Efficient synthetic methods required to assemble complex molecular arrays include reactions that are both selective (chemo-, regio-, diastereo-, and enantio-) and economical in atom count (maximum number of atoms of reactants appearing in the products). Methods that involve simply combining two or more building blocks with any other reactant needed only catalytically constitute the highest degree of atom economy. Transition metal-catalyzed methods that are both selective and economical for formation of cyclic structures, of great interest for biological purposes, represent an important starting point for this long-term goal. The limited availability of raw materials, combined with environmental concerns, require the highlighting of these goals.

http://science.sciencemag.org/content/sci/254/5037/1471.full.pdf

The atom economy--a search for synthetic efficiency

Catalytic dehydrogenative cross-coupling: forming carbon-carbon bonds by oxidizing two carbon-hydrogen bonds

4.3. Reaction Mechanism 2373 4.4. Asymmetric Synthesis 2374 4.5. Outlook 2374 5. Alternating Polymerization of Oxiranes and CO2 2374 5.1. Reaction Outlines 2374 5.2. Catalyst 2376 5.3. Asymmetric Polymerization 2377 5.4. Immobilized Catalysts 2377 6. Synthesis of Urea and Urethane Derivatives 2378 7. Synthesis of Carboxylic Acid 2379 8. Synthesis of Esters and Lactones 2380 9. Synthesis of Isocyanates 2382 10. Hydrogenation and Hydroformylation, and Alcohol Homologation 2382

Transformation of carbon dioxide.

The chemistry of heterocyclic carbenes has experienced a rapid development over the last years. In addition to the imidazolin-2-ylidenes, a large number of cyclic diaminocarbenes with different ring sizes have been described. Aside from diaminocarbenes, P-heterocyclic carbenes, and derivatives with only one, or even no heteroatom within the carbene ring are known. New methods for the synthesis of complexes with N-heterocyclic carbene ligands such as the oxidative addition or the metal atom template controlled cyclization of β-functionalized isocyanides have been developed recently. This review summarizes the new developments regarding the synthesis of N-heterocyclic carbenes and their metal complexes.

Heterocyclic Carbenes: Synthesis and Coordination Chemistry

Organic–inorganic hybrid materials do not represent only a creative alternative to design new materials and compounds for academic research, but their improved or unusual features allow the development of innovative industrial applications. Nowadays, most of the hybrid materials that have already entered the market are synthesised and processed by using conventional soft chemistry based routes developed in the eighties. These processes are based on: a) the copolymerisation of functional organosilanes, macromonomers, and metal alkoxides, b) the encapsulation of organic components within sol–gel derived silica or metallic oxides, c) the organic functionalisation of nanofillers, nanoclays or other compounds with lamellar structures, etc. The chemical strategies (self-assembly, nanobuilding block approaches, hybrid MOF (Metal Organic Frameworks), integrative synthesis, coupled processes, bio-inspired strategies, etc.) offered nowadays by academic research allow, through an intelligent tuned coding, the development of a new vectorial chemistry, able to direct the assembling of a large variety of structurally well defined nano-objects into complex hybrid architectures hierarchically organised in terms of structure and functions. Looking to the future, there is no doubt that these new generations of hybrid materials, born from the very fruitful activities in this research field, will open a land of promising applications in many areas: optics, electronics, ionics, mechanics, energy, environment, biology, medicine for example as membranes and separation devices, functional smart coatings, fuel and solar cells, catalysts, sensors, etc.

Applications of hybrid organic–inorganic nanocomposites

Un hydrogel a base de polyoxazoline est prepare par reaction de Diels-Alder entre un poly(N-acetylethylenimine) (PAEI) modifie par le furane et un PAEI modifie par le maleimide. Le comportement du gonflement de l'hydrogel est etudie en fonction de la teneur en groupements fonctionnels dans le prepolymere. L'interconversion reversible entre l'hydrogel et le polymere lineaire soluble est realisee par un changement de temperature

Reversible gelation of polyoxazoline by means of diels-alder reaction

This article describes organic polymer hybrids with silica gels formed by means of the sol-gel method The incorporation of organic polymers at the level of molecular dispersion into a metal oxide matrix was accomplished by the hydrolysis-condensation of tetraalkoxysilane (orthosilicate ester) in the presence of the appropriate organic polymer

Organic polymer hybrids with silica gel formed by means of the sol-gel method

Chelating properties of linear and branched poly(ethylenimines)

Facile generation of a reactive palladium(II) enolate intermediate by the decarboxylation of palladium(II) .beta.-ketocarboxylate and its utilization in allylic acylation

Takeo Saegusa

Papers

Reversible gelation of polyoxazoline by means of diels-alder reaction

Organic polymer hybrids with silica gel formed by means of the sol-gel method

Chelating properties of linear and branched poly(ethylenimines)

Facile generation of a reactive palladium(II) enolate intermediate by the decarboxylation of palladium(II) .beta.-ketocarboxylate and its utilization in allylic acylation

Synthesis of 1,4-diketones by oxidative coupling of ketone enolates with copper(II) chloride