom economy, exclusive branched selectivity, and mostly excellent enantioselectivity.
Rhodium-Catalyzed Branched and Enantioselective Direct α-Allylic Alkylation of Simple Ketones with Alkynes
Ma, Mingliang,Xie, Liyu,Xing, Dong,Yang, Haijian
supporting information, (2020/03/10)
Herein, we report the first direct branched-selective α-allylic alkylation of simple ketones with alkynes under rhodium and secondary amine cooperative catalysis. Through a rhodium-hydride-catalyzed allylic substitution pathway, a series of valuable γ,δ-unsaturated ketones are obtained with excellent regioselectivity in an atom-economic and byproduct-free manner. With a chiral BIPHEP ligand, high enantioselectivity has been achieved for this transformation.
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).
