Acrylates reacting with

Evans s bis(oxazolinyl)pyridine (pybox) complex 17, which is effective for the Diels-Alder reaction of a-bromoacrolein and methacrolein (Section 2.1), is also a suitable catalyst for the Diels-Alder reaction of acrylate dienophiles [23] (Scheme 1.33). In the presence of 5 mol% of the Cu((l )-pybox)(SbF5)2 catalyst with a benzyl substituent, tert-butyl acrylate reacts with cyclopentadiene to give the adduct in good optical purity (92% ee). Methyl acrylate and phenyl acrylate underwent cycloadditions with lower selectivities. 

The first iridium-catalyzed reductive aldol reaction was reported in 2001.422 Methyl acrylate reacts with certain aldehydes and diethylmethylsilane with high enantio- and diastereoselectivies (Equation (69)). 

Photolytic. Polymerizes on standing and is accelerated by heat, light, and peroxides (Windholz et al., 1983). Methyl acrylate reacts with OH radicals in the atmosphere (296 K) and aqueous solution at rates of 3.04 x 10 and 2.80 x 10 cmVmolecule-sec, respectively (Wallington et al, 1988b). 

An exception was observed when alkyl acrylates were hydroformylated in SCCO2. Thus, n-butyl acrylate reacted with syngas at 30 bar and 80 °C to give aldehydes with an average TOF of 742 in the case of 1 and 1494 in the case of P(4-C6H4C6Fi3)3 (P/Rh = 6, olefin/Rh = 2700 - 2800). Similar observation was made with methyl acrylate, that is, the hydroformylation of acrylates with 1 was only ca. 2 fold slower, a sharp contrast to the over 20 fold difference when 1-hexene was hydroformylated using 1 and the same molecular phosphine. 

Methyl acrylate reacts with the enediamine 230 to yield the spiro-tetrahydroimidazo-pyridone 232 via the transient intermediate 231120. The reaction with methyl propiolate gives an analogous intermediate 233, which, however, is stable. It is transformed into the bicyclic dihydropyridone 234 by the action of methanol121 (equation 98). 

Michael Addition. Titanium imide enolates are excellent nucleophiles in Michael reactions. Michael acceptors such as ethyl vinyl ketone, Methyl Acrylate, Acrylonitrile, and f-butyl acrylate react with excellent diastereoselection (eq 21 ). - Enolate chirality transfer is predicted by inspection of the chelated (Z)-enolate. For the less reactive unsaturated esters and nitriles, enolates generated from TiCl3(0-j-Pr) afford superior yields, albeit with slightly lower selectivities. The scope of the reaction fails to encompass p-substituted, a,p-unsaturated ketones which demonstrate essentially no induction at the prochiral center. Furthermore, substimted unsamrated esters do not act as competent Michael acceptors at all under these conditions. 

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... 

Acrylonitrile and acrylates react with bromoform using base/phase-transfer catalyst to give exclusively the Michael adducts.The only exception is /er -butyl acrylate which, using bromoform/base/phase-transfer catalyst, yielded both products 1 and 2 their ratio depends on the catalyst structure (unlike the case of dichlorocarbene, tetramethylammonium chloride and benzo-15-crown-5 do not catalyze the selective formation of dibromocyclopropanes). 

However, methyl acrylate reacts with l-methyl-2-methylenecyclopropane to give a 43% yield of a 70 30 (cisjtrans) isomeric mixture of methyl 3-methyl-4-methylenecyclopentane-carboxylate. ... 

Various functionalized allylic halides have been used under the Luche conditions. Thus, 2-bromomethyl acrylate reacted with carbonyl compounds to give a-methylene-y-butyrolactones after acidic treatment of the alcoholic intermediate [102]. The reaction of ciimamyl chloride with aldehyde, unlike cinnamyl bromide which led to phenyl propene leaving the aldehyde unchanged [103], gave the diastereoisomeric y-products whereas the reaction with ketones gave mixtures of a- and y-products [104]. In the presence of zinc dust, l-chloro-3-iodopropene yielded the corresponding chlorohydrin when reacted with aldehydes or ketones under aqueous conditions. In this way, further treatment with base gave vinyl oxiranes whereas zinc in the presence of aqueous HBr led to (E)-buta-1,3-dienes (Scheme 21) [1051. 

The diastereoselectivity inherent to the Diels-Alder reaction can be seen in most of the examples in preceding reactions. The reaction is not, however, enantioselective since there is no facial control for intermolecular reactions (some facial control is available for intramolecular reactions). The ortho rule, the endo rule (secondary orbital interactions), and steric interactions provide some orientational control but facial control is also required for enantioselectivity. When ethyl acrylate reacts with 2-methyl-1,3-pentadiene, it can approach from the bottom as in 247A or from the top as in 247B. Clearly, the two products (248A and 248B) are mirror images and enantiomers. This lack of facial selectivity leads to racemic mixtures in all Diels-Alder cyclizations discussed to this point. 

Asymmetric synthesis of a-methylene-y-lactams The organozinc reagents derived from 2-(bromomethyl)acrylates react with imines to form a-methylene-y-lactams. Use of (S)-l-phenylglycine as the chiral auxiliary for the imine provides these products in >95% ee. 

Subsequent work in the Markd group has shown that under high-pressure reaction conditions, methyl acrylate reacts with 2-pyrone to yield a mixture of all four possible isomeric bicyclic lactones. The identification of the major reaction product as the syn-endo isomer 28 was established by X-ray crystallographic analysis. This methodology was subsequently employed to synthesize dialdehyde 29 as an entry into the tricyclic core of gibberellic acid and zizaene. ... 

Krische and co-workers have investigated the tertiary phosphine-catalyzed regjospecific allylic amination of MBH acetates through a tandem 5n2 -5n2 mechanism by using phthalimide derivatives as nucleophiles. When (1 )-C1-MeO-BIPHEP was used as a catalyst, the MBH adduct obtained from p-nitrobenzaldehyde and methyl acrylate reacted with phthalimide to give the allylic substituted product 297 in 80% yield with 56% ee (Scheme 3.126). ... 

The regiospecificity of the olefin cycloaddition reaction depends on the substituent groups present on the double bond. Thus, acrylonitrile and methyl acrylate react with various nitrile ylides to give only the 4-substituted regio-isomers (i.e., 16). Photocycloaddition of arylazirines to a-methylacrylo-nitrile and methyl methacrylate, on the other hand, give adducts of type 33 and 34 in a 3 2 ratio. ... 

The other class of compounds useful for degenerative transfer reactions are those with either C = C or C = S double bonds. Methacrylate derivatives have transfer rates similar to that of the propagation of methacrylates, and are successful only for the polymerization of methacrylates [35,36]. Due to steric effects the intermediate radical shown in Scheme 12 cannot react directly with monomer but only fragment. Unfortunately, mono substituted alkenes such as styrenes and acrylates react with the intermediate radicals and give branched structures, i.e., there is inefficient fragmentation. 

Traceless cleavage has also been achieved with an organoselenium resin. Resin-bound methyl 2-seleno acrylate reacted with an excess of azomethine yUde at room temperature (Scheme 11.11). N-Acylation of the pyrrolidines gave diverse resin-bound products that were released from the support by oxidative cleavage with hydrogen peroxide. A total of 13 substituted 2,5-dihydro-l//-pyrroles were produced with 57-74% yield. 

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