Synthesis of tripodal catecholates and their immobilization on zinc oxide nanoparticles

• Franziska Klitsche,
• Julian Ramcke,
• Julia Migenda,
• Andreas Hensel,
• Tobias Vossmeyer,
• Horst Weller,
• Silvia Gross and
• Wolfgang Maison

Beilstein J. Org. Chem. 2015, 11, 678–686, doi:10.3762/bjoc.11.77

• chloride to give acrylamide 4. Treatment of 4 with dimethylamine and excess KOH leads to the nucleophilic addition of the amine and saponification of the methyl esters in one step to give the free acid 5 after acidic work-up. Subsequent coupling of 5 to dopamine acetonide 6 with EDC and HOBt gave the

• an effector was prepared. This triscatecholate might be useful for the construction of diamandoid hydrophobic coatings [44] or for the reversible attachment of cyclodextrins to NPs by the formation of cyclodextrin/adamantane inclusion complexes [45]. Alternatively, acrylamide 4 and bromide 12 [42

Morita–Baylis–Hillman reaction of acrylamide with isatin derivatives

• Radhey M. Singh,
• Kishor Chandra Bharadwaj and
• Dharmendra Kumar Tiwari

Beilstein J. Org. Chem. 2014, 10, 2975–2980, doi:10.3762/bjoc.10.315

• Abstract The Morita–Baylis–Hillman reaction of acrylamide, as an activated alkene, has seen little development due to its low reactivity. We have developed the reaction using isatin derivatives with acrylamide, DABCO as a promoter and phenol as an additive in acetonitrile. The corresponding aza version

• with acrylate and acrylonitrile has also been developed resulting in high product yields. Keywords: acrylamide; isatin; ketimine; Morita–Baylis–Hillman; phenol; Introduction The Morita–Baylis–Hillman (MBH) reaction is an important carbon–carbon bond-forming reaction [1][2][3]. It involves the

• , the acryl system shows differences in reactivity upon slight structural modifications. In such a system, the enone and acrylonitrile are more reactive, while with the acrylate reaction is relatively slow. Furthermore, there is a decrease of reactivity with acrylamide due to the reduced Michael

End group functionalization of poly(ethylene glycol) with phenolphthalein: towards star-shaped polymers based on supramolecular interactions

• Carolin Fleischmann,
• Hendrik Wöhlk and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 2263–2269, doi:10.3762/bjoc.10.235

• phenolphthalein (see Scheme 1). In a first step, the monofunctional phenolphthalein-monomer N-(2-hydroxy-5-(1-(4-hydroxyphenyl)-3-oxo-1,3-dihydroisobenzofuran-1-yl)benzyl)acrylamide (PP-AAm) was synthesized following a protocol we developed in a previous study [46]. Afterwards, the corresponding amine derivative

The regioselective synthesis of spirooxindolo pyrrolidines and pyrrolizidines via three-component reactions of acrylamides and aroylacrylic acids with isatins and α-amino acids

• Tatyana L. Pavlovskaya,
• Fedor G. Yaremenko,
• Victoria V. Lipson,
• Svetlana V. Shishkina,
• Oleg V. Shishkin,
• Vladimir I. Musatov and
• Alexander S. Karpenko

Beilstein J. Org. Chem. 2014, 10, 117–126, doi:10.3762/bjoc.10.8

• azomethine ylide, which regioselectively adds to the C=C bond of acrylamide or aroylacrylic acid. Since the stereochemistry of the cycloadducts 4a and 6a was clarified by a single-crystal X-ray analysis, the structures of the reacting systems – the azomethine ylide and dipolarophiles (acrylamide and

• verified by calculations of vibrational frequencies within the harmonic approximation, using analytical second derivatives at the same level of theory. All stationary points possess zero imaginary frequencies. It was found that the acrylamide conformer I was more stable than conformer II by 1.24 kcal/mol

• the most reactive sites of the reagents. The reaction proceeds regioselectively with the addition of the most nucleophilic methylene group carbon of the azomethine ylide to the most electrophilic sites of the acrylamide and benzoylacrylic acid, which affords only one stereoisomer of cycloadducts 4 and

Polymeric redox-responsive delivery systems bearing ammonium salts cross-linked via disulfides

• Christian Dollendorf,
• Martin Hetzer and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 1652–1662, doi:10.3762/bjoc.9.189

• of DNA encapsulation used in anti-cancer treatment [16][17][18][19][20][21][22][23]. Further examples for polymeric networks based on poly(ethylenimine) (PEI) or poly(diethyl acrylamide) (PDEA) can be found in the literature [24][25][26]. Disulfide bonds are generally stable in human blood

A construction of 4,4-spirocyclic γ-lactams by tandem radical cyclization with carbon monoxide

• Mitsuhiro Ueda,
• Yoshitaka Uenoyama,
• Nozomi Terasoma,
• Shoko Doi,
• Shoji Kobayashi,
• Ilhyong Ryu and
• John A. Murphy

Beilstein J. Org. Chem. 2013, 9, 1340–1345, doi:10.3762/bjoc.9.151

• cyclization due to the longer C–S bonds. We then tried to extend the tandem spirocyclization approach to obtain 4,4-spirocyclic oxindole γ-lactam and tested two substrates, 2-(azidomethyl)-N-benzyl-N-(2-iodophenyl)acrylamide (1f) and the nitrogen-unprotected analogue 1g. The reaction of 1f was smooth to give

• -iodophenyl)acrylamide (1f) (150.0 mg, 0.36 mmol), AIBN (2,2’-azobisisobutyronitrile, 17.7 mg, 0.11 mmol), TTMSS ([tris(trimethylsilyl)silane], 178.3 mg, 0.72 mmol) and THF (17.9 mL; 0.02 M) were placed in a 50 mL stainless steel autoclave. The autoclave was closed, purged three times with CO, pressurized

Homolytic substitution at phosphorus for C–P bond formation in organic synthesis

• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 1269–1277, doi:10.3762/bjoc.9.143

• Me3M–PPh2 (M = Sn, Si) and V-40 (Table 9) [26]. Secondary and tertiary alkyl iodides participate in the addition reaction while primary alkyl iodide results in direct phosphination prior to the expected addition. Not only acrylate ester but also acrylamide, vinyl sulfone, and acrylonitrile are good

Cascade radical reaction of substrates with a carbon–carbon triple bond as a radical acceptor

• Hideto Miyabe,
• Ryuta Asada and
• Yoshiji Takemoto

Beilstein J. Org. Chem. 2013, 9, 1148–1155, doi:10.3762/bjoc.9.128

• transfer conditions by using isopropyl iodide and Et3B. The reaction of hydroxamate ester 5 did not give the desired product probably due to polymerization of 5 through the labile acrylamide moiety. In contrast, the reaction of 6A–C proceeded effectively to give the cyclic products 9Aa–9Ca in good yields

Total synthesis and biological evaluation of fluorinated cryptophycins

• Christine Weiß,
• Tobias Bogner,
• Benedikt Sammet and
• Norbert Sewald

Beilstein J. Org. Chem. 2012, 8, 2060–2066, doi:10.3762/bjoc.8.231

• homoallyl alcohol 16. The magnesium bromide diethyl etherate mediated allylation proceeded under substrate control and with complete diastereoselectivity [23][32]. Cross-metathesis of homoallyl alcohol 16 with the unit B derived acrylamide 17 provided the α,β-unsaturated δ-hydroxy carboxamide 18 (Scheme 2

• ). In order to bring about complete metathesis of 16, the acrylamide 17 had to be employed in 1.2-fold excess, which resulted in a contamination of the cross-metathesis product 18 with minor amounts of the homo-coupling product 23. The latter could not be separated by flash chromatography on this stage

Interaction of cyclodextrins with pyrene-modified polyacrylamide in a mixed solvent of water and dimethyl sulfoxide as studied by steady-state fluorescence

• Akihito Hashidzume,
• Yongtai Zheng and
• Akira Harada

Beilstein J. Org. Chem. 2012, 8, 1312–1317, doi:10.3762/bjoc.8.150

• hydrochloride was purchased from Sigma-Aldrich Co. Ltd. Acryloyl chloride was obtained from Tokyo Chemical Industry Co. Ltd. Triethylamine, acrylamide (AAm), ammonium peroxodisulfate (APS), acetone, methanol, DMSO (spectroscopic grade), NaHCO3, and NaOH were purchased from Nacalai Tesque Inc. N,N

Design of a novel tryptophan-rich membrane-active antimicrobial peptide from the membrane-proximal region of the HIV glycoprotein, gp41

• Evan F. Haney,
• Leonard T. Nguyen,
• David J. Schibli and
• Hans J. Vogel

Beilstein J. Org. Chem. 2012, 8, 1172–1184, doi:10.3762/bjoc.8.130

• particular peptide in aqueous buffer. Therefore, the smaller blue shifts for gp41w can be attributed to the peptide dissociating from the oligomeric form followed by peptide insertion into the bilayer. Acrylamide quenching experiments were performed for the four peptides to examine the accessibility of the

• Trp fluorophores in the various membrane environments. If a Trp side chain inserts into the hydrophobic core of the bilayer, it becomes less accessible to the effects of the soluble acrylamide quencher. The quenching of Trp fluorescence is directly related to the concentration of quencher, so a

• titration with the neutral acrylamide allows for the calculation of the Stern–Volmer constant (Ksv), which quantitatively measures the accessibility of the Trp residues in various lipid environments. The Ksv values for the gp41w peptides are summarized in Figure 3. Consistent with the other fluorescence

Miniemulsion polymerization as a versatile tool for the synthesis of functionalized polymers

• Daniel Crespy and
• Katharina Landfester

Beilstein J. Org. Chem. 2010, 6, 1132–1148, doi:10.3762/bjoc.6.130

• -soluble, surface active, and oil-soluble initiators were employed to initiate the polymerizations as shown in Figure 1. Oil-soluble initiators were found to give a higher yield of copolymers of acrylamide and methyl methacrylate with a low extent of blockiness than with a water-soluble initiator or

• surface active initiator. By contrast, the surface active polyethylene glycol azo-initiator yielded polymers almost free of homopolymers with a low blockiness when acrylamide and styrene were copolymerized. Wu et al. used the same principle but with monomers having the ability to copolymerize alternately

• the encapsulation of hydrophobic substances could be obtained. Capsules could be also obtained when methacrylic acid was used instead of acrylic acid [31]. Wu and Schork investigated the copolymerization between the functional n-methylol acrylamide and vinyl acetate in batch and semi-batch processes

RAFT polymers for protein recognition

• Alan F. Tominey,
• Julia Liese,
• Sun Wei,
• Klaus Kowski,
• Thomas Schrader and
• Arno Kraft

Beilstein J. Org. Chem. 2010, 6, No. 66, doi:10.3762/bjoc.6.66

• from earlier work with linear polymers and microgels [9][15][16]: Sodium methacrylate (2) (S), polymerizable tetrazolate 3 (T) and bisphosphonate 4 (B). These anionic comonomers were directly copolymerized with NIPAM and a hydrophobic acrylamide. The latter carried cyclohexyl (CH), benzyl (BN) or octyl

N-alkyl-N-(phosphonoethyl) substituted (meth)acrylamides – new adhesive monomers for self-etching self-priming one part dental adhesive

• Joachim E. Klee and
• Uwe Lehmann

Beilstein J. Org. Chem. 2009, 5, No. 72, doi:10.3762/bjoc.5.72

• spectroscopy as well as refractive index and viscosity. The phosphonoethyl substituted (meth)acrylamide monomers show improved hydrolytic stability compared to carboxylic esters. The highest stability was found for the phosphonoethyl substituted acrylamide monomers. Acrylamides have a larger polymerization

• -methylacrylamidomethyl)benzylphosphonic acid [2] and a bis(meth)acrylamide comprising one phosphoric acid moiety [3] have been prepared and were investigated for a dental adhesive. Furthermore, (meth)acrylamides with one [4][5][6][7][8] or two [7][8][9] phosphonic acid groups were suggested as hydrolytically stable

• acid ethyl ester with trimethylsilyl bromide (Scheme 1, Table 1). (Meth)acrylamides 3a and 3b were prepared by addition of vinylphosphonic acid ethyl ester to acrylamide and methacrylamide respectively and the same procedure for methanolysis of the phosphonic acid ethyl ester as that described above