Nanostructured Silica-Based Organic-Inorganic Hybrid Materials-Evidence for Self-Organization of a Xerogel Prepared by Sol-Gel Polymerization

A hydrolytic polycondensation reaction of a rigid, rodlike nonmesomorphous precursor leads to an isotropic sol and then an anisotropic birefringent xerogel (see scheme). Optical and X-ray structural analyses demonstrate a short-range order and the possibility of a crystalline order.     

1,4-addition reactions to methacrylamide : a one pot synthesis of 3,4-dihydro 2(1H)-pyridinones and 3,5-disubstituted glutarimides

Ketones and β-cyano or β-keto esters were found to add directly to methacrylamide in a one pot process in the presence of CsF/Si(OCH₃₄ to give 1,4-addition compounds.     

Uses of SiN bonds in organic synthesis. A direct synthesis of functional protected propargylic primary amines.

An easy route to lithium N,N-bis(trimethylsilyl)aminomethylacetylide 1 is described. Reactions of 1 with electrophiles give rise to various protected primary amines.     

Alkali metal hydrides: New metallating reagents for germanium and tin

New procedures for the preparation of organogermyl- and stannyl-sodium or -potassium, which undergo coupling reactions with alkyl, allyl, and benzyl halides and α-enones, are reported.     

Valorization of by-products of the sugar industry: New nanostructured hybrid materials containing sugar derived structures

This article describes some possibilities opened by sugar-derived structures in the field of new materials. We selected commercially available structures, mannitol M, sorbitol S, dulcitol D, which are low cost by-products of industrial sugars used for food. These structures present OH functions regularly distributed on a chiral carbon chain. We report here a valorization of these by-products by incorporating them into new silica hybrids. The synthesis, achieved by direct silylation of polyols M, S and D either with 3-(triethoxysilylpropyl)isocyanate, or 3-iodopropyltriethoxysilane led directly to the corresponding materials. The polycondensation occurred in situ because of the presence of a very tight hydrogen bonds network between the organic cores. Incorporation of gold (0) nanoparticles and lanthanide complexations were successfully investigated.