A Janus‐type Heterogeneous Surfactant for Adipic Acid Synthesis

Abstract

A highly water‐dispersible heterogeneous Brønsted acid surfactant was prepared by synthesis of a bi‐functional anisotropic Janus‐type material. The catalyst comprises ionic functionalities on one side and propyl‐SO3H groups on the other. The novel material was investigated as a green substitute of a homogeneous acidic phase transfer catalyst (PTC). The activity of the catalyst was investigated for the aqueous‐phase oxidation of cyclohexene to adipic acid with 30 % hydrogen peroxide even in a decagram‐scale. It can also be used for the synthesis of some other carboxylic acid derivatives as well as diethyl phthalate.

Fast and Selective Aqueous-Phase Oxidation of Styrene to Acetophenone Using a Mesoporous Janus-Type Palladium Catalyst

“…After crushing, nanosheets of catalyst 2 were formed (Figure 1b). To find evidence for a selective surface functionalization of catalyst 2, the material in the middle of crushing process was labelled with negatively charged citrate-capped Fe 3 O 4 nanoparticles (Fe 3 O 4 @citrate) according to our previously described procedure [30]. The loading of palladium in the catalyst was determined based on an atomic absorption spectroscopy (AAS) to be 0.22 mmol•g -1 .…”

“…After crushing, nanosheets of catalyst 2 were formed (Figure 1b). To find evidence for a selective surface functionalization of catalyst 2, the material in the middle of crushing process was labelled with negatively charged citrate-capped Fe3O4 nanoparticles (Fe3O4@citrate) according to our previously described procedure [30]. After labelling the catalyst by mixing it with citrate@Fe3O4, the outer surface of the material that contains the nitrogen ligand can interact with the labelling agent (Figure 1c), while due to lack of noticeable functionality of the inner surface (i.e., relatively inert octyl groups), it remained almost remains untouched (Figure 1d).…”

“…To this aim, we introduced simple and practical techniques for the synthesis of heterogeneous Janus-type interphase catalysts by a modification of the Stöber process [29][30][31]. The catalysts showed high activity for the synthesis of a series of fine chemicals.…”

Dinuclear Copper Complex Immobilized on a Janus-Type Material as an Interfacial Heterogeneous Catalyst for Green Synthesis

“…n -Decane induces the formation of a hollow architecture and a particle size growth of up to 1 μm. To provide evidence for the selective surface bifunctionalization, catalyst 6 was treated with negatively charged, citrate-capped Fe 3 O 4 nanoparticles (citrate@Fe 3 O 4 ) according to the procedure of our recently published article …”

“…It was shown that organic reactions can proceed efficiently inside temporarily formed microreactors. Besides, the Janus strategy was employed for the synthesis of a highly water-dispersible heterogeneous surfactant, allowing the aqueous-phase synthesis of industrially important dicarboxylic acids such as adipic acid and glutaric acid …”