Chiral multifunctional thiourea-phosphine catalyzed asymmetric [3 + 2] annulation of Morita–Baylis–Hillman carbonates with maleimides

• Hong-Ping Deng,
• De Wang,
• Yin Wei and
• Min Shi

Beilstein J. Org. Chem. 2012, 8, 1098–1104, doi:10.3762/bjoc.8.121

• of Chemistry & Molecular Engineering, East China University of Science and Technology, and 130 MeiLong Road, Shanghai 200237, People’s Republic of China 10.3762/bjoc.8.121 Abstract We have developed a multifunctional thiourea-phosphine catalyzed asymmetric [3 + 2] annulation of Morita–Baylis–Hillman

• previous literature. Keywords: asymmetric [3 + 2] annulation; maleimides; Morita–Baylis–Hillman carbonates; multifunctional thiourea-phosphine; organocatalysis; Introduction Highly functionalized cyclopentene derivatives are important subunits in a variety of biologically active molecules and have

• effective catalysts in the [3 + 2] annulation of MBH carbonates with isatylidene malononitriles to give the desired products in high yields with high enantioselectivities [50]. Furthermore, our group recently also synthesized a series of L-phenylalanine-derived multifunctional thiourea-phosphine catalysts

Liquid-crystalline nanoparticles: Hybrid design and mesophase structures

• Gareth L. Nealon,
• Romain Greget,
• Cristina Dominguez,
• Zsuzsanna T. Nagy,
• Daniel Guillon,
• Jean-Louis Gallani and
• Bertrand Donnio

Beilstein J. Org. Chem. 2012, 8, 349–370, doi:10.3762/bjoc.8.39

Synthetic approaches to multifunctional indenes

• Neus Mesquida,
• Sara López-Pérez,
• Immaculada Dinarès and
• Ermitas Alcalde

Beilstein J. Org. Chem. 2011, 7, 1739–1744, doi:10.3762/bjoc.7.204

• multifunctional indenes with at least two different functional groups has not yet been extensively explored. Among the plausible synthetic routes to 3,5-disubstituted indenes bearing two different functional groups, such as the [3-(aminoethyl)inden-5-yl)]amines, a reasonable pathway involves the (5-nitro-3

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

• of bacterial cell membranes can be tuned, e.g., by the introduction of methyl branches or olefinic double bonds [1]. The biosynthesis of FAs is a repetitive chain elongation process catalysed in animals and fungi by multifunctional megasynthases, and in plants or bacteria by a set of discrete enzymes

A rapid and efficient synthetic route to terminal arylacetylenes by tetrabutylammonium hydroxide- and methanol-catalyzed cleavage of 4-aryl-2-methyl-3-butyn-2-ols

• Jie Li and
• Pengcheng Huang

Beilstein J. Org. Chem. 2011, 7, 426–431, doi:10.3762/bjoc.7.55

• required [22][23][24][25]. For example, multifunctional arylacetylenes 2i and 2k were prepared in 85% and 83% yields in 5 min (Table 3, entries 10 and 11), whereas they were obtained in only 38% and 11% yields in 8 h, respectively, when sodium was used in refluxing toluene (Supporting Information File 1

Tribenzotriquinacenes bearing three peripheral or bridgehead urea groups stretched into the 3-D space

• Jörg Tellenbröker and
• Dietmar Kuck

Beilstein J. Org. Chem. 2011, 7, 329–337, doi:10.3762/bjoc.7.43

• [1][2][3][4][7], the attachment of multifunctional groupings at the convex surface of the TBTQ skeleton has been only scarcely examined [4]. Therefore, we subjected the previously described bridgehead triaminotribenzotriquinacene 12 [4] to the reaction with phenylisocyanate in analogy to the

Hybrid biofunctional nanostructures as stimuli-responsive catalytic systems

• Gernot U. Marten,
• Thorsten Gelbrich and
• Annette M. Schmidt

Beilstein J. Org. Chem. 2010, 6, 922–931, doi:10.3762/bjoc.6.98

• of the superparamagnetic cores in combination with the thermoresponse of the shell. These multifunctional hybrid particles are formed by surface initiated copolymerization of oligo(ethylene glycol) methyl ether methacrylates (labeled as MEMA (M), MEEMA (M’) and OEGMA (O)) with N-succinimidyl

• . The principle described here is applicable to the modification of other biologically or catalytically relevant groups, and will therefore open new ways for the design of multifunctional hybrid nanostructures with different property portfolios. Experimental Materials: Ammonium hydroxide aqueous

• enzymatic digestion of BAPNA catalyzed by magnetically labeled trypsin (). Proposed mechanism of catalytic activity after heating magnetic biocatalyst particles above Tc. Physical and chemical composition of investigated multifunctional core–shell nanoparticles. Acknowledgements Thanks to Prof. T. J. J

Synthesis and crystal structures of multifunctional tosylates as basis for star-shaped poly(2-ethyl-2-oxazoline)s

• Richard Hoogenboom,
• Martin W. M. Fijten,
• Guido Kickelbick and
• Ulrich S. Schubert

Beilstein J. Org. Chem. 2010, 6, 773–783, doi:10.3762/bjoc.6.96

• of well-defined polymer architectures is of major importance for the development of complex functional materials. In this contribution, we discuss the synthesis of a range of multifunctional star-shaped tosylates as potential initiators for the living cationic ring-opening polymerization (CROP) of 2

• hydrophobic; and from hard materials, with a high glass transition temperature via crystalline and chiral polymers [7], to soft materials, with a very low glass transition temperature [8][9]. The synthesis of star-shaped poly(2-oxazoline)s has been reported using a range of multifunctional electrophilic

• -pEtOx (top). b) SEC traces of TetraTos-B and star-PEtOx (in CHCl3:NEt3:2-PrOH; UV-detector at 500 nm). SEC spectrum obtained for star-pEtOx utilizing a photodiode-array detector (eluent: DMF containing 5 mM NH4PF6). General reaction scheme for the preparation of multi-tosylates from multifunctional

Poly(glycolide) multi-arm star polymers: Improved solubility via limited arm length

• Florian K. Wolf,
• Anna M. Fischer and
• Holger Frey

Beilstein J. Org. Chem. 2010, 6, No. 67, doi:10.3762/bjoc.6.67

• which significantly exceed the molecular weight of processable oligomeric linear PGA (<1000 g/mol). This was achieved by the use of a multifunctional hyperbranched polyglycerol (PG) macroinitiator and the tin(II)-2-ethylhexanoate catalyzed ring-opening polymerization of glycolide in the melt. With this

• architectures exhibit significantly altered physical properties [14][15]. This is often considered the primary motivation for the choice of this interesting polymer architecture [16]. A suitable multifunctional core molecule is required to prepare multi-arm star polymers with core–shell characteristics. Apart

• ][24][25][26] has proven to be a versatile and highly potent multifunctional core molecule [27][28][29]. Derivatization and functionalization of the peripheral hydroxy groups of this polyether-polyol have afforded a number of carrier systems [30][31][32][33][34], matching the concept outlined above. In

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

• ]. Rotello and Thayumanavan have described amphiphilic polymer scaffolds, which nonspecifically bound to chymotrypsin, inhibited its peptidase activity and modulated substrate specificity; very high ionic strengths again released the protein from the polymer [6][7]. Protein recognition by multifunctional

New amphiphilic glycopolymers by click functionalization of random copolymers – application to the colloidal stabilisation of polymer nanoparticles and their interaction with concanavalin A lectin

• Otman Otman,
• Paul Boullanger,
• Eric Drockenmuller and
• Thierry Hamaide

Beilstein J. Org. Chem. 2010, 6, No. 58, doi:10.3762/bjoc.6.58

• media. This approach can be easily extended to multifunctional polymer nanoparticles containing encapsulated drugs inside their core. Experimental The syntheses of 8-chloro-3,6-dioxaoctyl 2,3,4,6-tetra-O-acetyl-α-D-mannopyranoside (2) and 8-azido-3,6-dioxaoctyl 2,3,4,6-tetra-O-acetyl-α-D-mannopyranoside

Synthesis, characterization and photoinduced curing of polysulfones with (meth)acrylate functionalities

• Cemil Dizman,
• Sahin Ates,
• Lokman Torun and
• Yusuf Yagci

Beilstein J. Org. Chem. 2010, 6, No. 56, doi:10.3762/bjoc.6.56

• in detail and covered by several review articles [13][14][15]. Photopolymerization is a frequently used process for the conversion of the multifunctional monomers into insoluble networks which are effective in various industrial fields such as, films, inks, coatings; photoresists, etc. [14]. The

• range capable of inducing rapid polymerization to form insoluble networks [16]. Because of their high reactivity leading to fast polymerization [17], multifunctional (meth)acrylates are the most commonly used monomers for many applications [18][19][20][21][22]. The activity of the (meth)acrylates

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

1-(4-Alkyloxybenzyl)-3-methyl-1H-imidazol-3-ium organic backbone: A versatile smectogenic moiety

• William Dobbs,
• Laurent Douce and
• Benoît Heinrich

Beilstein J. Org. Chem. 2009, 5, No. 62, doi:10.3762/bjoc.5.62

• can impart selectivity in reactions by organising reactants, as scaffolds for the synthesis of nanostructured particles [12][13][14], in dye-sensitized solar cells [15][16] or also in bio-related science [17][18]. In conclusion, this combination represents a fascinating class of new multifunctional

Functional properties of metallomesogens modulated by molecular and supramolecular exotic arrangements

• Alessandra Crispini,
• Mauro Ghedini and
• Daniela Pucci

Beilstein J. Org. Chem. 2009, 5, No. 54, doi:10.3762/bjoc.5.54

• single molecule to supramolecular network, confirming that metal coordination provides a helpful tool for obtaining multifunctional soft materials. Keywords: coordination complexes; functionality; liquid crystals; metallomesogens; Introduction Recent interest in designing novel soft and functional

• the metal ion and the counter-ion in ionic systems, has been followed. In this paper selected examples of recently synthesised multifunctional metallomesogens are highlighted, all obtained from classical and unusual nitrogen ligands and different metal centres from across the periodic table, going

• multifunctional soft materials, with higher performance than classical liquid crystals. Our interest in the synthesis of metallomesogens and their wide use in the field of material science, coupled with the fact that transition metal complexes have potential antitumor activity, led us to believe that a great

Ru-catalyzed dehydrogenative coupling of carboxylic acids and silanes - a new method for the preparation of silyl ester

• Guo-Bin Liu and
• Hong-Yun Zhao

Beilstein J. Org. Chem. 2008, 4, No. 27, doi:10.3762/bjoc.4.27

• ester)s were found to be an ideal family of degradable polymers [1]. Also, multifunctional silyl esters have been found to be ideal cross-linking agents since they require only mild reaction conditions, especially for silicone elastomers. The demand for degradable poly(silyl ester)s has been increasing

Electronic differentiation competes with transition state sensitivity in palladium- catalyzed allylic substitutions

• Dominik A. Lange and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2007, 3, No. 36, doi:10.1186/1860-5397-3-36

• of substrate and catalyst structures. "Side arm guidance" of nucleophiles with multifunctional phosphinoferrocenes [14][15][16][17][18] or "chiral pockets" in C2-symmetric diphosphanes based on 2-(diphenyl-phosphino)benzoic acid amides [19][20][21][22] were applied especially successfully. Chiral P,N

A convenient synthesis of γ-functionalized cyclopentenones

• Nour Lahmar,
• Taïcir Ben Ayed,
• Moncef Bellassoued and
• Hassen Amri

Beilstein J. Org. Chem. 2005, 1, No. 11, doi:10.1186/1860-5397-1-11

• previously reported, the 1,4-addition of primary nitroalkanes [7][8][9][10][11][12] to functionalized α,β-unsaturated ketones was considered as an appropriate method to prepare multifunctional nitroketonic compounds. These intermediates are important in organic synthesis because the nitro group can be