Solid organic reactions

As was stated above, the very strong acidity (and probably together with the organophilicity of the pore wall) makes these salts very active catalysts in liquid-solid organic reaction systems. We wish to emphasize that this is the first example for the shape selective catalysis of heteropolyacids at least to our knowledge. 

Toda, F. Solid-to-solid organic reactions. React. Mol. Cryst. 1993,177-201. 

Solid State and Related Reactions. The area of solid/solid organic reactions has been explored. " Results on the solid state nuclear bromination of aromatic compounds with NBS as well as some theoretical insights into the mechanism of the reaction have been reported. NBS on a solid support has been used to sythesize benzylic bromides under neutral conditions and for the functionalization of a-oxoaldehyde-supported silicas. ... 

Rothenberg G, Downie AP et al (2001) Understanding solid/solid organic reactions. J Am Chem Soc 123 8701 708... 

Solid organic compounds when isolated from organic reactions are seldom pure they are usually contaminated with small amounts of other compounds ( impurities ) which are produced along with the desired product. Tlie purification of impure crystalline compounds is usually effected by crystallisation from a suitable solvent or mixture of solvents. Attention must, however, be drawn to the fact that direct crystallisation of a crude reaction product is not always advisable as certain impurities may retard the rate of crystallisation and, in some cases, may even prevent the formation of crystals entirely furthermore, considerable loss of... 

Quantitative studies of solid-state organic reactions were performed by Glazman (267. 268). Equal amounts of acetic anhydride and 2-aminothiazole (grain diameter 0.15 mm) were mixed for 20 rain, and the mixture was heated in a glycerol bath at 0.5°C per minute. Heating curves showed that the reaction starts in the solid phase the use of an eutectic composition of organic reactants increases the yields. 

Y. Bing, Monitoring the Progress and the Yield of Solid Phase Organic Reactions Directly On Resin Supports, Acc Chem Res 31 621-630 1998. 

When the polymer was prepared by the suspension polymerization technique, the product was crosslinked beads of unusually uniform size (see Fig. 16 for SEM picture of the beads) with hydrophobic surface characteristics. This shows that cardanyl acrylate/methacry-late can be used as comonomers-cum-cross-linking agents in vinyl polymerizations. This further gives rise to more opportunities to prepare polymer supports for synthesis particularly for experiments in solid-state peptide synthesis. Polymer supports based on activated acrylates have recently been reported to be useful in supported organic reactions, metal ion separation, etc. [198,199]. Copolymers are expected to give better performance and, hence, coplymers of CA and CM A with methyl methacrylate (MMA), styrene (St), and acrylonitrile (AN) were prepared and characterized [196,197]. 

Hydrogen bonds can exist in the solid and liquid phases and in solution. Many organic reactions that will be discussed in later chapters can be done in aqueous... 

Organic Solid State Reactions Volume Editor Toda, F. 

This work was initiated for the purpose of evaluating the feasibility of synthesizing hexyl acetate (ROAc) fi-om n-hexyl bromide (RBr) and sodium acetate (NaOAc) by a novel PTC technique. In this new technique, the solid-liquid reaction was catalyzed by a catalyst-rich liquid phase in a batch reactor. Because there a solid phase and two liquid phases coexist, it is called as a SLL-PTC system [3]. Actually, this liquid phase is the third liquid phase in the tri-liquid PTC system. It might be formed when the phase-transfer catalyst is insoluble or slightly soluble in both aqueous and organic phases. Both aqueous and organic reactants can easily transfer to this phase where the intrinsic reaction occurs [4, 5]. 

Organosilanes, especially dimethyldichlorosilane (M2), are important chemicals used in the silicone industries. The direct reaction of silicon with an organic halide to produce the corresponding organosilanes as a gas-solid-solid catalytic reaction was first disclosed by Rochow [1]. In the reaction, a copper-containing precursor first reacts with silicon particles to form the catalytically active component, which is a copper-silicon alloy, the exact state of which is still under discussion. As the reaction proceeds. Si in the alloy is consumed, which is followed by the release of copper. This copper diffuses into the Si lattice to form new reaction centers until deactivation occurs. The main reaction of the direct process is ... 

Toda F (ed) (2000) Organic Solid-State Reactions. Kluwer, Dordrecht Toda F, Bishop R (eds) (2004) Separations and Reactions in Organic Supramolecular Chemistry. WUey, New York... 

Shape selective catalysis as typically demonstrated by zeolites is of great interest from scientific as well as industrial viewpoint [17], However, the application of zeolites to organic reactions in a liquid-solid system is very limited, because of insufficient acid strength and slow diffusion of reactant molecules in small pores. We reported preliminarily that the microporous Cs salts of H3PW12O40 exhibit shape selectivity in a liquid-solid system [18]. Here we studied in more detail the acidity, micropore structure and catal3rtic activity of the Cs salts and wish to report that the acidic Cs salts exhibit efficient shape selective catalysis toward decomposition of esters, dehydration of alcohol, and alkylation of aromatic compound in liquid-solid system. The results were discussed in relation to the shape selective adsorption and the acidic properties. 

Most of the known organic reaction yield sooner or later precipitates or involves directly the addition of solid reagents [78]. Hence fouling phenomena are rather... 

Examples of commercially applied solid base catalysts are much fewer than for solid acids. Nevertheless, much attention is currently focused on the development of novel solid base catalysts for classical organic reactions such as aldol condensations, Michael additions, and Knoevenagel condensations, to name but a few. 

Ion exchange (IX) is a very useful technique for the concentration, the purification and the separation of chemically similar metallic elements present in an aqueous solution. In its most popular form of application, the metal-bearing aqueous solution is passed through a bed of solid organic resin in a particulate form wherein the sorption of the metal ions on the resin takes place by ion-exchange reactions. The pregnant resin is washed free of the entrapped feed solution and then brought into contact with an eluant of suitable composition and volume so that the resin releases the metal ions back to the eluant. The ratio of the volume of the feed and that of the eluant determines the extent of concentration that can be achieved. Purification and separation are achievable if the resin is selective or specific with respect to the metal ions of interest in comparison to impurity ions. 

Kaupp G (2005) Organic Solid-State Reactions with 100% Yield. 254 95-183 Kawasaki T, see Okahata Y (2005) 260 57-75 KawashimaT, see Kano N (2005) 251 141-180... 

Komatsu K (2005) The Mechanochemical Solid-State Reaction of Fullerenes. 254 185-206 Kremsner JM, Stadler A, Kappe CO (2006) The Scale-Up of Microwave-Assisted Organic Synthesis. 266 233-278... 

We do hope that the new findings about solid-solid reactions become a starting point for reconsidering and carefully reinvestigating organic reactions which have long been studied in solvents and the belief that most reactions only occur in solution. 

It is envisioned that this new LAB technology would be most readily applicable industrially as a retrofit to existing LAB commercial units, possibly as a slip-stream reactor.19,20 The manufacturer would then have the flexibility to tailor the 2-phenyl content of their LAB and LAS products according to the customer s specific needs. Alternative solid acid reactor configurations have been presented at an earlier Organic Reactions Catalysis Meeting.21... 

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