Two cyclotriveratrylene metal–organic frameworks as effective catalysts for Knoevenagel condensation and CO₂ cycloaddition with epoxides

Abstract

In this work, we report two MOFs assembled with a novel imidazole-functionalized cyclotriveratrylene ligand, where 1 and 2 could be used as efficient catalysts for Knoevenagel condensation and CO2 cycloaddition with epoxides, respectively.

Coordination polymers with embedded recognition sites: lessons from cyclotriveratrylene-type ligands

“…where BDC is benzene-1,3dicarboxylate. 26 [Cd 3 (L15)(BDC) 3 ] forms an intricate 3D coordination polymer that contains the BDC-expanded capsule-motifs shown in Fig. 11c.…”

“…Thus far, reports of applications of these materials are limited. Guest exchange or guest uptake has been established in some cases, and includes inclusion of small solvent molecules, 26 iodine, 21 and larger fullerene guests. 20 with complete exchange of solvent to an isomorphic structure.…”

“…Pillararenes, crown ethers, cucurbiturils and cyclodextrins have also been employed. Our own work, [9][10][11][12][13][14][15][16][17][18][19][20][21] alongside that of other research groups, [22][23][24][25][26] has investigated the use of functionalised cyclotriveratrylenes (CTVs) as bridging ligands for coordination polymers. Cyclotriveratrylene (CTV) is a bowl-shaped molecular host with a tribenzo [a,d,g] cyclononatriene core.…”

“…(a) [Ag 3 (NMP) 6 (L17) 2 ]•3(ClO 4 )•n(NMP): [Ag(L17) 2 ] + framework showing cage-like pore bounded by two head-to-head L16-ligands (in green); inset shows full coordination sphere of connecting Ag(I) showing decoration by two [Ag(NMP)] moieties. NMP shown in green, only one L17 shown in full for clarity; 17 (b) linked hexagonal prisms within the [Cu I 4 Cu II 1.5 (L1) 3 (CN) 6] + 3D network structure, all Cu centres (green spheres) are either 3 or 4-coordinate with edge-shared along the Cu-CN-Cu chains occurring between prisms above and below those shown, carbon atoms of cyanide ligands shown in purple;20 (c) expanded capsule-like motif within the 3D coordination network of [Cd 3 (L15) (BDC) 3 ], structure is 4-fold interpenetrating 26.…”

Revisiting Hydroxyalkylation of Phenols with Cyclic Carbonates

“…To further showcase the utilities of this reaction system, we began to tackle the ethoxylation reactions of aromatic diols. We soon realized that catechol could undergo an efficient bis‐hydroxyethylation in the presence of 2.4 equivalent of EC; in addition to 1 n , a minor amount of benzo‐1,4‐dioxane (5% yield), derived from an intramolecular dehydration reaction was isolated as a side product. The condensation of catechol and 1.2 equivalent of EC was a moderately selective route giving a crude mixture of the mono‐hydroxyethylated product 1 n’ and 1 n (4.8:1 as determined by 1 H NMR analysis), from which compound 1 n’ was isolated in 55% yield (Scheme ).…”