Acrylonitrile Methyl Acrylate

Brar and Sunita [184] have reported the reactivity ratios (r) for the acrylonitrile]A)-methyl acrylate (M) monomer pair using the errors in variables model (EVM) [185, 186] with the use of a computer program written by O Driscoll and co-workers [187]. The primary structure factors monomer composition, diad/triad sequence distribution, conditional probabilities, and number-average sequence lengths of acrylonitrile-methyl acrylate copolymers were determined on the basis of C H -NMR analyses and compared with those calculated from reactivity ratios as determined from EVM program. The diad sequence calculated from C H)-NMR (proton decoupled C-NMR) spectra was correlated with the Tg of A/M copolymers. 

The acrylonitrile-methyl acrylate (A/M) copolymers of different monomer compositions were prepared by bulk polymerisation using free radical initiator (benzoyl peroxide). Terminal and penultimate reactivity ratios were calculated using the observed monomer triad sequence distribution. 

Sample No. A- Mole fraction in copolymer Triads Triad concentrations calculated horn Penultimate reactivity ratios (r) 

Reprinted with permission from A.S. Brar and A. Sunita, Journal of Polymer Science Part A Polymer Chemistry Edition, 1992, 30, 12, 2549. 

Triad sequence distributions were used to calculate diad concentrations, probability parameters, number average sequence lengths and the comonomer mole fractions in the copolymers. The experimental fractions of all the ten A centred and ten M centred triad cotactic sequences were found to be in excellent agreement with those calculated using the probabilities parameters. 

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Styrene Acrylonitrile Methyl acrylate Vinyl acetate... 

Acrylonitrile—methyl acrylate—iadene terpolymers, by themselves, or ia blends with acrylonitrile—methyl acrylate copolymers, exhibit even lower oxygen and water permeation rates than the iadene-free copolymers (110,111). Terpolymers of acrylonitrile with iadene and isobutjlenealso exhibit excellent barrier properties (112), and permeation of gas and water vapor through acrylonitrile—styrene—isobutjleneterpolymers is also low (113,114). 

The monomer pair, acrylonitrile—methyl acrylate, is close to being an ideal monomer pair. Both monomers are similar in resonance, polarity, and steric characteristics. The acrylonitrile radical shows approximately equal reactivity with both monomers, and the methyl acrylate radical shows only a slight preference for reacting with acrylonitrile monomer. Many acrylonitrile monomer pairs fall into the nonideal category, eg, acrylonitrile—vinyl acetate. This is an example of a nonideality sometimes referred to as kinetic incompatibiUty. A third type of monomer pair is that which shows an alternating tendency. 

O.JVI. Scott Sons. The O.M. Scott Sons Co. (Scotts) has developed a series of coated products which utilize copolymer blends of vinyHdene chloride copolymerized with methyl methacrylates, acrylonitriles, methyl acrylates, and/or vinyHdene—vinyl chloride monomers. 

In addition, Bamford, Jenkins and coworkers (19) previously reported on the behavior of occluded radicals in the heterogeneous polymerizations of acrylonitrile, methyl acrylate, methyl methacrylate and vinylidene chloride. From their electron spin resonance studies, they concluded that the degree of occlusion was ... 

A number of examples have been reported documenting the use of palladium phosphine complexes as catalysts. The dialkyl species [PtL2R2] (L2 = dmpe, dppe, (PMe3)2 R = Me, CH2SiMe3) catalyze the reaction of [PhNH3]+ with activated alkenes (acrylonitrile, methyl acrylate, acrolein).176 Unfunctionalized alkenes prove unreactive. The reaction mechanism is believed to proceed via protonation of Pt-R by the ammonium salt (generating PhNH2 in turn) and the subsequent release of alkane to afford a vacant coordination site on the metal. Coordination of alkene then allows access into route A of the mechanism shown in Scheme 34. Protonation is also... 

For the addition of ethylene, EtOAc as solvent was particularly advantageous and gave 418 in 60% yield (Scheme 6.86). The monosubstituted ethylenes 1-hexene, vinylcyclohexane, allyltrimethylsilane, allyl alcohol, ethyl vinyl ether, vinyl acetate and N-vinyl-2-pyrrolidone furnished [2 + 2]-cycloadducts of the type 419 in yields of 54—100%. Mixtures of [2 + 2]-cycloadducts of the types 419 and 420 were formed with vinylcyclopropane, styrene and derivatives substituted at the phenyl group, acrylonitrile, methyl acrylate and phenyl vinyl thioether (yields of 56-76%), in which the diastereomers 419 predominated up to a ratio of 2.5 1 except in the case of the styrenes, where this ratio was 1 1. The Hammett p value for the addition of the styrenes to 417 turned out to be -0.54, suggesting that there is little charge separation in the transition state [155]. In the case of 6, the p value was determined as +0.79 (see Section 6.3.1) and indicates a slight polarization in the opposite direction. This astounding variety of substrates for 417 is contrasted by only a few monosubstituted ethylenes whose addition products with 417 could not be observed or were formed in only small amounts phenyl vinyl ether, vinyl bromide, (perfluorobutyl)-ethylene, phenyl vinyl sulfoxide and sulfone, methyl vinyl ketone and the vinylpyri-dines. 

A similar method can be used for the addition of carbon tetrachloride to nonpolymerizable olefins (e.g., 1-octene, 2-octene, 1-butene, 2-butene) pure adducts are obtained in yields of over 90% if the components are allowed to react at 100° for 6 hours. Adducts of carbon tetrachloride with vinylic monomers (styrene, butadiene, acrylonitrile, methyl acrylate, etc.) can be prepared in good yields by substituting cupric chloride dihydrate in acetonitrile for ferric chloride hexahydrate and benzoin. 

Butadiene Styrene Methyl Methyacrylate Acrylonitrile Methyl Acrylate Vinyl Acetate Vinyl Chloride Q e... 

Confirmation was provided by the observation that the species produced by the photolysis of two different carbene sources (88 and 89) in acetonitrile and by photolysis of the azirine 92 all had the same strong absorption band at 390 nm and all reacted with acrylonitrile at the same rate (fc=4.6 x 10 Af s" ). Rate constants were also measured for its reaction with a range of substituted alkenes, methanol and ferf-butanol. Laser flash photolysis work on the photolysis of 9-diazothioxan-threne in acetonitrile also produced a new band attributed the nitrile ylide 87 (47). The first alkyl-substituted example, acetonitrilio methylide (95), was produced in a similar way by the photolysis of diazomethane or diazirine in acetonitrile (20,21). This species showed a strong absorption at 280 nm and was trapped with a variety of electron-deficient olefinic and acetylenic dipolarophiles to give the expected cycloadducts (e.g., 96 and 97) in high yields. When diazomethane was used as the precursor, the reaction was carried out at —40 °C to minimize the rate of its cycloaddition to the dipolarophile. In the reactions with unsymmetrical dipolarophiles such as acrylonitrile, methyl acrylate, or methyl propiolate, the ratio of regioisomers was found to be 1 1. 

Activated olefins (acrylonitrile, methyl acrylate), and halides such as allyl bromide and ethyl bromoacetate were used as electrophiles. In nonpolar solvents, the enamines (126a) were alkylated with high enantioselectivity, but poor chemical yields. In polar solvents, the chemical yields were acceptable, the optical yields poor 148). A similar reaction sequence has been used successfully for the synthesis of (+)-mesembrine (133)149 >. 

The relative reactivities of acrolein, acrylonitrile, methyl acrylate and methyl methacrylate have also been investigated by means of the Fukui function /+(r) and its condensed counterpart /c+18- These are local properties that help determine the preferred direction for a reagent to approach a substrate. In this instance they also mirror the relative reactivity of different substrates. Both functions correlated well with the experimental data, the LUMO density being a relatively good approximation to the Fukui function. A closely related local property is the condensed local softness s+(r), which also correlated well with the relative reactivities19. 

Ghosez and co-workers used standard electron-poor dienophiles (quinone, acrylonitrile, methyl acrylate, maleic anhydride) for their experiments, hence the choice of donor substituents to increase the electron density of the azadiene (Alder s rule). However, the intrinsically electron-deficient diene can only be made sufficiently nucleophilic by the presence of exceptionally good donors. The oxygen lone pair is relatively low-lying (a+ 2/3), so it does not confer sufficient reactivity for the oxime to react. AMI calculations validate this qualitative reasoning the oxime B HOMO lies at -9.47 eV versus -8.56 eV for A s HOMO. 

Similarly, acrylonitrile, methyl acrylate and acrylamide a-substituted with a benzyloxy group act as chain transfer agents during the polymerization of MMA, St, MA, and VA, which is due to the following fragmentation reaction [94] ... 

The alkylation of acyclic imines with electrophilic alkenes such as acrylonitrile, methyl acrylate or phenyl vinyl sulphone is also sensitive to steric effects and again, as a consequence, only mono-alkylation occurs398. The regioselectivity of the reaction in methanol varied from 100% attack at the more substituted a-position to 70% attack at the less substituted a -position depending upon the steric inhibition manifested and the stabilization of the competing secondary enamine tautomers (vide infra) (Scheme 204). In contrast, the reaction of butanone and other methyl ketone imines with phenyl vinyl ketone occurs twice at the more substituted a-position but this is then followed by a double cyclization process (Scheme 205). Four carbon-carbon bonds are formed sequentially in this one-pot synthesis of the bicyclo[2.2.2]octanone 205 from acyclic precursors399,400. 

Many systems of this type exist, examples of which are Cr+ or Fe3+--thiourea (tested in polymerizations of acrylonitrile, methyl acrylate and acrylamide [44] Ce3+ with alcohols, aldehydes, amines, phosphates and carboxylic acids [45] V5+ with glycols, Mn3+ with dicarboxylic acid and their derivatives [46] Fe3+ with benzoin [47] etc. 

Irradiation of quinoxalin-2(l//)-ones in the presence of electron-deficient alkenes such as acrylonitrile, methyl acrylate, or aryl alkenes gives regiospecifically [2 + 2] cycload-ducts. ... 

Alkenes 2-chloroacrylonitrile, acrylonitrile, methyl acrylate, ( )-but-2-ene, 2-methylpropene, 2,3-dimethylbut-2-ene. 

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