Self-assembly from metal–organic vesicles to globular networks: metallogel-mediated phenylation of indole with phenyl boronic acid

Abstract

Self-assembly of the conformationally flexible bismethylimidazolyl ligands with Pd(OAc)(2) is described. Depending on whether the ligands provide the hydrogen bonding donor, a switching of metal-organic vesicles to globular networks gelating solvents is achieved. The metallogels exhibit catalytic activity for the cross-coupling of indole with phenyl boronic acid.

A silver-induced metal-organic gel based on biscarboxyl-functionalised benzimidazole derivative: stimuli responsive and dye sorption

“…In spite of has also been researched (32). In very few cases, dye supramolecular organogels or hydrogels using molecules sorption (13,33) phenomena have also been studied with containing diverse functional groups, which have been the gel materials.…”

Discrete and Polymeric Self‐Assembled Palladium(II) Complexes as Supramolecular Gelators

“…[22] Relatedg elators 11 b, 11 c,a nd 12 a were prepared in as imilar manner (Figures 11 and 12). [22] TEM analysis of the compounds at lower concentrationsr evealed the formation of nanoscale particles. However,a th igherc oncentrations a3 Dglobularnetwork could be seen (Figures 11band 12b).…”

“…[10,11] Self-assembled palladium(II) complexes were thus applieda st ectons in crystal engineering to make fascinating 1D, 2D, and 3D networks in the solid state. Mono-, bi-, and trinucleard iscrete complexes with variousc ompositions (PdL 2 ,P dL, Pd 2 L, Pd 2 L 2 ,P d 2 L 4 , Pd 3 L 6 ;L= ligand or metalloligand) are reported in the literature as gelators [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] and described below.T he molecular architectures of the complexes (gelators) are well characterized;h owever,f urthers tructuralc hanges during gelation cannot be ruled out. [10,11] In addition to the hierarchyi nt he solid state, aggregation of palladium(II)-based self-assembled coordination complexes to form metallogels is also known in the literature.…”

Title Pages

“…Asymmetric hydrogenation under supramolecular catalysis has added yet another dimension in this arena, where two devices come to mind: the creation of active catalysts in situ through inter-ligand hydrogen-bonding, as represented by a new chiral rhodium(I)-phthalimidophosphite complex, Rh(I)-PhthalaPhos 15 ; and through self-assembly by heterobimetallic coordination, as in the in situ generation of a heterogeneous, readily recyclable rhodium(I) phosphoromonoamidite complex linked as a self-supported polymer via an iron(II)-terpyridyl residue 16 . Here, one might also mention metallogel-mediated catalysis within self-assembled globular networks 17 , and the prospect of switching reactions on and off, as with allosteric enzymes, by effectively opening and closing supramolecular assemblies in the presence of suitable additives 18 . Nitrogen-directed o-acoxylation is now a firmly established aspect of palladium catalysis, recently extended with a 'traceless' methodology permitting a simple removal or displacement of the directing group (2-pyridyldiisopropylsilyl) [PyDipSi] by electrophiles 19 .…”