Acrylic acid derivatives examples

NMR spectroscopy of various nuclei has been used in the study of AB cements derived from various acids, including phosphoric acid and poly(acrylic acid). For example, NMR has been used in studies of dental silicate cement, i.e. the AB cement made from aqueous phosphoric add and powdered aluminosilicate glass (Wilson, 1978). In this cement, the... 

Types of compounds are arranged according to the following system hydrocarbons and basic heterocycles hydroxy compounds and their ethers mercapto compounds, sulfides, disulfides, sulfoxides and sulfones, sulfenic, sulfinic and sulfonic acids and their derivatives amines, hydroxylamines, hydrazines, hydrazo and azo compounds carbonyl compounds and their functional derivatives carboxylic acids and their functional derivatives and organometallics. In each chapter, halogen, nitroso, nitro, diazo and azido compounds follow the parent compounds as their substitution derivatives. More detail is indicated in the table of contents. In polyfunctional derivatives reduction of a particular function is mentioned in the place of the highest functionality. Reduction of acrylic acid, for example, is described in the chapter on acids rather than functionalized ethylene, and reduction of ethyl acetoacetate is discussed in the chapter on esters rather than in the chapter on ketones. 

Only limited successful examples of asymmetric hydrogenation of acrylic acids derivatives have included the use of chiral Rh complexes (Scheme 1.17). The diamino phosphine (28) utilizes selective ligation of the amino unit to a Rh center and also exerts electrostatic interaction with a substrate. Its Rh complex catalyzes enantioselective hydrogenation of 2-methylcinnamic acid in 92% optical yield [116], Certain cationic Rh complexes can attain highly enantioselective hydrogenation of trisubstituted acrylic acids [ 1171. 2-(6 -Methoxynaphth-2 -yl)acrylic acid is hydrogenated by an (.S ..S )-BIPNOR- Rh complex in methanol at 4 atm to give (.S)-naproxen with 98% ee but only in 30% yield [26]. 

The elimination/addition reaction already proceeded at room temperature when the dichloropropionic acid had been linked as an ester to the support, but required heating when an amide linkage had been chosen. When amines with low nucleophilicity were used, such as aniline or a-amino acid esters, higher reaction temperatures were also beneficial. Occasional by-products for this reaction sequence were acrylic acid derivatives or the corresponding hydrogenated products (2-thiopropionic acid derivatives). These by-products were usually formed when a very small excess of amine was used in the elimination/addition step. Both the thiols and the amines used in this reaction sequence could be polyfunctional, as illustrated by the examples sketched in Fig. 3. 

When the polymer is charged, the repulsive forces of the charges prevent an approach of the radicals, and the lifetime of the radicals increases dramatically. In the case of poly(acrylic acid), for example, the decay of the poly(acrylic) acid radicals is fast and follows the same kinetics as any radical derived from neutral polymers as long as the polymer is fully protonated (low pH) (Ulanski et al. 1996c). With increasing pH and concomitant dissociation of the polymer, however, the polymer assumes a rod-like shape, its segments become less flexible, and repulsive forces increasingly prevent their approach. Some radicals survive even for hours under such conditions. 

Drawn from these examples it is apparent that controlling the chemose-lectivity in inter-intermolecular Heck-Diels-Alder reactions of two different alkenes can be tedious if the alkenes show comparable reactivities. Nevertheless, the stepwise approach was realized in several other cases. In a synthesis of a derivative of cephalostatin 1 containing a central benzene instead of the pyrazine ring, Winterfeldt et al. linked two steroidal systems by a Heck coupling and subsequently performed high pressure Diels-Alder reactions of the conjugated diene with electron-deficient alkynes [34], Another example, reported by Hayashi et al., involves a selective Heck reaction of a bromoglu-cal with ethylene or acrylic acid derivatives followed by cycloadditions with maleic anhydride or N-phenylmaleimide [35]. 

Among the classic examples is the coupling-cyclization of alkynes with Z-f)-bromo acrylic acid derivatives invented by Negishi and Kotora [110] as a sequential access to the y-alkylidcncbulcnolide 140 in excellent yield (Scheme 53). The constitutional isomeric a-pyranone 141 is only formed in 4% yield. 

Enamines can be deprotonated with n-BuLi or f-BuLi if some stabilizing groups are present at the nitrogen or on the alkene. Some examples are /3-amino acrylic acid derivatives 68 2987,988, which have also been employed as /S-acyl vinyl anion equivalents858. 

In certain cases, carboxyl groups can be replaced by halide. Acrylic acid derivatives ArCH=CHCOOH, for example, react with 3 equivalents of Oxone in the pre-... 

As far as stereoselectivity is concerned, the key step is the Diels-Alder reaction—in each case the diene (cyclopentadiene, shown in black) adds across the dienophile, an acrylic acid derivative. As you would expect from what we said in Chapter 35, both reactions are diastereoselective in that they generate mainly the endo product. In the hrst example, that is all there is to say the product that is formed is necessarily racemic because all the starting materials in the reaction were achiral. 

A further development of the Reppe acrylic acid synthesis is the reaction, described in recent literature, of the noble metal-catalyzed carbonylation of higher acetylenes to give the corresponding acrylic acid derivatives. Thus, for example, the Pd-catalyzed carbonylation of propyne (eq. (10)) in the presence of methanol leads directly to methyl methacrylate [23]. Based on this work. Shell has developed a new production process for methyl methacrylate [24]. The propyne required can be isolated from the product streams from crackers, (cf. Section 2.3.2.3). 

The tetranuclear rhodium cluster Rh4(CO),2 has also been reported to catalyze the hydrocarbonylation of acrylic acid derivatives with isopropanol as hydrogen donor. As a typical example, ethyl acrylate reacts with CO and isopropanol... 

The polymer-bound 2-arylsulfonylaminomethyl acrylic acids derived from the three-component Baylis-Hillman reaction can also be used as templates for the synthesis of different core structures. Here, we present the alkylation of these templates as an example (Fig. 6.13). 

Silyloxycyclopropanecarboxylates are masked homoenolate equivalents which can also add to dimethyl(methylene)iminium salts. In one of several examples reported by Reissig and Lorey, methyl 2-f-butyl-2-(trimethylsilyloxy)cyclopropanecarboxylate and triflate salt (33) react to produce methylaminomethyl-y-oxo ester (64 Scheme 14). The reactive intermediate has not been precisely determined but is most likely a ring-opened enolate (63) or its silyl ketene acetal derivative. The reaction can also be performed using the chloride iminium salt (31) in the presence of TiCU, but the reproducibility is poor due to reduced solubility. The products of these reactions are convenient precursors to a-methylene-8-lactones and acrylic acid derivatives. 

Substituted phenyldiazonium salts have been used by Hoechst as precursors for palladium-catalyzed coupling with acrylic acid derivatives. FMDHCA (/ -fluoro-a-methyldihydrocinnamic acid) and its derivatives, for example, were also pre-... 

The acrylic acid derivative 460 was successfully used for asymmetric carbon-carbon bond formation to form 461, and in situ hydrolysis provided 462 with good selectivity.112 This stepwise aza-annulation process was completed by treatment with NH4OH, which led to the formation of 463. In the examples shown in Scheme 36, both reactions resulted in deracemization of the initial racemic ketone substrate through formation of the carbon-carbon bond. 

Chemical reactions with alkyd resins can take place via their hydroxyl or carboxyl groups as well as via the double bonds of the unsaturated fatty acids. Isocyanates, epoxy resins, or colophony, for example, may be reacted with the hydroxyl groups. The carboxyl groups can be reacted with polyamidoamines (reaction products formed from dimerized linoleic acid and ethylenediamine) to form thixotropic resins, or can react with hydroxy-functional silicone precondensates. The double bonds of the unsaturated fatty acids permit copolymerization with vinyl compounds [e.g., styrene or (meth)acrylic acid derivatives]. 

The intermolecular oxidative arylation of olefins has been reported in most cases with acrylic acid derivatives. This process could be developed as an alternative to the Heck reaction, which occurs with aryl halides. Several groups have reported versions of this oxidative C-C bond formation. Fujiwara reported intermolecular examples of this reaction catalyzed by palladium and copper (Equation 18.64). Intermolecular versions of this reaction have also been reported with ruthenium catalysts and as the oxidant. Other oxidative reactions in which electron-rich arenes add to olefins (Equation 18.66) have been reported as stoidiiometric steps of natural products syntheses, and later as a catalytic process. ... 

Another important example of an enantioselective reaction mediated by a chiral catalyst is the hydrogenation of 3-substituted 2-acetamido acrylic acid derivatives. 

Examples of pol5nners with dendrimer structures include amide amine dendrimers and phenyl ether dendrimers. The terminal amino group of an amide amine dendrimer may be allowed to react with acrylic acid derivatives or methacryUc acid derivatives to S)mthesize amide amine dendrimers having terminals of acrylic or methacrylic acid derivatives (44). 

The application of a different N-halogen source was described by Branco, Prab-hakar and coworkers [20]. In this case, acrylic acid derivatives underwent amination in the presence of bromamine-T to yield the corresponding aziridines as the major products. Aminobrominated side products were also observed in some cases. Scheme 4.3 shows a representative example for the oxidation of dimethyl acrylamide (Eq. (4.9)). The reactions were also investigated in the presence of stoichiometric amounts of palladium, as for example for methyl acrylate, which gave the corresponding aziridine as the only product [21]. The mechanism of this aziridination remains uncertain as both Pd(II) and Pd(IV) intermediates have been suggested, although without definite proof... 

Several other synthetic methods are also in principle feasible. For example, for the preparation of H-H poly(methyl methacrylate) the cyclopolymerization of meth-acrylic acid derivatives if directed exclusively to the five-membered ring formation (42), and for the preparation of H-H polymers of olefins disubstituted on one carbon atom, the Wurtz synthesis has become feasible. (Eqn. 6,7.)... 

Though SAP systems usually exhibit a better activity than biphasic systems, both are in most cases inferior to simple homogeneous reactions. The hydroformylation of methyl acrylate is an example of the entirely different behavior. Hydroformylation of acrylic acid derivatives can be of considerable industrial importance [140], as it gives mainly formylpropionic acids, which are viable precursors of methacrylate monomers and can be used for preparation of several important pharmaceuticals ... 

Isopropylidene alkylidenemalonates undergo copper-catalysed conjugate addition with Grignard reagents yields of between 80 and 86% are reported for seven examples. Direct lithiation of the acrylic acid derivative (10), followed by reaction with COg, gives the oxaloacetic acid monoester (11) (Scheme 8). ... 

Pd-catalyzed reactions tolerate a great variety of functional groups (5). Vinyl benzamide or vinyl anilin are examples obtained in good yields and at polymerization-grade purity. By substitution of ethylene with acrylic acid derivatives products with cinamic acid structures are obtained (d). 

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