Phenyl acrylates

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. 

Dupont et al. were able to obtain up to 80 % ee in the conversion of 2-phenyl-acrylic acid into (S)-2-phenylpropionic acid with the chiral [RuCl2(S)-BINAP]2NEt3 complex as catalyst in [BMIM][Bp4] melts (Scheme 5.2-9) [54]. 

B. Addition of Sodium Cyanide to Ethyl ct-Cyano-fi-phenyl-acrylate —Twenty grams of cyanophenylacrylic aster is treated with 40 cc. of 50 per cent alcohol and 10 g. of finely pow-... 

The condensation of arylsulfonyl acetonitriles 369a-c with 22a proceeds via addition of the in-situ formed anion 370 to the arylsulfonyl acetonitriles 369 to afford the dimers 371, in 69-94% yield, and hexamethyldisiloxane 7 [136]. Furthermore, y9-dicarbonyl compounds such as ethyl acetoacetate 372 a or ethyl benzoyl-acetate 372b are O-silylated by 22 a or 22 c to rather stable alkyl 3-O-trimethylsilyl-oxycrotonoate 373a and alkyl 3-0-trimethylsilyloxy-3-phenyl acrylate 373b [130]. Aliphatic nitro compounds such as nitromethane are O-trimethylsilylated and further transformed into oligomers [132] (cf Section 7.6) and are thus unsuitable reactants for silylation-C-substitutions (Scheme 4.50). 

In 2000, Morken et al. reported the first examples of catalytic asymmetric reductive aldol reactions [21]. Using Rh(BINAP) (5mol%) as catalyst and Et2MeSiH as reductant, the syn-selective (1.7 1) coupling of benzalde-hyde and methyl acrylate produced the diastereomers 35-syn and 35-anti in 91% ee and 88% ee, respectively. Using phenyl acrylate as the nucleophilic partner, a favorable yield of 72% was obtained for the aldol product 36 (Scheme 12). Several aldehydes were examined, which exhibit higher levels of syn-selectivity. Expanding the scope of substrates and acrylates under... 

Preliminary results from a study of catalytic activation of the heterocoupling between arylhalides and alkenes using pony-tail-functionalized dendrimer-encapsulated Pd nanoparticles have shown promise. For example, the classic Pd-catalyzed Heck coupling between arylhalides and methacrylate yields predominately (> 97%) the trans-cinnimaldehyde product [176]. On the other hand, the C02-soluble dendrimer nanocomposite exclusively catalyzes the production of the highly unfavored 2-phenyl-acrylic acid methyl ester isomer at 5000 psi and 75 °C (Fig. 27] [177]. 

BINAP core-functionalized dendrimers were synthesized by Fan et al. (36), via condensation of Frechet s polybenzyl ether dendritic wedges to 5,5 -diamino-BINAP (26—28). The various generations of BINAP core-functionalized dendrimers were tested in the ruthenium-catalyzed asymmetric hydrogenation of 2-[p-(2-methyl-propyl)phenyl]acrylic acid in the presence of 80 bar H2 pressure and in a 1 1 (v/v) methanol/toluene mixture. As later generations of the in situ prepared cymeneruthe-nium chloride dendritic catalysts were used, higher activities were observed (TOF values were 6.5, 8.3, and 214 h respectively). Relative to those of the BINAP... 

This method of quantum yields calculation was verified in more detail in studying the photorearrangement of 4-methylphenyl benzoate (60) (in ethanol with 253.7 nm).71 The quantum yield of ester decrease, Additional examples are calculations of the photorearrangements of poly-4-benzoyloxystyrene (in dioxane with 253.7 nm) (cpA = 0.082, methyl-phenyl acrylate ([Pg.138]

Another reaction which occurs readily in solid polymers is the Fries reaction which can be observed in phenyl esters, particularly in phenyl acrylate and phenyl methacrylate polymers. The course of the reaction can be followed very... 

A considerable amount of attention has also been paid to the photo-Fries rearrangement of polymer pendant groups. For example, the rearrangement of poly (phenyl acrylate) (10,11) in solution or in the solid-state, is usually incomplete and results in the formation of both the ortho and the para-hydroxyphenone rearranged products in amounts which vary with the conditions of the photolysis. A concurrent side-reaction, which we term the Fries degradation, also results in the liberation of small amounts of phenol (Scheme 2). Similar results have been obtained with poly (phenyl methacrylate) and other substituted aryl acrylates (4,9,12). 

Nitro-phenyl)-acrylic acid ethyl ester... 

The hyperbaric 4 + 2-cycloaddition of 1,2,4-trioxegenated 1,3-dienes with dieno-philes, A-phenylmaleimide, and methyl and phenyl acrylates produced the expected endo-cycloadducts with excellent stereo- and regio-control.113 The high-pressure (g) Diels-Alder reactions of 3-substituted coumarins with methylbuta-1,3-dienes in water formed tetrahydro-6H-benzo[c]chromen-6-ones in high yields (85-95%).114... 

Related ligands for catalysis, namely BINAP ligands substituted with Frechet dendrons (5, Fig. 6.34) were prepared by Chan et al. [51]. They form rutheniu-m(II) complexes in situ, whose activity in the stereoselective hydrogenation of 2-[p-(2-methylpropyl)phenyl]acrylic acid was investigated. 

Ethyl acetoacetate, 31, 1, 57 32, 76, 84 Ethyl a-acetyl-/3-(2,3-dimethoxy-phenyl)acrylate, 31, 5(5, 58 Ethyl a-acetyl-/S-(3,4-dimethoxy-phenyl)acrylate, 31, 58 Ethyl q -acetyl-/3-(2,3-dimethoxy-phenyl)propionate, 31, 56 Ethyl a-acetyl-/3-(3,4-dimethoxy-phenyl)propionate, 31, 58 Ethylamine, 2-chloro-N,N-di-... 

Scheme 5.25 The 119a-mediated aza-MBH reaction of tosyl aryl aldimines with phenyl acrylate and acrolein. EWG = electron-withdrawing group.

Willson TM, Henke BR, Momtahen TM, Charifson PS, Batchelor KW, Lubahn DB, Moore LB, Oliver BB, Sauls FIR, Triantafillou JA, Wolfe SG, Baer PG (1994) 3-[4-(l,2-Diphenylbut-l-enyl)phenyl]acrylic acid a non-steroidal estrogen with functional selectivity for bone over uterus in rats. J Med Chem 37 1550-1552... 

Preparation of cis/trans methyl-l-amino-2-cyclohexylethyl-l-methyl-(3-phenyl acrylic acid)phosphinate (generic procedure)... 

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