Methyl acrylate arylation

Jap-KIingermarm reactions, 4, 301 oxidation, 4, 299 reactions, 4, 299 synthesis, 4, 362 tautomerism, 4, 38, 200 Indole, 5-amino-synthesis, 4, 341 Indole, C-amino-oxidation, 4, 299 tautomerism, 4, 298 Indole, 3-(2-aminobutyl)-as antidepressant, 4, 371 Indole, (2-aminoethyl)-synthesis, 4, 278 Indole, 3-(2-aminoethyl)-synthesis, 4, 337 Indole, aminomethyl-reactions, 4, 71 Indole, 4-aminomethyl-synthesis, 4, 150 Indole, (aminovinyl)-synthesis, 4, 286 Indole, 1-aroyl-oxidation, 4, 57 oxidative dimerization catalysis by Pd(II) salts, 4, 252 Indole, 1-aroyloxy-rearrangement, 4, 244 Indole, 2-aryl-nitration, 4, 211 nitrosation, 4, 210 synthesis, 4, 324 Indole, 3-(arylazo)-rearrangement, 4, 301 Indole, 3-(arylthio)-synthesis, 4, 368 Indole, 3-azophenyl-nitration, 4, 49 Indole, 1-benzenesulfonyl-by lithiation, 4, 238 Indole, 1-benzoyl photosensitized reactions with methyl acrylate, 4, 268 Indole, 3-benzoyl-l,2-dimethyl-reactions... 

Kochi (1956a, 1956b) and Dickerman et al. (1958, 1959) studied the kinetics of the Meerwein reaction of arenediazonium salts with acrylonitrile, styrene, and other alkenes, based on initial studies on the Sandmeyer reaction. The reactions were found to be first-order in diazonium ion and in cuprous ion. The relative rates of the addition to four alkenes (acrylonitrile, styrene, methyl acrylate, and methyl methacrylate) vary by a factor of only 1.55 (Dickerman et al., 1959). This result indicates that the aryl radical has a low selectivity. The kinetic data are consistent with the mechanism of Schemes 10-52 to 10-56, 10-58 and 10-59. This mechanism was strongly corroborated by Galli s work on the Sandmeyer reaction more than twenty years later (1981-89). 

Scheme 34 Cu-catalyzed asymmetric reaction of aryl methyl ketones and methyl acrylate...

Matsuda et al. applied aryl isocyanates as acceptors in reductive couplings to methyl acrylate (Scheme 44) [77]. The cationic Rh complex [Rh(COD) P(OPh)3 2]OTf (1 mol%) and Et2MeSiH (200 mol%) catalyze the reaction in refluxing CH2C12 to provide products of hydrocarbamoylation,... 

Equation 11.8 Arylation of methyl acrylate under phase-transfer conditions. (TBAB = tetrabutyl ammonium bromide)... 

The vinyl triflate of Komfeld s ketone has been subjected to Heck reactions with methyl acrylate, methyl methacrylate, and methyl 3-(Af-rerf-butoxycarbonyl-lV-methyl)amino-2-methylenepropionate leading to a formal synthesis of lysergic acid [259]. A similar Heck reaction between l-(phenylsulfonyl)indol-5-yl triflate and dehydroalanine methyl ester was described by this research group [260]. Chloropyrazines undergo Heck couplings with both indole and 1-tosylindole, and these reactions are discussed in the pyrazine Chapter [261], Rajeswaran and Srinivasan described an interesting arylation of bromomethyl indole 229 with arenes [262]. Subsequent desulfurization and hydrolysis furnishes 2-arylmethylindoles 230. Bis-indole 231 was also prepared in this study. 

Arylation of activated double bonds with diazonium salts in the presence of copper catalysts is known as the Meerwin reaction. The reaction is postulated to either proceed through an organocopper intermediate or through a chlorine atom transfer from chiral CuCl complex to the a-acyl radical intermediate. Brunner and Doyle carried out the addition of mesityldiazonium tetrafluoroborate with methyl acrylate using catalytic amounts of a Cu(I)-bisoxazoline ligand complex and were able to obtain 19.5% ee for the product (data not shown) [79]. Since the mechanism of the Meerwin reaction is unclear, it is difficult to rationalize the low ee s obtained and to plan for further modifications. 

Brown and coworkers [22] have studied the Pd-catalyzed Heck arylation of methyl acrylate via P and NMR (see Figure 1.7). Reaction of the aryl iodide complex 23 with AgOTf (THF, 195 K) gives the THF and aquo-complexes 24 and 25, respectively, which were detected via P NMR below 203 K. Addition of HjO to the sample shifts the equilibrium towards 25, pointing to an existing fast exchange between solvates 24 and 25. Reaction of 24/25 with 3- C labeled methyl acrylate (20-fold excess, 213 K) affords the insertion product 26. Warming to 233 K leads to the formation of 27, which is in turn converted into 29, stable to... 

Recently, arylation of methyl acrylate was intensively studied [15-21], Phenylation with Ph3BiX2 was largely affected by X, as shown in Scheme 6. PdCl2 as well as Pd2(dba)3 (dba = dibenzylideneacetone) are efficient catalysts, whereas the addition of phosphine ligands retards the phenylation e.g., PdCl PPh3 afforded no... 

The authors showed that the above reaction carried out in 7V-hexyl-pyridinium salts gave higher yields than imidazolium salts, that the addition of a phosphine ligand to Pd reduced the yield in pyridinium salts, and that higher reaction temperatures were required to obtain high yields. Howarth and Dallas studied the use of [bmimJpF ] as an IL solvent for the reaction of aryl halides and methyl acrylate. They found that the yields of the products were comparable with that obtained with DMF, and that the solvent and catalyst could be reused several times. 

Similarly, Uneyama and Watanabe (91TL1459) have reported the synthesis of trifluoromethylated AI-aryl-1-azabutadienes by palladium-catalyzed coupling of trifluoroacetimidoyl iodides with alkenes as well as the transformation of the azadiene derived from methyl acrylate into the corresponding 4-methoxycarbonyl-2-trifluoromethylquinoline in quantitative yield. 

Huisgen, Szeimies, and Mobius have studied the addition reactions of aryl azides to a,/S-unsaturated esters and nitriles.1 4 Methyl acrylate (73) reacts with aryl azides to form l-aryl-4-carbomethoxy-A -triazolines in agreement with the orientation rule based on electronic effects. These A -triazolines are completely converted by base catalysis into the ring-opened isomer. Thus l-phenyl-4-carbomethoxy-A2-triazo ine (74) gives, in the presence of triethylamine at room temperature, methyl 3-aniline-2-diazopropionate (75). The A2-triazolines as well as the a-diazoesters are thermolabile. 74 is converted into l-phenyl-2-carbomethoxyaziridine (76) and 75 gives methyl 3-anilinoacrylate (77) as thermolysis product.262... 

When the carbopalladation of the bicyclopropylidene is performed in the presence of methyl acrylate, the reaction takes a different course (Scheme 8.34) [79]. The 1,3-diene intermediate 75 reacts in situ with the dienophile to give the spiro[2.5]octane derivative 76. An extension of this cascade Heck-Diels-Alder reaction involving l,3-dicyclopropyl-l,2-propadiene as the alkene partner, an alkenyl or aryl halide and a dienophile has been reported [80]. 

Shi and Xu reported that the chiral amine catalyst 142 also performs quite efficiently in the related addition of N-tosyl aryl imines to methyl vinyl ketone (MVK), to methyl acrylate, and to acrylonitrile (Scheme 6.61) [155]. As shown in Scheme 6.61, enantiomeric excesses > 95% were achieved for several />-N-tosylamino enones 147 obtained by addition of aryl imines (146) to MVK, > 80% for addition to methyl acrylate, and 55% ee (max.) for addition to acrylonitrile (not shown in Scheme 6.61). Reaction times were typically 1-3 days. N-Sulfonylimines derived from aliphatic aldehydes gave rise to complex product mixtures. Under the reaction conditions shown in Scheme 6.61 addition of p-nitrobenzaldehyde to MVK proceeded with only 20% ee. 

The Heck reaction continues to be a popular route to tetrahydroisoquinolines. Intramolecular reaction of 2-iodo-Ar-phenylbcnzamidc with methyl acrylate yields l-oxotetrahydroisoquinoline-3-carboxylic acids <1997J(P1)2577>, while the intramolecular reaction of an aryl bromide with an enaminone also forms the tetrahydroisoquinoline ring <1997TL2829>. 

General Procedure for the / -ICD-Mediated Asymmetric Aza-MBH Reaction ofTosyl Aryl Aldimines and Methyl Acrylate [44] (pp. 177 and 233)... 

Other unsaturated substrates arylated by various diaryl iodonium salts included butenone, acrylic acid, methyl acrylate and acrylonitrile [46]. Allyl alcohols with diaryliodonium bromides and palladium catalysis were arylated with concomitant oxidation for example, from oc-methylallyl alcohol, aldehydes of the general formula ArCH2CH(Me)CHO were formed [47]. Copper acetylide [48] and phenyl-acetylene [49] were also arylated, with palladium catalysis. 

Waterlot, C., D. Couturier, and B. Rigo. 2000. Montmorillonite-palladium-copper catalyzed cross-coupling of methyl acrylate with aryl amines. Tetrahedron Lett. 41 317-319. 

H° =NeTf2N Me N "Bu Pd(OAc)2 Et3N 100 °C. Phosphine-free arylation of methyl acrylate with aryliodides presence of catalytic amounts of various halide ions were found to accelerate the reaction excellent recycling of the catalyst demonstrated product extracted with cyclohexane. [21] [79]... 

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. ... 

An example of conjugate free-radical addition to methyl acrylate mediated by a copper Lewis acid has been reported (Sch. 30) [65]. In this example the Lewis acid 127 activates the substrate for conjugate addition by the aryl radical which is followed by an enantioselective chlorine atom-transfer step. Chemical and optical yield for the transformation are both low. 

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