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Corresponding Amines (corresponding + amine)
Selected AbstractsChiral Concave Imidazolinium Salts as Precursors to Chiral Concave N -Heterocyclic Carbenes,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 22 2007Ole Winkelmann Abstract Imidazolinium moieties have been incorporated into bimacrocycles to generate precursors for concave N -heterocyclic carbenes (NHCs). By using one symmetrically substituted benzene bridgehead and one naphthalene bridgehead devoid of local C2 -symmetry, axially chiral concave imidazolinium ions have been obtained. Starting from 2,7-dihydroxy-1-nitronaphthalene (7), the phenol groups have been transformed to 4-pentenyl ethers 8, and the nitro group was then reduced to the corresponding amine 9. Next, 9 and a 2,6-bis(alkenyloxy)aniline 10 were connected by an oxalic acid linker. After reduction of the diamide 13 to diamine 14, a bridge was installed with triethyl orthoformate to give a tetraalkenyl-substituted imidazolinium salt 15. Ring-closing metathesis of 15 followed by hydrogenation of the products 16 yielded the bimacrocyclic salts 17 in 9,18,% overall yield (based on 7), giving amounts up to >300 mg. The configurational stability of 17 was investigated by NMR using chiral enantiopure anions TRISPHAT 18 and BINPHAT 19 as stereodynamic probes.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Tripodands with Phenyl and Thiophenyl Rings and Nitrogen Bridgehead Atoms,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 23 2006Martin Baier Abstract The flexible tripodands 7,9 and 15 with phenyl and thiophenyl rings as "legs" and nitrogen as bridgehead atoms have been synthesized by three-component condensation reactions of the corresponding amine with the aryl halide. The more rigid species 10,14 and 17 were built up from the podands 7,9 as well as from their iodine substitution products 33,35 by a sequence of ethynylation and C,C coupling reactions. Podand 16 was prepared from tris-iodide 36 by Sonogashira coupling with phenylacetylene. In the cases of 7, 12, 15,17, 22, 24, 35, 36, and 41 the structural parameters were determined by X-ray studies. With the exception of 7, 12, and 17, all structures show either close intermolecular contacts between heteroatoms (15, 22, 24, 35, and 36), C,H···N hydrogen bonding (41), or are closely packed as a result of ,···, stacking (16). We were able to isolate silver triflate complexes of 9, 10, and 16, and in the case of 9 we obtained crystals suitable for X-ray diffraction studies. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Synthesis of 14C-labeled and tritiated AMPA potentiator LY450108JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 2 2005Boris A. Czeskis Abstract Asymmetric synthesis of AMPA potentiator LY450108-[14C] containing 14C-label attached to the chiral center of the molecule, was accomplished based on Evans' chiral oxazolidinone auxiliary method. Diastereoselective methylation of p -nitrophenylacetic acid derivative was used as a key step. The auxiliary was reductively removed, and the resulting primary alcohol was converted into the corresponding amine. Its sulfonylation, reduction of the aromatic nitro group, and acylation with 3,5-difluorobenzoyl chloride led to the final product. The synthesis of tritiated LY450108 is also detailed. Copyright © 2005 John Wiley & Sons, Ltd. [source] Synthesis of 15N-labelled nornicotine and 15N-labelled nicotineJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 13 2001Giang Vo-Thanh Abstract The synthesis of 15N-labelled nornicotine 2 and 15N-labelled nicotine 1 is described via the reductive aminocyclization of a 1,4-ketoaldehyde with a corresponding amine in the presence of sodium cyanoborohydride. Yields of 30% and 26%, respectively, were obtained from 3-bromopyridine. The 15N-label has been easily introduced from ammonium- 15N-labelled chloride as an inexpensive label source. As far as we are aware, this is the first synthesis of 15N-labelled nicotine. Copyright © 2001 John Wiley & Sons, Ltd. [source] Mono-, Bi-, Tri- and Tetranuclear Palladium(II), Copper(I), and Gold(I) Complexes of Morpholine- and N -Methylpiperazine-Functionalized Cyclodiphosph(III)azans, cis -[(tBuN-,)2(PNC4H8X)2] (X = O, NMe)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 26 2010Maravanji S. Balakrishna Abstract Bis(amido)cyclodiphosphazanes, cis -[(tBuN-,)2(PNC4H8O)2] (2) and cis -[(tBuN-,)2(PNC4H8NMe)2] (3) were synthesized by treating the corresponding amines with cis -[ClP(tBuN-,)2PCl] (1). The stoichiometric reactions of 2 or 3 with elemental sulfur and selenium afforded the bis-chalcogenides, cis -[(tBuN-,)2(P(E)NC4H8X)2] (X = O, E = S; 4, X = NMe, E = S; 5, X = O, E = Se; 6, X = O, E = Se; 7). The reactions of 2 or 3 with [PdCl2(SMe2)2] produced exclusively the mononuclear trans -[PdCl2{(tBuN-,)2(PNC4H8X)2}2] (X = O; 8, X = NMe; 9), whereas the reactions with [Pd(,-Cl)(,3 -C3H5)]2 afforded the bimetallic complexes [{PdCl(,3 -C3H5)}2{(tBuN-,)2(PNC4H8X)2}] (X = O; 10, X = NMe; 11) in good yield. Treatment of 2 or 3 with [AuCl(SMe2)] in 1:1 and 1:2 molar ratios yielded the mono- and binuclear complexes, [{AuCl(tBuN-,)2(PNC4H8O)2}] (X = O; 12, X = NMe; 13), [{AuCl}2{(tBuN-,)2(PNC4H8O)2}] (X = O; 14, X = NMe; 15), respectively. The PdII (8) and AuI (12) complexes were used as metallo-ligands to prepare homo- and heterometallic complexes, trans -[PdCl2{(tBuN-,)2(PNC4H8O)2}2{Pd(,3 -C3H5)Cl}2] (16), trans -[PdCl2{(tBuN-,)2(PNC4H8O)2}2(AuCl)2] (17), and [Cu(CH3CN)(,-Cl)2Cu(CH3CN){(tBuN-,)2(PNC4H8O)2}2(AuI)2](18). The crystal structures of 2, 4, 7,9, 14, 15, and 18 were established by single-crystal X-ray diffraction studies. [source] N -Tetrachlorophthaloyl (TCP) Protection for Solid-Phase Peptide SynthesisEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 17 2004Esther Cros Abstract The N -tetrachlorophthaloyl-(TCP-)amino protecting group has been evaluated for use in solid-phase peptide synthesis. The TCP group was unaffected by exposure to either piperidine or N,N -diisopropylethylamine (DIEA), which suggests compatibility with both Fmoc and Boc solid-phase synthesis protocols. Quantitative TCP removal was achieved by treatment with hydrazine/DMF (3:17) at 35 °C for 30 min or with ethylenediamine/DMF (1:200) at 50 °C for 30 min. Several C-terminal peptide amides were synthesized successfully by following protocols that use hydrazine/DMF (3:17) at 40 °C for 1 h for repetitive deprotection. Treatment of TCP-amines with methylamine or with diamines did not give the corresponding amines (deprotected), but rather the appropriate N,N, -disubstituted tetrachlorophthalamides, which corresponds to a single ring-opening step. This observation was harnessed to prepare linear and macrocyclic peptide,arene hybrids based on the mild reaction of the parent TCP compound with 1,3-diaminopropane/DMF (1:49) at 25 °C for 5 min. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Highly Chemo- and Regioselective Reduction of Aromatic Nitro Compounds Catalyzed by Recyclable Copper(II) as well as Cobalt(II) PhthalocyaninesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010Upendra Sharma Abstract Copper/cobalt phthalocyanines were established for the first time as catalysts for the very efficient chemo- and regioselective reduction of aromatic nitro compounds to generate the corresponding amines. The selective reduction of nitro compounds was observed in the presence of a large range of functional groups such as aldehyde, keto, acid, amide, ester, halogen, lactone, nitrile and heterocyclic functional groups. Furthermore, the present method was found to be highly regioselective towards the reduction of aromatic dinitro compounds in a short time with high yields. In most of the cases the conversion and selectivity were >99% as monitored by GC-MS. The reduction mechanism was elucidated by UV-vis and electrospray ionization quadrupole time-of-flight tandem mass spectrometry. [source] Copper-in-Charcoal-Catalyzed, Tandem One-Pot Diazo Transfer-Click ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009Ching-Tien Lee Abstract Copper-in-charcoal (Cu/C) is an effective heterogeneous catalyst for tandem diazo transfer/click reactions. In the presence of Cu/C, various azides can be generated in situ from the corresponding amines, and subsequently undergo [3+2],cycloaddition with terminal alkynes to afford triazoles in good yields. The catalyst is also easily recycled. [source] Liquid-Liquid-Liquid Phase Transfer Catalysis: A Novel and Green Concept for Selective Reduction of Substituted NitroaromaticsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2005Ganapati Abstract The selective reduction of nitroaromatics to the corresponding amines is an important transformation since many aromatic amines exhibit biological activities and find a multitude of industrial applications, being intermediates for the synthesis of dyes, pharmaceuticals and agrochemicals. A variety of nitroaromatics dissolved in organic solvents was reduced by using aqueous sodium sulfide, and tetrabutylammonium bromide (TBAB) as the phase transfer catalyst by choosing appropriate concentrations which resulted in three immiscible liquid phases. Compared to L-L PTC, the L-L-L PTC offers much higher rates of reaction, better selectivities and repeated use of catalyst. The selectivities for the desired products were 100%. [source] | ||||||||||