Hydrosoluble complexes

Optimization of reaction conditions was carried out with the hydrosoluble complex [(7i-allyl)Pd(TPPTS)2]Cl prepared from [(7i-allyl)PdCl]2 and two equivalent of TPPTS per Pd [54]. As low DS are expected, 1 is used as the limiting reactant (0.3 equiv./glucose unit). When the amount of co-solvent decreases, the conversion of 1 is lower but the catalyst is still active even in pure water (DS = 0.02) (Table 12) [53]. 

Formation of hydrosoluble complexes, even if the incorporated molecule is liposoluble. 

Oligosaccharide-salicylaldehyde conjugates 5-8 (Table 15.1) are ready for one-step metal-salophen hydrosoluble complex formation by metal-templated reductive amination with 1,2-diaminobenzene. 

The amino acid composition of sunflower meal is generally balanced. The energy content of sunflower meal compares favorably with other oilseed meals. The energy value of a sunflower meal increases with increasing residual oil content and a reduction of the fiber content. Sunflower meal is also valuable as a calcium and phosphorous source and a good source of hydrosoluble B complex vitamins. 

Of particular importance for industry is the hydroformylation of alk-l-enes and one of the best processes developed so far for C2-C5 olefins employs a biphasic system in combination with a hydrosoluble rhodium complex bearing TPPTS as ligand [69-71], From this statement, Wasserscheid et al. investigated in the early 2000s the possibility of using ILs supported catalysts for this reaction [71-75], owing to the discovery by Chauvin that good linear/branched selectivities could be achieved... 

Considering the hydrophilic properties of the support, the effectiveness of polysaccharide aerogel microspheres as catalyst support was evidenced in the so-called Supported Aqueous Phase Catalysis [131]. The stability of the catalyst obtained was investigated in terms of textural stability and catalytic activity in the reaction of substitution of an allyl carbonate with morpholine catalyzed by the hydrosoluble Pd (TPPTS)3 complex [132]. 

With its high surface area and the accessibility to the amino groups, chitosan aerogel appeared as a good candidate to play the double role of support for metal complexes and organic base. Silica supported metallophthalocyanine are efficient catalysts for the oxidation of aromatic compounds [139]. The immobilization of hydrosoluble metallophthalocyanines (MPcS with M = Fe or Co) on chitosan aerogels afforded new heterogeneous catalysts for the aerobic oxidation of p-isophorone [140]. 

Several methods have been used for preparing the SAP catalysts. According to the preparation procedure, the methods can be classified into two groups (a) indirect methods, when the support is first impregnated with the hydrosoluble catalytic complex, then dried and rehydrated before use [6,14,15,17, 41, 42, 49] (b) direct methods, when the support, catalytic complex, and water are mixed at the same time in the reaction system [15, 21, 29]. In general, the best conversions in the hydroformylation of alkenes by SAPC have been obtained by indirect preparation. However, the direct methods being of much easier implementation than the indirect ones, they are most widely used. 

Finally, the third generation, in which a liquid-liquid biphasic system is used, corresponds to the development of the Ruhrchemie/Rhone-Poulenc process. Olefins of the organic phase are converted by a rhodium complex maintained in an aqueous phase by adjunction of an hydrosoluble phosphine, the sodium salt of the meta-sulfonated triphenylphosphine [Na][TPPTS). The separation of aldehydes from the catalytic phase is then performed by a simple decantation. 

Moreover, the reactivation of a cobalt-terminated polymer in the presence of second monomer leads to block copolymerization. In this respect, CMRP has aheady contributed to the preparation of the valuable copolymers listed in Table 4.1. For example, well-defined poly(acrylate) block copolymers were prepared via a sequential polymerization of acrylic monomers with cobalt porphyrin la or cobaloximes 2 [14, 20]. The synthesis of well-defined poly (acrylate)-b-poly(VAc) block copolymers was also achieved with complex la [26]. Co(acac)2 (3a see Figure 4.1) is the most prolific complex for the preparation of block copolymers, until now. Indeed, the sequential CMRP of VAc with NVP [33], AN [48], or vinyl pivalate (VPi) [49] leads to the corresponding block copolymers, in controlled fashion. Throughout the polymerization, the experimental conditions were necessarily adjusted, taking into consideration the reactivity of the second monomer. As an illustration of this, well-defined PVAc-b-poly(acrylonitrile) (PAN) copolymers could only be prepared via a bulk polymerization of VAc at 30 °C, followed by the AN polymerization at 0°C in solution in DMF [48]. In this case, the DMF not only serves as the solvent but also binds the metal and adjusts its reactivity. As a rule, the PVAc sequences of these copolymers were hydrolyzed in order to provide poly(vinyl alcohol) (PVA)-containing derivatives, such as hydrosoluble PVA-b-poly... 

Most of the carriers of the photosynthetic electron transfer chain are included in large transmembrane protein complexes, two in the case of bacterial photosynthesis and three for oxygenic photosynthesis. On a time-scale of several seconds, these complexes can be considered as immobilized in the membrane. Two types of soluble electron carriers establish a link between the membrane complexes ubiquinone or plastoquinone diffuse in the lipid phase of the membrane, while cyt c2 or plastocyanin which are hydrosoluble, diffuse in the periplasmic space or the internal aquous phase of the thylakoid. In a classical view of the photosynthetic apparatus, the soluble carriers are supposed to diffuse rapidly over long distances therefore, we can expect that in the dark or under weak illumination, the carriers of the electron transfer chain are close to thermodynamic equilibrium. In such circumstances, the localization of the different electron carriers within the membrane should be of little functional importance. 

Charbonnel, M.-C., C. Berthon, L. Berfhon, N. Boubals, F. Burdet, T. Duschesnem, P. Guilbaud, N. Mabille, D. Petit, and N.Zorz. 2012. Complexation of Ln(III) and Am(III) with the hydrosoluble TEDGA Speciation and thermod5mamics studies. Procedia Chemistry 7 20-26. 

Figure 4.27 Preparation of (a) hydrosoluble Imidazollnlum-chelated palladium catalyst and (b) mixed NHC-phosphine palladium complexes.

An attractive approach for the telomerization of butadiene with methanol using hydrosoluble NHC-Pd complexes was reported by Pinel and coworkers [83], In their work, they described the preparation and the use of diiFerent hydrosoluble (NHC)-Pd-based complexes a hydrosoluble imidazolinium-che-lated palladium complex and (NHC)-Pd complexes bearing one hydrosoluble phosphine ligand and one classical carbene ligand (Figure 4.27). In the presence of water, hydrosoluble (NHC)-Pd complexes were not efficient for telomerization reaction, while the latter exhibited very high activities. 

In contrast to boron-based scorpionates, such as (pyrazolyOborate and derivatives, those based on carbon, namely tm(pyrazolyl)methane, HC(pz)3, and hydrosoluble-derived ones (Scheme 2.2a), are still underexplored, in spite of then-potential, when suitably functionalized, to form water-soluble complexes. A good example is the sulfonate derivative, that is, tm(pyrazolyl)methane sulfonate (Tpms), which is hydrolytically stable over a wide pH range and leads to sandwich... 

From the environmental and economical viewpoints, water is the ideal green solvent for both the synthesis of coordination compounds and the catalytic transformations of organic molecules including the oxidative functionalization of alkanes [23]. However, the performance of catalytic reactions in aqueous medium typically requires the use of hydrosoluble catalysts that often mimic the functions of enzymes. Although various bioinspired multicopper complexes were synthesized as models of pMMO and related copper-based enzymes [3-5a], those catalysts were often not soluble in water, exhibited modest activities, or were almost not tested in oxidative transformations wherein alkanes are used as substrates. 

We have recently reported that the air-stable and hydrosoluble iminophosphorane copper(I) complex 6 is also active in CuAAC of 1-iodoalkynes in aqueous media, under mild and aerobic conditions according to click laws and displaying a broad substrate scope and functional compatibility [29] (see Scheme 15.8). It is important to note the following catalytic features (i) catalyst 6 was the first example of an isolated and crystallographically characterized copper(I) catalyst active for cycloaddition of 1-iodoalkynes with azides, to give 5-iodo-1,2,3-triazoles exclusively, (ii) The presence of a free thio moiety in the substrate does not deactivate the catalyst, a fact generally observed in CuAAC for functionalized substrates... 

The catalytic systems based on the hydrosoluble tetracopper(II) triethanolaminate complex... 

Similar yields, under the same conditions, were obtained for the water-soluble Fe(II) complexes 19-21 bearing the C-functionalized tris(pyrazolyl)methane HOCH2C(pz)3 (Table 22.1, [5e]). The hydroxo group of the scorpionate ligand imparts hydrosolubility that allows them to operate also in pure aqueous media (without any organic solvent, although less effectively). 

In recent time the number of water-soluble cryptophanes reported in the literature has increased substantially. The main reason for this arises from the rapid development of the xenon-cryptophane complexes aimed at designing biosensors for MRI applications. Nevertheless, it seems important to distinguish between two types of water-soluble cryptophanes. The first series of water-soluble cryptophanes are made from a cryptophane skeleton, which has been properly modified in order to significantly enhance its solubility in water. For instance, the hexa-carboxylate cryptophane 1 (Fig. 21.2), whose synthesis is reported below (Scheme 21.1), is sparingly soluble in neutral water and very soluble in basic solution (Na0H/H20). The second class of water-soluble cryptophanes is made of lipophilic cryptophane cores, which have been adequately functionalized in order to make the whole molecule soluble in water. For example, cryptophanol-A 2, when suitably substituted by hydrosoluble moiety at the phenol function, belongs to this second class of molecule (Fig. 21.2). Original cryptophane biosensors have been prepared by this way and will be described in more detail below. 

Hydrosoluble iridium alkyl complexes may also be prepared by hydrolysis of alkynes and alkenes promoted by water-soluble precursors. The reaction with alkynes follows the well-known mechanism demonstrated by Bianchini et al. for ruthenium complexes.A reasonable mechanism, related to that of hydrolytic breakage, has been proposed by Chin etal. to account for the hydrolysis of ethene promoted by [Cp"lr(TPPMS)Cl2] 344 in the presence of silver salts in water. Scheme 37 describes the Chin s hydrolysis of alkynes, leading to [Cp Ir(TPPMS)(CO)(CH2R)] (69 R=Ph, Bz, Bu, />-Tol) via the aquo complex [Cp Ir(TPPMS)(OH2)OTf 345... 

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