A Mixed Heterobimetallic Y/Eu-MOF for the Cyanosilylation and Hydroboration of Carbonyls

Abstract

Herein, to the best of our knowledge, the first heterobimetallic Y/Eu porous metal–organic framework (MOF), based on 3-amino-4-hydroxybenzoic acid (H2L) ligand, with the following formulae {[Y3.5Eu1.5L6(OH)3(H2O)3]·12DMF}n (in advance, namely Y/Eu-MOF), is described. The three-dimensional structure has been synthesized by solvothermal routes and thoroughly characterized, by means of single crystal X-ray diffraction, powder X-ray diffraction, electronic microscopy, ICP-AES, electrophoretic mobility, and FTIR spectra. Intriguingly, the porous nature allows for coordinated solvent molecules displacement, yielding unsaturated metal centers, which can act as a Lewis acid catalyst. This novel supramolecular entity has been tested in cyanosilylation and hydroboration reactions on carbonyl substrates of a diverse nature, exhibiting an extraordinary activity.

Metal‐Organic Frameworks for Catalytic Construction of C−B Bond and Related Reactions

“…Inductively coupled plasma optical emission spectroscopy (ICP-OES) showed Zr/Fe ratios of 1.66 and 1.44, corresponding to the Fe-loadings of 60 % and 71 % with respect to the valinol Recently, heterobimetallic Y/Eu porous MOF, based on 3amino-4-hydroxybenzoic acid linker was reported. [50] The solvo- Lanthanide based Y/EuÀ MOF was employed as the catalyst (0.5 mol %) in the cyanosilylation of aromatic, heteroaromatic, and aliphatic aldehydes and ketones with TMSCN as the nucleophile under neat condition at room temperature giving the desired addition products in good to excellent yields. Also, Y/EuÀ MOF (0.5 mol %) catalyzed hydroboration of wide range of ketones with HBpin at room temperature under solvent-free condition.…”

“…Recently, heterobimetallic Y/Eu porous MOF, based on 3‐amino‐4‐hydroxybenzoic acid linker was reported [50] . The solvothermal interaction of 3‐amino‐4‐hydroxybenzoic acid ligand with Y−Eu metal gave three‐dimensional porous Y/Eu−MOF.…”

Synthesis, Characterization, and Catalytic Performance of a New Heterobimetallic Y/Tb Metal–Organic Framework with High Catalytic Activity

“…35 Both systems afford the corresponding alcohols with TOF values from 20 to 21 h −1 and 3 and 7 cycles of recyclability, respectively (Table S14). The activity of the heterobimetallic Y/Eu-MOF, 35 which shares the same ligand as the Tb and Y/Tb-MOFs described herein, will also be compared. carbonylic substrates.…”

“…carbonylic substrates. These novel systems represent an extension of our work on isostructural metal−organic frameworks based on Y, 34 Eu, 21 Y/Eu, 35 and Dy, 44 with the target of exploring how partial substitution by a second metal will enable the bimetallic system to exhibit synergistic catalytic effects.…”

“…The catalytic activity of our new heterobimetallic Y/Tb-MOF (0.5 mol %) and monometallic Tb-MOF (0.5 mol %) was first evaluated in the cyanosilylation of different ketones (1) using TMSCN as a nucleophile, solvent-free reaction conditions, and room temperature under a N 2 atmosphere. These conditions were used previously for the reported monometallic Y-or Eu-MOF, 19,21 bimetallic Y/ Eu-MOF, 35 and with catalyst GR-MOF-6. 19 First, the evaluation of the blank reaction using acetophenone (1a) was carried out, obtaining no product 2a after a reaction time of 24 h, whereas in the presence of the catalysts, quantitative conversions were achieved (entry 1, Table 1) after 24 h. To evaluate the scope of the reaction, ketones with different chemical natures such as aromatic with electrondonating groups (1b) and electron-withdrawing groups (1c), heteroaromatic (1d), and also bearing aliphatic substituents (1e) were tested (entries 2−5).…”