Acrylates tert-butyl

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. 

Scheme 1 Synthetic steps for compounds 1 and 2.1 2-chloroacetic acid, 2 M aq. Na2C03, 80 °C, 20h, yield 51% 11 acetic anhydride, anhydrous sodiiun acetate, 60 °C, 5h, yield 65% 111 sodium sulfite, H2O, 90 °C, 4h, yield 82% IV toluene/piperidines, reflux 4h, yield 61% V tert-butyl acrylate, tri-(0-tolyl)phosphine, Pd(OAc)2, EtsN, DMF, reflux, yield 70-91% VI H2, 10% Pd/C, rt, yield 96-100% Vll TFA, DCM, rt, yield 75-100% Vlll (a) isobutylchloroformate, EtsN, dry DCM, 0°C, (b) R2NH, DCM, rt, 62-70% IX UAIH4, dry THF, yield 24-44% [11]...

General procedure for Heck coupling. A mixture of POPd (16.0 mg, 6 mol%), quinoline derivative (0.56 mmol), tert-butyl acrylate (356 mg, 2.8 mmol), and base (0.61 mmol) was stirred in 5 mL of anhydrous DMF at 135 °C for 24 h. The reaction mixture was allowed to cool to room temperature, quenched with water, and extracted with Et20. The combined organic layers were washed with water, dried over MgS04, and the solvents were removed under vacuum. The crude products were purified by flash chromatography on silica gel. 

ATRP and grafting from methods led to the synthesis of poly(styrene-g-tert-butyl acrylate)-fr-poly(ethylene-co-butylene)-fr-poly(styrene-g-ferf-butyl acrylate) block-graft copolymer [203]. ATRP initiating sites were produced along the PS blocks by chloromethylation as shown in Scheme 112. These sites then served to polymerize the ferf-butyl acrylate. The poly(ferf-butyl acrylate) grafts were hydrolyzed to result in the corresponding poly(acrylic... 

The same authors [38] further refined these catalysts by developing very bulky cyclophane diimine palladium(II) catalysts (Fig. 5), which show greater activity and stability than their acyclic analogs. The incorporation levels of acrylates (methyl and tert-butyl acrylate were exemplified) are unusually high (up to around 25... 

PS—polystyrene, PMMA—poly(methyl methacrylate), PMA—poly(methyl acrylate), PDMAEMA—poly((Nd f-dimethylamino)ethyl methacrylate), PDMA—poly( dimethyl-acrylamide), P(t-BA)—poly(tert-butyl acrylate), PAA—poly(acrylic acid), PPFS—poly (pentafluorostyrene), PHFA—poly(heptadecafluorodecyl acrylate)... 

NBA = /j-butyl acrylate TBA = tert-butyl acrylate EtA = ethyl acrylate CNBr = jo-CN(C6H4)Br N02Br = p N02(C6H4)Br MeOBr = p- CH30(C6H4)Br TBAB = tetrabutylammonium bromide. 

Ic also initiates the living polymerization of tert-butyl acrylate even in the dark Hoso-... 

The dimerization of methyl- isopropyl- and tert butyl-acrylates under the conditions of Equation 1 is less stereoselective (Table 3) 2). In less polar media such as toluene, however, the methylation stereoselectivity is enhanced. 

The asymmetric aziridination of a, P-unsaturated carboxylic acid derivatives is a direct route to optically active aza-cyclic a-amino acids, and this class of chiral aziridines can also be used as chiral building blocks for the preparation of other amino acids, P-lactams, and alkaloids. Prabhakar and coworkers carried out an asymmetric aziridination reaction of tert-butyl acrylate with O-pivaloyl-N-arylhydroxylamine 25 in the presence of cinchonine-derived chiral ammonium salt 2e under phase-transfer conditions, which furnished the corresponding chiral N-arylaziridine 26 with moderate enantioselectivity (Scheme 2.24) [46],... 

The chiral quaternary ammonium salt 47a with a single tartrate moiety and free hydroxyl groups gave disappointing results for the Michael addition of Schiff s base 20 with tert-butyl acrylate in the presence of CsOH base. However, the benzyl-protected catalyst 47b promoted Michael addition, and the adduct (S)-49 was obtained in 57% yield, although the enantioselectivity remained low (Table 7.6, entry 2). The use of catalyst 48a,b with two tartrate moieties afforded the best results at —60 ° C, and Michael adduct (S)-49 was obtained in good enantioselectivity up to 77% ee (entries 4 and 5). 

The use ofTaddol as an asymmetric phase-transfer catalyst has been adopted by other research groups. For example, Jaszay has used Taddol for Michael additions to a-aminophosphonate derivative 20, as shown Scheme 8.10 [22]. A range ofTaddol derivatives was investigated, but the best results were again obtained with the same catalyst employed by Belokon and Kagan. Thus, phosphoglutamic acid derivative 21 was obtained in 95% yield and with 72% ee when tert-butyl acrylate was employed as the Michael acceptor. 

Homopolymer PS and block copolymer poly(tert-butyl acrylate)-b-styrene, prepared by nitroxide-mediated living free-radical polymerization, were utilized for the functionalization of shortened SWCNTs through a radical coupling reaction (Scheme 1.33) [194]. 

Pentadienyl-terminated poly(methyl methacrylate) (PMMA) as well as PSt, 12, have been prepared by radical polymerization via addition-fragmentation chain transfer mechanism, and radically copolymerized with St and MMA, respectively, to give PSt-g-PMMA and PMMA-g-PSt [17, 18]. Metal-free anionic polymerization of tert-butyl acrylate (TBA) initiated with a carbanion from diethyl 2-vinyloxyethylmalonate produced vinyl ether-functionalized PTBA macromonomer, 13 [19]. 

Quinap (95) in a number of mutually unrelated transition-metal-catalyzed asymmetric reactions.50 Thus, 105 added to tert-butyl acrylate 106 using silver acetate and PINAP ligand 96, under the conditions described in Scheme 2.25, to provide the desired product 109 in excellent enantioselectivity and yield (see Scheme 2.6 and Table 2.5). Notably, the reaction required only 3 mol% of catalyst for complete conversion at -40°C within 36 h. 

Najera et al. have shown that Feringa s phosphoramidite ligand 102 is superior to other ligands in the cycloaddition of aryl iminoesters 62 with tert-butyl acrylate (106), /V-methylphthalimide 114, and diisopropyl fumarate (118).57 As shown in Scheme 2.31 and Table 2.9, the products 116 and 117 were formed in excellent yields and exquisite endo selectivity. 

Schemes Poly(tert-butyl acrylate)-Wocfc-poly(2-cinnamoylethyl methacrylate) [173]...

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