Michel Wong Chi Man

Biodegradable Ethylene‐Bis(Propyl)Disulfide‐Based Periodic Mesoporous Organosilica Nanorods and Nanospheres for Efficient In‐Vitro Drug Delivery

Periodic mesoporous organosilica nanorods and nanospheres are synthesized from 1,4-bis(triethoxysilyl)ethylene and bis(3-ethoxysilylpropyl)disulfide. The nanosystems present the long-range order of the hexagonal nanostructure. They are degraded in simulated physiological conditions. The loading and release of doxorubicin with these nanosystems are both pH dependent. These nanoparticles are endocytosed by breast cancer cells and are very efficient for doxorubicin delivery in these cells.

Hybrid materials: versatile matrices for supporting homogeneous catalysts

Hybrid materials are increasingly used for supporting homogeneous catalysts. This review describes the various methodologies used to synthesize such hybrid materials or to graft catalysts on inorganic or hybrid supports. Applications of these materials for reactions mediated by supported organometallic or organic catalysts are presented.

THE DESIGN OF SELECTIVE CATALYSTS FROM HYBRID SILICA-BASED MATERIALS

Abstract The sol–gel processing of appropriated molecular precursors easily leads to a variety of mixed materials. Silica-based organic–inorganic hybrids constitute a very versatile class of solids. Their preparation in a controlled way can lead to materials with intrinsic properties. This paper will concentrate on the potential uses of hybrids for the preparation of catalytic materials by design. It offers unique possibilities (i) to obtain dispersed metal species or particles on oxide supports; (ii) to control the pore structure of the catalytic material; and (iii) to prepare new hybrid supports with selective properties.

Syntheses and applications of periodic mesoporous organosilica nanoparticles

Periodic Mesoporous Organosilica (PMO) nanomaterials are envisioned to be one of the most prolific subjects of research in the next decade. Similar to mesoporous silica nanoparticles (MSN), PMO nanoparticles (NPs) prepared from organo-bridged alkoxysilanes have tunable mesopores that could be utilized for many applications such as gas and molecule adsorption, catalysis, drug and gene delivery, electronics, and sensing; but unlike MSN, the diversity in chemical nature of the pore walls of such nanomaterials is theoretically unlimited. Thus, we expect that PMO NPs will attract considerable interest over the next decade. In this review, we will present a comprehensive overview of the synthetic strategies for the preparation of nanoscaled PMO materials, and then describe their applications in catalysis and nanomedicine. The remarkable assets of the PMO structure are also detailed, and insights are provided for the preparation of more complex PMO nanoplatforms.

Chiral organic–inorganic solids as enantioselective catalytic materials

New enantioselective catalytic materials result from the sol–gel hydrolysis condensation of silyl-substituted chiral diamine–rhodium complexes.

Nanostructuring organo-silicas: combination of intermolecular interactions and molecular recognition properties to generate self-assembled hybrids with phenylene or adenine⋯thymine bridging units

Owing to hydrophobic interactions, silyl linkers containing long alkylene chains allowed the synthesis of self-organised hybrids. Lamellar organo-silicas with phenylene or a hydrogen-bonded adenine⋯thymine complex as the bridging units are reported.

Sol–gel immobilized and reusable copper-catalyst for arylation of phenols from aryl bromides

A simple β-diamide ligand was immobilized by the sol–gel process on hybrid silica for Cu-mediated O-arylation reactions. Combined with 5% of CuI, the latter can easily be recovered and reused to generate diarylethers under smooth conditions from cheap aryl bromides in an eco-friendly solvent (MIBK). Besides, negligible metal leaching occurred after reaction in solution from the supported catalyst.

Imidazolium-derived organosilicas for catalytic applications

Imidazolium salts are applied in different fields of research and have found a wide variety of applications owing to their distinctive properties. This review exclusively focuses on the various methods (grafting, surfactant-assisted sol–gel synthesis, bridged silsesquioxanes formation) described in recent years for the covalent immobilization of imidazolium salts on silica supports via C–Si bonds and on the catalytic applications of the resulting silica-supported imidazolium salts and NHC complexes. C–C bond formation reactions such as cross-coupling, olefin metathesis or organocatalyzed Knoevenagel condensations as well as functionalization reactions are described. This review is intended to help in inspiring future developments and interest in the growing field of catalysis by supported imidazolium salts and NHC complexes based on organosilicas.

Mesoporous-Silica-Functionalized Nanoparticles for Drug Delivery.

The ever-growing interest for finding efficient and reliable methods for treatment of diseases has set a precedent for the design and synthesis of new functional hybrid materials, namely porous nanoparticles, for controlled drug delivery. Mesoporous silica nanoparticles (MSNPs) represent one of the most promising nanocarriers for drug delivery as they possess interesting chemical and physical properties, thermal and mechanical stabilities, and are biocompatibile. In particular, their easily functionalizable surface allows a large number of property modifications further improving their efficiency in this field. This Concept article deals with the advances on the novel methods of functionalizing MSNPs, inside or outside the pores, as well as within the walls, to produce efficient and smart drug carriers for therapy.

Click approaches to functional water-sensitive organotriethoxysilanes.

The derivatization of functional organic fragments with triethoxysilyl groups to afford hydrolyzable organosilanes with targeted properties using the copper-catalyzed alkyne azide cycloaddition reaction under strictly anhydrous conditions is described according to two approaches, starting from five silylated substrates. This high yield, fast, and selective method is applicable to a wide range of substrates and is expected to lead to important achievements in the field of functional hybrid silica.