Base catalytic activity of alkaline earth MOFs: a (micro)spectroscopic study of active site formation by the controlled transformation of structural anions
作者:P. Valvekens、D. Jonckheere、T. De Baerdemaeker、A. V. Kubarev、M. Vandichel、K. Hemelsoet、M. Waroquier、V. Van Speybroeck、E. Smolders、D. Depla、M. B. J. Roeffaers、D. De Vos
DOI:10.1039/c4sc01731e
日期:——
The selective decomposition of structural nitrate anions in alkaline earth MOFs generates highly dispersed base sites with catalytic applications.
Synergistic Noncovalent Catalysis Facilitates Base-Free Michael Addition
作者:Jianzhu Wang、Tom A. Young、Fernanda Duarte、Paul J. Lusby
DOI:10.1021/jacs.0c08639
日期:2020.10.14
Carbon-Carbon bond forming processes that involve the deprotonation of a weakly acidic C-H pro-nucleophile using a strong Brønsted base are central to synthetic methodology. Enzymes also catalyze C-Cbondformation from weakly C-H acidic substrates, however, they accomplish this at pH 7 using only collections of non-covalent interactions. Here we show that a simple, bio-inspired synthetic cage catalyzes
The Michael additions of activatednitriles to methyl acrylate (MA) and methyl vinyl ketone (MVK) proceeds with fair to high yields (46–92%) in the presence of catalytic amount of HRh(CO)(PPh3)31 under mild eaction conditions.
Metal-dioxidoterephthalate MOFs of the MOF-74 type: Microporous basic catalysts with well-defined active sites
作者:Pieterjan Valvekens、Matthias Vandichel、Michel Waroquier、Veronique Van Speybroeck、Dirk De Vos
DOI:10.1016/j.jcat.2014.06.006
日期:2014.8
The hybrid frameworks M(2)dobdc (dobdc(4-) = 2,5-dioxidoterephthalate, M2+ = Mg2+, Co2+, Ni2+, Cu2+ and Zn2+), commonly known as CPO-27 or MOF-74, are shown to be active catalysts in base-catalyzed reactions such as Knoevenagel condensations or Michael additions. Rather than utilizing N-functionalized linkers as a source of basicity, the intrinsic basicity of these materials arises from the presence of the phenolate oxygen atoms coordinated to the metal ions. The overall activity is due to a complex interplay of the basic properties of these structural phenolates and the reactant binding characteristics of the coordinatively unsaturated sites. The nature of the active site and the order of activity between the different M(2)dobdc materials were rationalized via computational efforts; the most active material, both in theory and in experiment, is the Ni-containing variant. The basicity of Ni(2)dobdc was experimentally proven by chemisorption of pyrrole and observation by IR spectroscopy. (C) 2014 Elsevier Inc. All rights reserved.
[EN] POLYMER SUPPORTED BORON CATALYST AND METHOD FOR PRODUCING MICHAEL ADDITION REACTION PRODUCT USING THAT CATALYST<br/>[FR] CATALYSEUR À BASE DE BORE SUPPORTÉ SUR UN POLYMÈRE ET PROCÉDÉ DE PRODUCTION D'UN PRODUIT DE LA RÉACTION D'ADDITION DE MICHAËL UTILISANT CE CATALYSEUR