Methyl acrylate nucleophilic attack

Sulfides were also involved in a unique three-component, stereospecific Michael addition. The reaction described in Scheme 29 can be explained as follows regiospecific addition of the nucleophile to the exocyclic double bond of the a-methylenecyclopentenone, followed by trapping of the resulting enolate by methyl acrylate, and attack of the anion thus formed on the endocyclic double bond of the cy-clopentenone moiety to result, after protonation, in the bicyclo[2.2.1]heptan-6-one as a single stereoisomer (68% overall yield Scheme 29). 

As depicted in Scheme 11, ylides 39 derived from 4-methyl-[l,2,3]triazolo[l,5- ]pyridine react with Michael acceptors, which, upon nucleophilic attack at C3 and ring opening, lead to nucleophilic displacement of nitrogen. The intermediate diradical led to a mixture of compounds, including alkenes and a cyclobutane derivative when methyl acrylate was used, and the indolizine 40 with methyl propiolate as the electrophile <1998T9785>. Heating 4-methyl triazolopyridine with benzenesulfonyl chloride in acetone also confirmed decomposition via a radical pathway. 

Polymerizations of vinyl ketones such as methyl vinyl ketone are also complicated by nucleophilic attack of the initiator and propagating carbanion at the carbonyl group although few details have been established [Dotcheva and Tsvetanov, 1985 Hrdlovic et al., 1979 Nasrallah and Baylouzian, 1977]. Nucleophilic attack in these polymers results in addition, while that at the ester carbonyl of acrylates and methacrylates yields substitution. The major side reaction is an intramolecular aldol-type condensation. Abstraction of an a-hydrogen from a methyl group of the polymer by either initiator or propagating carbanion yields an a-carbanion that attacks the carbonyl group of the adjacent repeat unit. 

In 1969 Yamada and coworkers reported the first in a series of investigations on the alkylation of chiral enamines, derived from L-proline esters, with methyl acrylate and acrylonitrile170. The enamines were prepared under the usual azeotropic conditions but were not distilled since this resulted in cyclization, by nucleophilic attack of the enamine on the ester function, or partial racemization171. Optical yields were found to be... 

One case, however, is clear—ammonia and amines react with ordinary esters to give amides, and it is known that the attack at the carbonyl group is ratedetermining and effectively irreversible above pH 7. Ammonia (neutral and therefore a relatively soft nucleophile) reacts in methanol with methyl acrylate 4.80 kinetically at the 3 position to give the primary amine 4.81, and reaction continues in the same sense to give successively the secondary amine 4.82 and tertiary amine 4.83. 

The more a carbonyl group is like that of protonated acrolein (Fig. 4.12), the more likely it is that all nucleophiles will attack directly at the carbonyl carbon atom. In agreement with this perception, and in contrast to its behaviour with methyl acrylate, ammonia reacts with acryloyl chloride at the carbonyl carbon atom to give acrylamide. 

A cyclopentadienylcopper-fcr/-butyl isocyanide complex catalyzes the Michael addition of dimethyl methylmalonate to acrylonitrile at room temperature to give an S6% yield of the adduct 249). As the CU2O—BNC complex can also catalyze the addition of indene to methyl acrylate, the intermediate is most likely an organocopper complex. The reactions and kinetic data support the mechanism given by Eq. (118) to (120), involving metalation and nucleophilic attack by the carbanion on the olefin within the complex. Displacement of a solvent ligand by the olefin and coordination of the latter to the copper species are essential features of the mechanism. The rate of reaction is decreased if the compound with the... 

The reaction of poly(methyl acrylate)-Br with 2-aminoethanol was expected to result in multiple substituted products. This result was ascribed to the fact that after the substitution of the bromine by 2-aminoethanol, formation of a six-membered ring could occur (Scheme 18). Afterwards, ring opening by attack of a second 2-aminoethanol molecule could lead to the double-substituted product. The a-bromo poly(methyl acrylate) could be suppressed by using 4-aminobutanol instead of 2-aminoethanol as a nucleophile, without side reactions (Scheme 18). For example, the yield of functionalization of poly( -butyl acrylate) with 5-amino-l-pentanol is close to 96% [197]. 

Ammonia, a soft nucleophile for being neutral, reacts with methyl acrylate 100 in methanol in conjugate manner to give the primary amine 101. The reaction continues in the same sense and the secondary amine 102 and the tertiary amine 103 are formed successively [39]. It is to be noted that ammonia, and other primary and secondary amines, do not react with simple esters to form amides. Combine this with the known observation that attack at the carbonyl group is irreversible and also rate determining [40], the above conjugate addition must necessarily be a product of kinetic control, supported by HOMO-LUMO interaction. 

Methyl 2-haloacrylate and 2-chloroacrylonitrile (84,187) react with triethyl phosphite to give the 3-phosphonates rather than the 2-phos-phonates. Nucleophilic attack by phosphite in the beta position of Michael acceptors in general and acrylate esters in particular has been " established recently for many compounds (cf. Section V-C-2). Coover, McCall, and Dickey postulate that the intermediate thus formed stabi-... 

Since an amide nitrogen is far less basic than that of an aliphatic amine, amides do not displace alkene from palladium. The N atom of an amide is thus able to attack alkenes coordinated to Pd(II) to give vinyl amides, according to Scheme 1. Given in Table 1 is an example of the amidation of alkenes. The amidation can be made catalytic by using a combination of CuCl and O2 in the presence or absence of hexamethylphosphoramide (HMPA). The use of O2 alone also makes the reaction catalytic. The amidation does not proceed well with simple alkenes however, electron-deficient alkenes such as methyl acrylate and vinyl ketones undergo an effective catalytic amidation. Note that cyclic carbamates, because of the higher nucleophilicity of the N atom, are more reactive than cyclic amides. 

For attack of F on acrylic acid, first a hydrogen bonded complex is formed which then proceeds to the transition state and then to a stable carbanion. The methyl in the methacrylic acid reduces stabilization of the carbanion as predicted. Subsequent studies using ammonia as the nucleophile indicated that attack proceeded by a rate-determining intramolecular proton transfer from the nucleophile to the ligand, assisted by a discrete water molecule that acts as a catalyst17. They predicted that acrolein underwent 1,4-addition, acrylic acid either 1,2- or 1,4-addition and acrylonitrile 1,2-addition. 

---