Itaconic acid ester

The bicontinuous-microemulsion polymerization technique has also been used to develop novel proton exchange membranes (PEM) for fuel cell evaluation [97]. A series of hydrocarbon-based membranes were prepared based on the formulation shown in Fig. 5, with additional ionic vinyl monomers such as VB-SLi or bis-3-sulfopropyl-itaconic acid ester. After polymerization, the membranes were treated with dilute H2SO4 (0.5 M) to convert them to PEM membranes. The good performance of these PEM membranes in a single fuel cell is illustrated in Fig. 9. 

The amide group is superior to the ester as a directing group (equation 4).i5i. 52 The cationic rhodium complex (15) catalyzes the hydrogenation of 3-substituted itaconic acid esters with high diastereoselectivity. When a chiral rhodium complex is employed, effective kinetic resolution occurs. 

Scheme 6 Process for itaconic acid ester hydrogenation (BASF)...

Using itaconic acid esters as the unsaturated polymerizable compounds [22], it is possible to obtain polymers containing a pair of mesogenic fragments in each monomeric unit (cf. Fig. 6.3b) ... 

Stereoselective hydrogenation of itaconic acid esters Rhodium- organic catalyst Improved selectivity, high rate 45... 

With 56g as the heterogeneous catalyst, asymmetric hydrogenation of a-dehydroamino acid esters 48b and 48c, enamide 50a, and itaconic acid ester 57 were performed in toluene at room temperature under 40 atm of H2 to afford the corresponding products with full conversion in 90-97% ee, which were comparable or even superior to those obtained with their homogeneous counterpart (MonoPhos)2/Rh(I). Upon completion of the reaction, the catalyst... 

White crystals m.p. 162-164 C. ll can be prepared by the fermentation of sugar with the mould Aspergillus lerreus or by healing citra-conic anhydride with water at ISO C. Electrolysis of the potassium salt in solution gives allene. Itaconic acid is used as a comonomer in plastics its esters are polymerized to lubricating oils and plasticizers. 

Itaconic acid, anhydride, and mono- and diesters undergo vinyl polymerization. Rates of polymerization and intrinsic viscosities of the resulting homopolymers ate lower than those of the related acrylates (see Acrylic ester polymers) (8,9). 

Condensation with Aldehydes and Ketones. Succinic anhydride and succinic esters in the presence of different catalysts react in the gas phase with formaldehyde to give citraconic acid or anhydride and itaconic acid (94—96). Dialkyl acyl succinates are obtained by reaction of dialkyl succinates with C 4 aldehydes over peroxide catalysts (97). 

Hydride-promoted reactions are also well known, such as the acrylic and vinylacrylic syntheses (examples 7-10, Table VII). Some less-known compounds, which form in the presence of halide ions added to tetracar-bonylnickel, have been described by Foa and Cassar (example 11, Table VII). Reaction of allene to form methacrylates, and of propargyl chloride to give itaconic acid (via butadienoic acid), have been reported (examples 13 and 14, Table VII). 1,5-Hexadiene has been shown to be a very good substrate to obtain cyclic ketones in the presence of hydrogen chloride and tetracarbonylnickel (example 15, Table VII). The latter has also been used to form esters from olefins (example 16, Table VII). In the presence of an organic acid branched esters form regioselectivity (193). 

In the early 1990s, Burk introduced a new series of efficient chiral bisphospholane ligands BPE and DuPhos.55,55a-55c The invention of these ligands has expanded the scope of substrates in Rh-catalyzed enantioselective hydrogenation. For example, with Rh-DuPhos or Rh-BPE as catalysts, extremely high efficiencies have been observed in the asymmetric hydrogenation of a-(acylamino)acrylic acids, enamides, enol acetates, /3-keto esters, unsaturated carboxylic acids, and itaconic acids. 

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... 

Table 7 Asymmetric hydrogenation of itaconic acid or dimethyl ester...

The enantioselective hydrogenation of a,fj- or / ,y-unsaturated acid derivatives and ester substrates including itaconic acids, acrylic acid derivatives, buteno-lides, and dehydrojasmonates, is a practical and efficient methodology for accessing, amongst others, chiral acids, chiral a-hydroxy acids, chiral lactones and chiral amides. These are of particular importance across the pharmaceutical and the flavors and fragrances industries. 

When assessing catalytic results reported for new ligands, one must bear in mind that their quality and relevance differ widely. For most new ligands only experiments with selected model test substrates carried out under standard conditions are available, and very few have already been applied to industrially relevant problems. The test substrates for alkenes used most frequently are Aceta-mido Cinnamic Acid (ACA) or its methyl ester (MAC), Methyl Acetamido Acrylate (MAA), ITaconic Acid or DiMethyl ITaconate (ITA, DMIT) and selected aryl enamides (Fig. 25.3). 

Many chiral phosphorus ligands have shown excellent reactivities and enantio-selectivities in the Rh-catalyzed hydrogenation of itaconic acids or esters. Some successful (>95% ee) hydrogenations of itaconic acid or its dimethyl ester with different chiral phosphorus ligands are listed in Table 26.7. High reactivity is observed with electron-rich phosphane ligands such as BICHEP [7c[. 

In contrast to the many successful examples of hydrogenation of the parent itaconic acid or its dimethyl ester, only a few ligands have been reported to be... 

Table 28.3 Enantioselective hydrogenation of itaconic acid and its dimethyl ester.

In the studies conducted by Reetz, rhodium catalysts based on mixtures of monodentate phosphites, monodentate phosphonites and combinations of the two were screened in the enantioselective hydrogenation of a- and /9-N-acetyl-de-hydroamino acid esters, enamides and dimethyl itaconate [40], and a number of the more striking positive results are listed in Table 36.3. An enhanced ee-value was found mostly with combinations of two phosphonites, or one phosphonite and one phosphite, in particular when one of the ligands carries a bulky substituent and the other a small one. 

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