Acrylic acid olefin

There have been other approaches to obtaining rubber/metal adhesion besides primers or additives consisting of phenolics or epoxies plus halogenated elastomers. For example, carboxylated polymers (olefins and diolefins copolymerized with acrylic acid monomers) have shown excellent adhesion to metals. Very little carboxyl is necessary, and polymers with carboxyl contents as low as 0.1% show good adhesion when laminated to bare steel. When these materials possess... 

The Diels-Alder reaction of a diene with a substituted olefinic dienophile, e.g. 2, 4, 8, or 12, can go through two geometrically different transition states. With a diene that bears a substituent as a stereochemical marker (any substituent other than hydrogen deuterium will suffice ) at C-1 (e.g. 11a) or substituents at C-1 and C-4 (e.g. 5, 6, 7), the two different transition states lead to diastereomeric products, which differ in the relative configuration at the stereogenic centers connected by the newly formed cr-bonds. The respective transition state as well as the resulting product is termed with the prefix endo or exo. For example, when cyclopentadiene 5 is treated with acrylic acid 15, the cw fo-product 16 and the exo-product 17 can be formed. Formation of the cw fo-product 16 is kinetically favored by secondary orbital interactions (endo rule or Alder rule) Under kinetically controlled conditions it is the major product, and the thermodynamically more stable cxo-product 17 is formed in minor amounts only. 

Much like the oxidation of propylene, which produces acrolein and acrylic acid, the direct oxidation of isobutylene produces methacrolein and methacrylic acid. The catalyzed oxidation reaction occurs in two steps due to the different oxidation characteristics of isobutylene (an olefin) and methacrolein (an unsaturated aldehyde). In the first step, isobutylene is oxidized to methacrolein over a molybdenum oxide-based catalyst in a temperature range of 350-400°C. Pressures are a little above atmospheric ... 

Acrylates and Methacrylates Acrylic acid or Methacrylic acid + Alcohols (C3 or C4 olefins)... 

Conjugated olefinic systems have also been used in reaction with phosphorus-halogen species. For example, methylphosphonic dichloride adds regioselectively to acrylic acid in the presence of phosphorus trichloride (used as solvent), to produce the acid chloride 3-phosphonopropionyl chloride (Equation 4.35).158... 

One of the most important challenges in the modern chemical industry is represented by the development of new processes aimed at the exploitation of alternative raw materials, in replacement of technologies that make use of building blocks derived from oil (olefins and aromatics). This has led to a scientific activity devoted to the valorization of natural gas components, through catalytic, environmentally benign processes of transformation (1). Examples include the direct exoenthalpic transformation of methane to methanol, DME or formaldehyde, the oxidation of ethane to acetic acid or its oxychlorination to vinyl chloride, the oxidation of propane to acrylic acid or its ammoxidation to acrylonitrile, the oxidation of isobutane to... 

Type II (slow homodimerization) Styrene, allylstannanes" Styrene, 2° allylic alcohols, vinyl dioxolanes, vinyl boronates Styrenes (large ortho substit.) " " 2° allylic alcohols, vinyl epoxides, unprotected 3° allylic alcohols, acrylates, acrylamides, acrylic acid, acrolein, vinyl ketones, vinyl boronates perfluorinated alkane olefins ... 

A hydride of vitamin B12 coenzyme has been prepared and found to add to activated olefins (acrylic acid) and acetylene (56). 

To 0.2 mole of an olefin dissolved in 30 ml of glacial acetic acid is added 19.5 gm (0.3 mole) of sodium azide in 75 ml of water. The addition to acrolein and jf -nitrostyrene underwent rapid addition, requiring cooling with an ice-salt bath and slow addition of the sodium azide. Addition to methyl acrylate, acrylic acid, and acrylonitrile required 1-3 days at room temperature, a-vinyl pyridine and mesityl oxide required heating for 24 hr on a steam bath. Other olefins underwent no reaction even after 7 days of heating and were recovered unchanged. 

Hirai et al.129 studied the hydrogenation of olefins catalyzed by poly(acrylic acid)-Rh(II) complexes in homogeneous solutions. The catalytic activity of the polymer-Rh complex was about 103 times that of the acetato-Rh complex. When olefins having another functional group, such as diallylether, allylaldehyde, and cyclohexene-1 -one, were used as the substrates, the olefinic bond was preferentially hydrogenized by the polymer-Rh complex. The polymer ligand was presumed to exercise a steric effect. 

Catalytic oxidation and ammoxidation of lower olefins to produce a,/3-unsaturated aldehyde or nitrile are widely industrialized as the fundamental unit process of petrochemistry. Propylene is oxidized to acrolein, most of which is further oxidized to acrylic acid. Recently, the reaction was extended to isobutylene to form methacrylic acid via methacrolein. Ammoxidation of propylene to produce acrylonitrile has also grown into a worldwide industry. 

During the history of a half century from the first discovery of the reaction (/) and 35 years after the industrialization (2-4), these catalytic reactions, so-called allylic oxidations of lower olefins (Table I), have been improved year by year. Drastic changes have been introduced to the catalyst composition and preparation as well as to the reaction process. As a result, the total yield of acrylic acid from propylene reaches more than 90% under industrial conditions and the single pass yield of acrylonitrile also exceeds 80% in the commercial plants. The practical catalysts employed in the commercial plants consist of complicated multicomponent metal oxide systems including bismuth molybdate or iron antimonate as the main component. These modern catalyst systems show much higher activity and selectivity... 

Many substances can be partially oxidized by oxygen if selective catalysts are used. In such a way, oxygen can be introduced in hydrocarbons such as olefins and aromatics to synthesize aldehydes (e.g. acrolein and benzaldehyde) and acids (e.g. acrylic acid, phthalic acid anhydride). A selective oxidation can also result in a dehydrogenation (butene - butadiene) or a dealkylation (toluene -> benzene). Other molecules can also be selectively attacked by oxygen. Methanol is oxidized to formaldehyde and ammonia to nitrogen oxides. Olefins and aromatics can be oxidized with oxygen together with ammonia to nitriles (ammoxidation). 

Nickel(0)-catalyzed codimerization of methylenecyclopropanes with electron-deficient olefines are highly regiospedfic, but show a rather poor stereoselectivity. Thus the asymmetric nickel(0)-catalyzed codimerization of methylenecyclopropanes with the chiral bomane derivatives of acrylic acid leads to the optically active 3-methylenecyclopen-... 

In order to improve the physical properties of HDPE and LDPE, copolymers of ethylene and small amounts of other monomers such as higher olefins, ethyl acrylate, maleic anhydride, vinyl acetate, or acrylic acid are added to the polyethylene. For example, linear low density polyethylene (LLDPE), although linear, has a significant number of branches introduced by using comonomers such as 1-butene or 1-octene. The linearity provides strength, whereas branching provides toughness. 

Palladium complexes of chitin and chitosan have been shown to be active, selective, and stable catalysts for the hydrogenation of olefins, acrylic acid, nitrobenzene etc. at room temperature. Their catalytic activities can be controlled by changing the pH of the solution 90). 

A range of aromatic alkenes and acrylic acid derivatives have been converted into benzyl alcohols and a-hydroxyalkanoic acids in good yields by a reductive oxidation process. This reaction is accomplished by reaction with oxygen and triethylsilane with a cobalt(II) catalyst, followed by treatment with trialkyl phosphites (equation 30)154. The aromatic olefins may also be converted into the corresponding acetophenone in a modified procedure where the trialkyl phosphite is removed155. In a similar reaction 2,4-alkadienoic acids are converted into 4-oxo-2-alkenoic acids156. 

Similar to alkenyliodonium salts (see Sect. 6.3), aryliodonium salts are highly reactive substrates in Heck-type olefination and other palladium-catalyzed coupling reactions. Aryliodonium salts can serve as very efficient reagents in the palladium-catalyzed arylations of acrylic acid 101 [75], organotin compounds 102 [76], sodium tetraphenylborate 103 [77], and copper acetylide 104 [78] (Scheme 45). 

Yang, J.S. and Hsiue, G.H. (1997) Selective olefin permeation through Ag(I) contained silicone rubber-graft-poly(acrylic acid) membranes. Journal of Membrane Science, 126, 139. 

Further examples of attempts to replace olefins by alkanes as a starting materials, as in the maleic anhydride process, are the development of processes for selective oxidation and ammoxidation. Examples are processes for acrolein, acrylic acid (Table 2, entry 19) and acrylonitrile (Table 2, entry 20) using propane as a feedstock... 

The most widely used version of the Heck reaction is the coupling of aryl bromides or iodides with activated olefins such as styrene or acrylic acid derivatives, using conditions first described by Spencer [18], The catalysts are generated in situ by combining Pd(OAc)2 with two to four equivalents of triphenyl- or tri-o-tolyl-phosphine. Triethylamine, K2C03, NaHC03, or NaOAc are often used as the base. 

Milstein et al. found that Pd complexes with chelating alkylphosphines such as bis(diisopropylphosphino)butane (dippb) efficiently catalyze the olefmation of aryl chlorides with styrenes in the presence of elemental zinc [29]. Unfortunately, these electron-rich phosphines are apparently incompatible with electron-poor olefins such as acrylic acid derivatives. The latter were successfully coupled with activated chloroarenes by Herrmann et al., who used palladacycles or Pd-catalysts with heterocyclic carbenes [30]. 

The Monsanto group also extended their studies to other substrates (particularly a,/3-unsaturated acids) and other phosphines. In these later experiments, they generated the catalyst in situ, as the Horner group had done. A methanol solution containing an a-substituted acrylic acid and a trace amount of triethyla-mine was then added, and hydrogenations were carried out at 30 atm H2 and 60°C. For various combinations of olefin and chiral ligand, optica] purities ranged from 3 to 21% (Fig. 6). 

South Africa. Sasol produces many products from coal-derived syngas, including ethylene, propylene, a-olefins, alcohols, and ketones. They have also increased their production of methanol, synthetic lubricants, detergent alcohols, acrylic acid and acrylates, oxo-alcohols, styrene and polystyrene, propylene oxide, and propylene glycol. 

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