Acrylic acid, methyl ester carbonylation

Polyester fibers are composed of linear chains of polyethylene terephthalate (PET), which produces benzene, benzoic acid, biphenyl, and vinyl terephthalate on pyrolysis. Acrylic fibers comprise chains made up of acrylonitrile units, usually copolymerized with less than 15% by weight of other monomers, e.g., methyl acrylate, methyl methacrylate, or vinylpyrrolidone. Thermolysis results in the formation of acrylonitrile monomer, dimers, and trimers with a small amount of the copolymer or its pyrolysis product. In this case, the acrylic is Orion 28, which contains methyl vinyl pyridine as comonomer. Residual dimethyl formamide solvent from the manufacturing process is also found in the pyrolysis products. Cotton, which is almost pure cellulose, comprises chains of glucose units. The pyrolysis products of cellulose, identified by GC/MS, include carbonyl compounds, acids, methyl esters, furans, pyrans, anhydrosugars, and hydrocarbons. The major pyrolysis products are levoglucosan (1,6-anhydro-B-D-glucopyranose) and substituted furans. 

The Diels-Alder reactions of the methyl or ethyl ester of benzenesulfonylindole-2-acrylic acid with several l-alkoxycarbonyl-l,2-dihydropyridines are reported and only a single stereoisomer was obtained, as in the case of l-methoxy(ethoxy)-carbonyl-1,2-dihydropyridines. However, when the Diels-Alder reaction of 17 was carried out with 8g[R = (CHsjsC], a mixture of two stereoisomers 18gand25were obtained in a 1 1 ratio (65% total yield). The bulky rerr-butyl group creates sufficient steric interference with the indole ring to cause the loss of stereochemistry ... 

The application of 3-aminopropyl phosphine (3) [41,46] as a building block for incorporation into -COOH functionalized frameworks provides an excellent example of the utility of preformed primary phosphine frameworks (Scheme 8) [46]. The reactions involved Michael addition of ferf-butyl acrylate to malonic acid dimethyl ester to produce the intermediate adduct, 2-methoxycarbonyl-pentanedioc acid 5-ferf-butyl ester 1-methyl ester, which upon treatment with trifluro-acetic acid (TFA) produced the corresponding diester acid,2-methoxy-carbonyl-pentanedioic acid 1-methyl ester, in near quantitative yield. It is remarkable to note that the reaction of NH2(CH2)3PH2 (3) with the diester acid is highly selective as the -COOH group remained unattacked whereas the reaction occurred smoothly and selectively at the -COOMe groups to pro-... 

Enantioselective Michael addition of glycine derivatives by means of chiral phase-transfer catalysis has been developed to synthesize various functionalized a-alkyl-a-amino acids. Corey utilized 4d as catalyst for asymmetric Michael addition of glycinate Schiff base 1 to a,(3-unsaturated carbonyl substrates with high enantioselectivity (Scheme 2.15) [35,36]. With methyl acrylate as an acceptor, the a-tert-butyl-y-methyl ester of (S)-glutamic acid can be produced, a functionalized glutamic acid... 

Figure 12.20 demonstrates that Michael acceptors can also act as electrophiles towards enam-ines. Aqueous workup leads to the regeneration of the carbonyl group, and the Michael addition product C is obtained. An acrylic acid ester would react with the enamine A in complete analogy to the reaction of the acrylonitrile shown here the same holds true for the methyl vinyl ketone. 

When an aqueous organic solution of acetylene is treated with CO at tSO C and 30 atm, in the presence of a catalytic amount of NifCOK. acrylic acid is formed with a selectivity of about 90%. In the presence of alcohols, the corresponding acrylic ester is formed with a selectivity of about 85%. The interesting thing with methyl acetylene, is that the major product ( 80%) is methyl methacrylate. The preferred catalyst t undoubtedly based on nickel, althou other Group Vlll metal-carbonyl complexes (e.g. Fe(CO)s) will catalyze these reactions. 

The predominant conformation of a,P-unsaturated carbonyl compounds (aldehydes, ketones, esters) can vary when Lewis adds are coordinated to the carbonyl group, ft has been experimentally shown that the s-trans conformer of acrolein is more stable than the s-ds conformer, in the absence of any Lewis add. The two conformers are of almost equal stability in the case of acrylic acid or methyl acrylate 83] (Figure L21). The barriers between these conformers are low (4-9 kcal mol ). Interconversion is rapid, and the Curtin-Hammett principle ( 1.3) can be applied. 

Of course, the mechanism does not begin by abstraction of the proton at the methyl acrylate on an a position. This proton lacks sufficient acidity, because the corresponding anion is not able to enter into conjugation with the ester carbonyl. This happens because tiie anion occupies an orbital, which is perpendicular to the p orbitals of the carbonyl group. 

In formations of ternary complexes, the acceptor vinyl compound must have a double bond conjugated to a cyano or to a carbonyl group. Such acceptors are acrylonitrile, methacrylonitrile, acrylic and methacrylic esters and acids, methyl vinyl ketone, acrylamide, etc. Donor monomers are styrene, a-methyl styrene, butadiene, 2-3-dimethyl butadiene, isoprene, chloroprene, etc. 

The reaction is carried out in aqueous tetrahydrofuran, if acrylic acid is the desired product, or in aqueous alcohol if the ester is required. Nickel is introduced as bromide or iodide and is converted into carbonyl complexes under the reaction conditions, typically 200°C/100atm. One catalytic cycle which has been postulated for this process is shown in Fig. 12.18. Selectivity in the formation of acrylic acid from acetylene is better than 90%. Even from propyne, where anti-Markovnikov addition of [Ni]—H competes with the desired pathway, selectiv-ities of over 80% to methyl methacrylate H2C=C(Me)C02Me are achieved. The major by-product is methyl crotonate, MeCH=CHC02Me. 

There are various synthetic routes to introduce hydrocarbon long chains into amino acid-based surfactants. For example, a long-chain fatty acyl group is introduced on the amino part of amino acids by using an acid chloride. To obtain amino acid esters or amides, the carbonyl parts of amino acids are reacted with fatty alcohol or amines, respectively. For example, C-alkylation of an amino acid is obtained by the reaction of a-bromo fatty acid with ammonia or by a transmission reaction of the amino part of the amino ester with a stable Schiff base followed by deprotonation with a strong base. This is followed by alkylation with an alkyl halide. N-Alkylation of an amino acid is generally obtained by the reaction of fatty amines with monochloroacetic acid, methyl acrylate, or maleic acid or by the addition of 1,2-epoxy alkane to amino acids. 

Acrylic acid and its esters formed by the reaction as shown in eq. (19.39) had been produced until the end of the 1960s. But now they are produced by the oxidation of propene. For the production of acetic acid by the carbonylation of methyl alcohol shown in eq. (19.41), nickel catalysts were at first used, but afterwards the rhodium catalysts as described previously in Chapter 18 have been used. However, even now nickel catalysts are used in the production of propionic acid by the carbonylation of ethylene shown in eq. (19.40) [72]. 

The Michael reaction of nitriles with unsaturated carbonyl compounds was examined using the SA-NEtj catalyst As shown in Table 1.6, the SA-NEtj showed the highest catalytic activity for the Michael reaction of ethyl 2-cyanopropionate with ethyl acrylate to afibrd 2-cyano-2-methyl glutaric acid diethyl ester in 94% yield (entry 1). SiOj-NEtj was much less active under the reaction conditions (entry 2). Neither triethylamine nor sihca-alumina promoted the desired addition reaction (entries 3 and 4). Notably, the reaction scarcely proceeded with the... 

Methacryhc acid and its ester derivatives are Ctfjy -unsaturated carbonyl compounds and exhibit the reactivity typical of this class of compounds, ie, Michael and Michael-type conjugate addition reactions and a variety of cycloaddition and related reactions. Although less reactive than the corresponding acrylates as the result of the electron-donating effect and the steric hindrance of the a-methyl group, methacrylates readily undergo a wide variety of reactions and are valuable intermediates in many synthetic procedures. 

The Reppe process was commercialized in the 1950s. It involves the reaction pf acetylene, carbon monoxide, and an alcohol (methyl, ethyl, etc.) to give an acrylic ester (an acrylate). The process is carried out at 125°F and 15—30 psi in a nickel carbonyl/aqueous hydrochloric acid solution. The nickel carbonyl acts as both a catalyst and a secondary source of carbon monoxide. 

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