Subject(s)
Metals/chemistry , Palladium/chemistry , Catalysis , Crystallography, X-Ray , Hydrogen Bonding , Molecular StructureABSTRACT
A bifunctional imidazolium linker was used for the production of highly crosslinked element organic frameworks by Suzuki-coupling with tetrafunctional boronic acids. The resulting porous materials are good heterogeneous organocatalysts in the N-heterocyclic carbene-catalyzed conjugated umpolung of α,ß-unsaturated cinnamaldehyde.
Subject(s)
Acrolein/analogs & derivatives , Boronic Acids/chemistry , Heterocyclic Compounds/chemistry , Imidazoles/chemical synthesis , Methane/analogs & derivatives , Acrolein/chemistry , Catalysis , Heterocyclic Compounds/chemical synthesis , Imidazoles/chemistry , Methane/chemistry , Molecular Structure , Particle Size , Porosity , Stereoisomerism , Surface PropertiesABSTRACT
Chiral metal-organic frameworks with a three-dimensional network structure and wide-open pores (>30 Å) were obtained by using chiral trifunctional linkers and multinuclear zinc clusters. The linkers, H(3) ChirBTB-n, consist of a 4,4',4''-benzene-1,3,5-triyltribenzoate (BTB) backbone decorated with chiral oxazolidinone substituents. The size and polarity of these substituents determines the network topology formed under solvothermal synthesis conditions. The resulting chiral MOFs adsorb even large molecules from solution. Moreover, they are highly active Lewis acid catalysts in the Mukaiyama aldol reaction. Due to their chiral functionalization, they show significant levels of enantioselectivity, thereby proving the validity of the modular design concept employed.
