Encapsulation of chiral Fe(salen) in mesoporous silica structures for use as catalysts to produce optically active sulfoxides

Abstract

Solid catalysts which are heterogeneous at the macroscopic scale but homogeneous at the microscopic level were prepared by the encapsulation of Fe(salen) by a “ship in a bottle” approach.

An Overview of the Challenges and Progress of Synthesis, Characterization and Applications of Plugged SBA-15 Materials for Heterogeneous Catalysis

“…The plugged SBA-15 materials were also used for confinement of various metal complexes by the ship-in-the-bottle synthesis. The systematic study of the confinement of metal complexes of M-salen (M = Co and Fe) by the ship-in-the-bottle synthesis on various plugged SBA-15 with different window sizes in comparison with the other mesoporous materials was intensively investigated for various reactions [12,60]. The conventional SBA-15 did not retain any metal complexes, due to washing out during the ship-in-the-bottle preparation.…”

CO2-Switchable Single-Chain Polymeric Nanoparticles Enable Gas-Controllable Reaction Separation for Asymmetric Catalysis in Water

“…ICP-OES analysis gave convincing evidence for the perfect stability of PD x (IS) y , since the iron content in recovered catalysts (0.107, 0.059, and 0.041 mmol•g −1 for recovered PD 155 (IS) 6 , PD 202 (IS) 4, and PD 218 (IS) 3 , respectively) is almost identical to that in the corresponding fresh one. Obviously, leaching of iron species, the main reason for deactivation of iron complex-based catalysts, 51 did not occur during the addition. Negligible leaching loss of iron species (less than 1.0 ppm iron species) was detected in the reaction solution.…”

FDU-12-C encapsulatedt-Bu(R,R)CoII(salen) as a cathode catalyst for asymmetric electrocarboxylation of 1-phenylethyl chloride with CO2

“…Notably, chiral catalysts can be immobilized on the electrodes by covalent grafting 26,27 or encapsulation. 28 As the chiral structure of the catalyst might be distorted after chemical modification, the enantioselectivity tends to deteriorate after covalent grafting. 29 On the other hand, encapsulation can realize the immobilization of the catalysts without chemical modification, however, the decrease of activity caused by the leaching of the catalysts from the solid surfaces and the difficulty of reactants approaching the active sites is still a huge challenge for immobilization of chiral catalysts.…”