Itaconate derivatives dimethyl

Sometimes, the compatibilization of PP/EPDM blends has been the key issue to improve the properties of the blends. Lopez-Manchado s group (7) studied the effect of grafted PP on the compatibihty and properties of PP-EPDM thermoplastic elastomer blends. They functionalized the isotactic PP (iPP) through grafting in Brabender plasticorder with two itaconate. The functionalization of iPP was performed by melt blending through grafting with two itaconic acid derivatives, monomethyl itaconate and dimethyl itaconate (MMI and DMI, respectively). 

It also has been found that chiral monodentate phosphine derivatives can be used in place of the diphosphine. Reetz et al. studied the kinetics of a Rh(I) system with chiral phosphite ligands. The rate is first-order in pressure and is optimum for a 2 1 ratio of phosphite Rh. These authors suggest that the reaction follows the olefin route, with the rate-limiting step being the oxidative addition of Hj, and that the active catalyst retains two phosphite ligands. The R configuration of the phosphite prixluces mainly the R-enantiomer from itaconic acid dimethyl ester. Calculations indicate that this comes from the major catalyst-substrate complex. 

On the other hand, Bolm et al. have reported, more recently, the use of BINOL-derived A -phosphino sulfoximines as ligands in the rhodium-catalysed hydrogenation of dimethyl itaconate and a-acetamidoacrylates, achieving excellent enantioselectivities of up to 99% ee (Scheme 8.12). In the main... 

A set of core-functionalized dendrimers was synthesized by Van Leeuwen et al. and one compound was applied in continuous catalysis. [45] The dendritic dppf, Xantphos and triphenylphosphine derivatives (Figures 4.22, 4.30 and 4.31) were active in rhodium-catalyzed hydroformylation and hydrogenation reactions (performed batch-wise). Dendritic effects were observed which are discussed in paragraph 4.5. The dendritic rhodium-dppf complex was applied in a continuous hydrogenation reaction of dimethyl itaconate. 

Fu has reported a planar-chiral bisphosphorus ligand 45 with a phosphaferrocene backbone. The ligand has provided enantioselectivity up to 96% ee in the hydrogenation of a-dehydroamino acid derivatives.99 Another planar-chiral ferrocene-based bisphosphorus ligand 46 has been reported by Kagan recently and enantioselectivity up to 95% ee has been obtained in the reduction of dimethyl itaconate.100... 

In contrast to the many successful examples for hydrogenation of the parent itaconic acid or its dimethyl ester, only a few ligands have been reported to be efficient for the hydrogenation of / -substituted itaconic acid derivatives. Rh complexes with chiral ligands such as MOD-DIOP,69,69a 69h BPPM,246 Et-DuPhos,247 and TangPhos116 are... 

A comparison of the activities for various catalyst derivatives shown in Figure 10.13 seems to prove that the ligand with the cyclohexyl residue leads to the most active catalyst for the hydrogenation of dimethyl itaconate. The catalyst containing the methyl derivative apparently exhibits the lowest activity. 

Table 10.2 Kinetic analysis of the asymmetric hydrogenation of dimethyl itaconate with derivatives of [Rh(PROPRAPHOS)-COD]BF4 (see Fig. 10.13).

Recently Togni et al. [19] focussed on the preparation of asymmetric dendrimer catalysts derived from ferrocenyl diphosphine ligands anchored to dendritic backbones constructed from benzene-1,3,5-tricarboxylic acid trichloride and adamantane-l,3,5,7-tetracarboxylic acid tetrachloride (e.g. 11, Scheme 11). In situ catalyst preparation by treatment of the dendritic ligands with [Rh(COD)2]BF4 afforded the cationic Rh-dendrimer, which was then used as a homogeneous catalyst in the hydrogenation reaction of, for example, dimethyl itaconate in MeOH. In all cases the measured enantioselectivity (98.0-98.7%) was nearly the same as observed for the ferrocenyl diphosphine (Josiphos) model compound (see Scheme 11). 

Kollner et al. (29) prepared a Josiphos derivative containing an amine functionality that was reacted with benzene-1,3,5-tricarboxylic acid trichloride (11) and adamantane-l,3,5,7-tetracarboxylic acid tetrachloride (12). The second generation of these two types of dendrimers (13 and 14) were synthesized convergently through esterification of benzene-1,3,5-tricarboxylic acid trichloride and adamantane-1,3,5,7-tetracarboxylic acid with a phenol bearing the Josiphos derivative in the 1,3 positions. The rhodium complexes of the dendrimers were used as chiral dendritic catalysts in the asymmetric hydrogenation of dimethyl itaconate in methanol (1 mol% catalyst, 1 bar H2 partial pressure). The enantioselectivities were only... 

Itaconic acid and its derivatives represent the only other alkene type which has so far been reduced with optical yields of over 90%. Using the usual cationic rhodium-diene (cod) precursor, a best optical yield of 94% was obtained with the diphosphine FPPM (59). The presence of triethylamine was necessary.267 With the related BPPM (Table 5), again in presence of triethyl-amine, optical yields up to 92% were achieved.268 [Rh(cod)(DIPAMP)]+ gave an optical yield of 88% for the dimethyl ester of itaconic acid, and 90% with a monoamide of a-methyleneglutaric acid.269... 

Chinchilla, R., Galindo, N., and Najera, C., Dimethyl 2-(tosylmethyl)fumarate. An allyl sulfone as electrophilic reagent for the synthesis of itaconate ester derivatives. Tetrahedron, 52, 1035, 1996. 

Stepwise substitution in the phenyl rings of phosphines such as BDPP creates new diastereomeric pairs due to chirality on phosphorus. In a detailed investigation into the hydrogenation of (Z)-a-acetamidocinnamic acid, its methyl ester and dimethyl itaconate, the catalyst was prepared from [Rh(cod)Cl]2 plus 2 equiv. of (2S,4S)-BDPP or its mono-, di-, tri-, or tetrasulfonated derivative (25-28) [93],... 

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