Organotellurium-mediated living radical polymerization under photoirradiation by a low-intensity light-emitting diode

• Yasuyuki Nakamura and
• Shigeru Yamago

Beilstein J. Org. Chem. 2013, 9, 1607–1612, doi:10.3762/bjoc.9.183

• , and easy availability of the low-cost light source. Structurally well-defined poly(methyl methacrylate), poly(methyl acrylate), and polystyrene, with narrow molecular weight distributions, were synthesized under LED irradiation with or without a neutral density filter. Keywords: free radical; light

• methacrylate (MMA) in the presence of ditelluride, but other typical conjugated monomers, namely, methyl acrylate and styrene, were also evaluated. TERP of these monomers proceeded efficiently in a controlled manner by adjusting the light intensity using ND filters. The results clearly demonstrate the

• as the use of a 10% transmittance ND filter, resulted in improved MWDs (Table 1, runs 12 and 13). The use of the LED was also found to be effective for the efficient and controlled polymerization of other monomers (Table 2). For example, TERP of methyl acrylate (100 equiv) without ditelluride reached

Diastereoselective synthesis of nitroso acetals from (S,E)-γ-aminated nitroalkenes via multicomponent [4 + 2]/[3 + 2] cycloadditions promoted by LiCl or LiClO₄

• Leandro Lara de Carvalho,
• Robert Alan Burrow and
• Vera Lúcia Patrocinio Pereira

Beilstein J. Org. Chem. 2013, 9, 838–845, doi:10.3762/bjoc.9.96

• system, the reactivity of 5a,b with EVE and methyl acrylate (MA) as a dipolarophile was evaluated in the absence of a promoter. In all experiments conducted, the cycloadducts were obtained in 18–70% yield with total chemo- and regioselectivity including good levels of diastereoselectivity (Table 1). The

• reason ethanol was used as the solvent. The confirmation of the stereostructures of (+/−)-8d,d’ was accomplished by comparison with NMR spectroscopic data available in the literature [9]. Based on these successes, 5a was reacted with EVE and methyl acrylate in LPTW or LCEW solutions (Table 2, entries 3

• besides conjugate addition [19] make them useful chiral building blocks for diastereoselective synthesis. Experimental General EtOH, MeOH, 2-propanol, toluene, LiClO4, LiCl, methyl vinyl ketone, ethyl vinyl ether, methyl acrylate and acrylonitrile were purchased from Aldrich, Acros or Merck and were used

Reactions of nitroxides XIII: Synthesis of the Morita–Baylis–Hillman adducts bearing a nitroxyl moiety using 4-acryloyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl as a starting compound, and DABCO and quinuclidine as catalysts

• Jerzy Zakrzewski

Beilstein J. Org. Chem. 2012, 8, 1515–1522, doi:10.3762/bjoc.8.171

• consistent with the spectra of the typical series of the MBH adducts of common aldehydes and methyl acrylate, presented in [32]. Synthesized compounds 5a–o showed a weak antifungal activity. No insecticidal, acaricidal and herbicidal activity were shown. Conclusion In conclusion, it has been demonstrated

Combined bead polymerization and Cinchona organocatalyst immobilization by thiol–ene addition

• Kim A. Fredriksen,
• Tor E. Kristensen and
• Tore Hansen

Beilstein J. Org. Chem. 2012, 8, 1126–1133, doi:10.3762/bjoc.8.125

• . Consequently, we do not believe this to be an intrinsic property of our thiol–ene polymer beads, connected to the effect of free thiol groups. In addition, capping free thiol groups on beforehand by treatment with excess methyl acrylate did not affect the performance in this transformation. Catalyst 12 was

Carbohydrate-auxiliary assisted preparation of enantiopure 1,2-oxazine derivatives and aminopolyols

• Marcin Jasiński,
• Dieter Lentz and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2012, 8, 662–674, doi:10.3762/bjoc.8.74

• case, led to the formation of methyl acrylate and imine J. This imine underwent subsequent cyclisation to zwitterion K and two proton shifts, probably via 3-exomethylene compound L, finally led to pyrrole 5. This mechanism is certainly speculative but offers a possibility to explain the formation of

Facile isomerization of silyl enol ethers catalyzed by triflic imide and its application to one-pot isomerization–(2 + 2) cycloaddition

• Kazato Inanaga,
• Yu Ogawa,
• Yuuki Nagamoto,
• Akihiro Daigaku,
• Hidetoshi Tokuyama,
• Yoshiji Takemoto and
• Kiyosei Takasu

Beilstein J. Org. Chem. 2012, 8, 658–661, doi:10.3762/bjoc.8.73

• conditions (−10 °C), followed by the addition of methyl acrylate (5) at −78 °C, 6-methylbicyclo[4.2.0]octane 6 and its diastereomer were obtained in 86% and 6%, respectively (Scheme 2a). No formation of their regioisomers was observed. The obtained compound 6 is identical to the product in the reaction of 2a

Branching out at C-2 of septanosides. Synthesis of 2-deoxy-2-C-alkyl/aryl septanosides from a bromo-oxepine

• Supriya Dey and
• Narayanaswamy Jayaraman

Beilstein J. Org. Chem. 2012, 8, 522–527, doi:10.3762/bjoc.8.59

• , Heck, Suzuki and Sonogashira coupling reactions. Heck coupling reactions [24][25] were undertaken first. Thus, the reaction of bromo-oxepine 2 with methyl acrylate was performed, in the presence of Pd(OAc)2 (10 mol %) and Cs2CO3 in 1,4-dioxane, at 98 °C (Scheme 1), to afford diene 3, in 70% yield. The

• (t-Bu), 23.3 (-CH2CH2CO2t-Bu); HRMS–ESI (m/z): [M + Na]+ calcd for 357.1525; found, 357.1526. Synthetic route to transform oxyglycal I to a septanoside V. Reaction conditions: (i) NaOMe, PhMe, reflux, 8 h; (ii) methyl acrylate (for 3); tert-butyl acrylate (for 4); H2C=CHCOO(CH2)5OCOCH=CH2 (for 5; 2

Novel fatty acid methyl esters from the actinomycete Micromonospora aurantiaca

• Jeroen S. Dickschat,
• Hilke Bruns and
• Ramona Riclea

Beilstein J. Org. Chem. 2011, 7, 1697–1712, doi:10.3762/bjoc.7.200

• − 57]+ ion, which is typical for anteiso-FAMEs. The synthesis of methyl 8-methyldecanoate (95) as a reference compound was started from 1-bromo-2-methylbutane (117b, Scheme 3). Copper-catalysed 1,4-addition of the respective Grignard reagent to methyl acrylate in the presence of trimethylchlorosilane

• , dimethyl sulfide, and 4-dimethylaminopyridine gave methyl 5-methylheptanoate (118b). A sequence of LiAlH4 reduction to the alcohol 119b, conversion into the bromide 120b, and Cu-mediated 1,4-addition of the Grignard reagent to methyl acrylate furnished the desired FAME 95. Its mass spectrum and retention

• -methylpentan-1-ol (119c), by similar methods as described above (Scheme 3). The alcohol 119c was transformed into the bromide 120c. The copper-catalysed Michael addition of the respective Grignard reagent to methyl acrylate yielded methyl 6-methyloctanoate (121c), which was α-methylated to 122c. Reduction with

Michael-type addition of azoles of broad-scale acidity to methyl acrylate

• Sławomir Boncel,
• Kinga Saletra,
• Barbara Hefczyc and
• Krzysztof Z. Walczak

Beilstein J. Org. Chem. 2011, 7, 173–178, doi:10.3762/bjoc.7.24

• 4-nitropyrazole, 3,5-dimethyl-4-nitropyrazole, 4(5)-nitroimidazole, 4,5-diphenylimidazole, 4,5-dicyanoimidazole, 2-methyl-4(5)-nitroimidazole, 5(4)-bromo-2-methyl-4(5)-nitroimidazole and 3-nitro-1,2,4-triazole to methyl acrylate as an acceptor was carried out. The optimisation process involved the

• , no corresponding regioisomers were obtained. Keywords: imidazole derivatives; methyl acrylate; Michael-type addition; pyrazole derivatives; 1,2,4-triazole derivatives; Introduction Derivatives of azoles are important biologically active compounds. Many, especially those containing imidazole

• ≤ 6.05), to methyl acrylate under optimised conditions (temperature, type of base and donor/base/acceptor ratio) as a regioselective, efficient and useful reaction for the formation of adducts that can be utilised in the synthesis of more complex systems including intermediates for the pharmaceutical

The cross-metathesis of methyl oleate with cis-2-butene-1,4-diyl diacetate and the influence of protecting groups

• Arno Behr and
• Jessica Pérez Gomes

Beilstein J. Org. Chem. 2011, 7, 1–8, doi:10.3762/bjoc.7.1

• -metathesis reactions of these raw materials with different cross-metathesis reaction partners (allyl alcohol [15][16], allyl chloride [16], acrylonitrile [17], fumaronitrile [18], acrolein [19], methyl acrylate [20] and diethyl maleate [21]) yielding α,ω-difunctional substrates have been investigated. In

The allylic chalcogen effect in olefin metathesis

• Yuya A. Lin and
• Benjamin G. Davis

Beilstein J. Org. Chem. 2010, 6, 1219–1228, doi:10.3762/bjoc.6.140

• methyl acrylate with very high yield [25]. Remarkably, none of the possible RCM products of the diene were detected. This observed chemoselectivity was ascribed to hydrogen-bonding of the allylic hydroxy to the chloride ligand of the catalyst resulting in an intermediate alkylidene 17 which has a

The catalytic performance of Ru–NHC alkylidene complexes: PCy₃ versus pyridine as the dissociating ligand

• Stefan Krehl,
• Diana Geißler,
• Sylvia Hauke,
• Oliver Kunz,
• Lucia Staude and
• Bernd Schmidt

Beilstein J. Org. Chem. 2010, 6, 1188–1198, doi:10.3762/bjoc.6.136

• ]. Therefore, 8 can be considered as a rather challenging substrate. As partners in the cross metathesis reactions, three acrylates 9a–c were chosen. In addition, homodimerization of 8 to diol 11 was also investigated (Scheme 4). The results are summarized in Table 4. With methyl acrylate 9a in dichloromethane

• mg, 0.5 mmol) and methyl acrylate (9a) following the general procedure. Yield of rac-10a using catalyst D: 141 mg (0.42 mmol, 84%). Yield of rac-10a using catalyst E: 139 mg (0.41 mmol, 83%). Yield of rac-10a using catalyst H: 145 mg (0.43 mmol, 86%). 1H NMR (300 MHz, CDCl3) δ 7.37–7.25 (5 H), 6.73

New library of aminosulfonyl-tagged Hoveyda–Grubbs type complexes: Synthesis, kinetic studies and activity in olefin metathesis transformations

• Etienne Borré,
• Frederic Caijo,
• Christophe Crévisy and
• Marc Mauduit

Beilstein J. Org. Chem. 2010, 6, 1159–1166, doi:10.3762/bjoc.6.132

• hour. In order to investigate potential substrate dependency, the activity of the five SIMes-catalysts 4a–e was evaluated in three different cross-metathesis (CM) reactions involving methyl acrylate, methyl vinyl ketone (MVK) and acrylonitrile as electro-deficient alkenes and the two electron-rich

• olefins S1 and S2 (Table 1). In the reaction of methyl acrylate and S1, complexes 4c and 4d proved to be the most efficient catalysts (entries 1–5) while no clear-cut difference in reactivity was observed when MVK and S2 were used (entries 6–10). The CM of S1 and acrylonitrile, which is known to be a

Halide exchanged Hoveyda-type complexes in olefin metathesis

• Julia Wappel,
• César A. Urbina-Blanco,
• Mudassar Abbas,
• Jörg H. Albering,
• Robert Saf,
• Steven P. Nolan and
• Christian Slugovc

Beilstein J. Org. Chem. 2010, 6, 1091–1098, doi:10.3762/bjoc.6.125

• satisfying results. Even the formation of tetra-substituted olefin bonds (Table 3, Entry 2 and 4) was feasible, although yields fell short in comparison to those obtained with catalyst 1. In cross metathesis, 3 was not particularly active in coupling terminal mono-substituted olefins with methyl acrylate and

Synthesis of a novel analogue of DPP-4 inhibitor Alogliptin: Introduction of a spirocyclic moiety on the piperidine ring

• Arumugam Kodimuthali,
• Padala Lakshmi Prasunamba and
• Manojit Pal

Beilstein J. Org. Chem. 2010, 6, No. 71, doi:10.3762/bjoc.6.71

• afforded the corresponding amine 2 (step ii, Scheme 1) which on Michael addition to methyl acrylate followed by N-protection furnished the diester 4 (steps iii and iv, Scheme 1). The N-protection step was necessary to avoid the undesirable participation of the NH group in subsequent steps. A facile base

Symmetrical and unsymmetrical α,ω-nucleobase amide-conjugated systems

• Sławomir Boncel,
• Maciej Mączka,
• Krzysztof K. K. Koziol,
• Radosław Motyka and
• Krzysztof Z. Walczak

Beilstein J. Org. Chem. 2010, 6, No. 34, doi:10.3762/bjoc.6.34

• particularly effective condensing agent. The subunits containing carboxylic groups were obtained by acidic hydrolysis of N-1 Michael adducts of uracils or N-9 Michael adducts of 6-chloropurine with methyl acrylate. The amines used were aliphatic/aromatic diamines, adenine, 5-substituted 1-(ω-aminoalkyl)uracils

• groups were obtained by acidic hydrolysis of N-1 Michael adducts of uracils or N-9 Michael adducts of 6-chloropurine with methyl acrylate (Scheme 1A) [1]. Uracil derivatives were obtained via the fully regioselective one-step procedure as previously reported [11][12]. To construct systems containing

• modified purinic nucleobase, we synthesised the N-9 adduct (1ea) of 6-chloropurine with methyl acrylate in 90% yield using Hünig’s base (diisopropylethylamine) as a deprotonating agent (Scheme 1B) (see Supporting Information File 1). X-ray analysis confirmed the structure of this regioisomer (Figure 2) [13

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

Radical cascades using enantioenriched 7-azabenzonorbornenes and their applications in synthesis

• David M. Hodgson and
• Leonard H. Winning

Beilstein J. Org. Chem. 2008, 4, No. 38, doi:10.3762/bjoc.4.38

• , resulting in electrophile trapping rather than reduction. Encouraged by the above initial result, a number of other electrophiles were considered for the tandem deoxygenation–rearrangement–trapping reaction (Figure 2). Acrylate esters proved effective electrophiles: methyl acrylate and tert-butyl acrylate

• account for the modest isolated yields of the trapped azacycles (Scheme 5). Further electrophile trapping experiments were undertaken with dimethyl xanthate 23: methyl acrylate and phenyl vinyl sulfone gave the corresponding indenes 30 and 31, which could both be isolated, albeit in modest yields. Having

• sodium periodate as the stoichiometric oxidant and esterification using CH2N2 gave diester 35 (49%, 37% using Me3SiCHN2). Attempts to improve the procedure further by the use of alternative solvents proved unsatisfactory. Azacycle (+)-10, the product of deoxygenation-rearrangement-trapping with methyl

N-1 regioselective Michael- type addition of 5-substituted uracils to (2-hydroxyethyl) acrylate

• Sławomir Boncel,
• Dominika Osyda and
• Krzysztof Z. Walczak

Beilstein J. Org. Chem. 2007, 3, No. 40, doi:10.1186/1860-5397-3-40

• ] Mitsunobu reaction;[8] or reactions that operate through ANRORC-mechanisms that require the presence of strongly electron-withdrawing groups.[9] Recently, we have described an N1- and N3-regioselective Michael-type addition of 5-substituted uracil derivatives to methyl acrylate and acrylonitrile.[10

Asymmetric aza-Diels- Alder reaction of Danishefsky's diene with imines in a chiral reaction medium

• Bruce Pégot,
• Olivier Nguyen Van Buu,
• Didier Gori and
• Giang Vo-Thanh

Beilstein J. Org. Chem. 2006, 2, No. 18, doi:10.1186/1860-5397-2-18

• related Baylis-Hillman reaction between p-nitrobenzaldehyde and methyl acrylate using the above chiral IL.[25] A slight increase in de (not optimized value) was detected when employing p-methoxyphenyl (Table 3, entry 2, R = p-MeOC6H4). ILs are highly recyclable and do not lose any of their properties even