Xavier Cattoën

Stable Noncyclic Singlet Carbenes

2.2.1. Diaminoand Aminohydrazinocarbenes 3338 2.2.2. Aminothioand Aminooxycarbenes 3340 2.3. Phosphinoaryland Phosphinoalkylcarbenes 3341 2.4. Aminoaryland Aminoalkylcarbenes 3344 2.5. Aminophosphonio and Aminosilylcarbenes 3346 2.6. Aminophosphinocarbenes 3347 3. Reactivity 3348 3.1. Typical Carbene Behavior 3348 3.1.1. Coupling Reactions 3348 3.1.2. Cycloaddition Reactions 3352 3.1.3. Insertion Reactions 3355 3.1.4. Migration Reactions 3358 3.2. Basic/Nucleophilic Behavior 3359 3.2.1. Protonation of Carbenes 3359 3.2.2. Reactions with Group 14 Electrophiles 3360 3.2.3. Reactions with Group 13 Lewis Acids 3360 3.2.4. Reactions with Group 15 Electrophiles 3361 3.3. Electrophilic Behavior 3362 3.3.1. Reaction with 1,5-Diazabicyclo[4.3.0]non-5-ene (DBN) 3362

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.

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.

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.

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.

One‐Pot Construction of Multipodal Hybrid Periodic Mesoporous Organosilica Nanoparticles with Crystal‐Like Architectures

The design of hybrid multipodal PMO (mp-PMO) nanoparticles with crystal-like architectures elaborated in a one-pot, two-step process, involving the preparation of a benzene-based spherical PMO core followed by the formation of ethylene-based rod-shaped PMO pods on these cores is described.

Recyclable silica-supported prolinamide organocatalysts for direct asymmetric Aldol reaction in water

Asymmetric organocatalytic materials based on a prolinamide scaffold have been synthesized according to different synthetic routes from a monosilylated precursor: simple or surfactant-assisted co-condensation and grafting on preformed mesostructured silica. The catalytic properties of these materials have been compared for direct asymmetric aldol reactions. The best catalytic material results from a simple co-condensation without structure-directing agent. Simple and green conditions are used for the aldol reaction, the process being performed in water at room temperature, with relatively low amounts of supported organocatalysts and in the absence of an acid co-catalyst. Good recyclabilities are observed without the need for catalyst regeneration, with enantioselectivities (ee up to 92%) higher than that of the parent homogeneous catalysts.

Enhanced Two‐Photon Fluorescence Imaging and Therapy of Cancer Cells via Gold@Bridged Silsesquioxane Nanoparticles

A two-photon photosensitizer with four triethoxysilyl groups is synthesized through the click reaction. This photosensitizer allows the design of bridged silsesquioxane (BS) nanoparticles through a sol-gel process; moreover, gold core BS shells or BS nanoparticles decorated with gold nanospheres are synthesized. An enhancement of the two-photon properties is noted with gold and the nanoparticles are efficient for two-photon imaging and two-photon photodynamic therapy of cancer cells.

Porphyrin-functionalized mesoporous organosilica nanoparticles for two-photon imaging of cancer cells and drug delivery

The synthesis of a zinc porphyrin derivative possessing eight triethoxysilyl groups was performed through a CuAAC-click reaction. This porphyrin was covalently entrapped in ethenylene-bridged mesoporous organosilica nanoparticles which efficiently allowed performing doxorubicin delivery and two-photon imaging of breast cancer cells.