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911.
SA Hudson KJ McLean S Surade YQ Yang D Leys A Ciulli AW Munro C Abell 《Angewandte Chemie (International ed. in English)》2012,51(37):9311-9316
Pieces of the puzzle: The first fragment-based approach was used to target cytochrome?P450 enzymes (CYPs) for drug development. The experiments provide new insights into the binding site of the essential Mycobacterium tuberculosis CYP121 enzyme, and resulted in a promising novel lead compound based on fragment merging. 相似文献
912.
Śledź P Lang S Stubbs CJ Abell C 《Angewandte Chemie (International ed. in English)》2012,51(31):7680-7683
Probing the pocket: A high-throughput fluorescence-based thermal shift (FTS) assay utilized different forms of a protein (in gray) to establish the binding mode of a ligand (see picture). The assay serves in the rapid evaluation of structure-activity binding-mode relationships for a series of ligands of Plk1, an important target of anticancer therapy. 相似文献
913.
914.
Hutchby M Houlden CE Haddow MF Tyler SN Lloyd-Jones GC Booker-Milburn KI 《Angewandte Chemie (International ed. in English)》2012,51(2):548-551
Stick or twist: By introducing steric hindrance at the nitrogen atom, stable linear amides bearing an electron-withdrawing α-substituent (Z = Ar, PhSO(2), P(O)(OR)(2), CN, or CO(2)R) can be induced to undergo solvolysis and substitution reactions through an elimination-addition mechanism (see picture). Key to this process is a low barrier to rotation around the amide bond and the α-substituent?Z. 相似文献
915.
Complementary α-alkylation approaches for a sterically hindered spiro[pyrazolopyranpiperidine]ketone
Chris Limberakis Jianke Li Gayatri Balan David A. Griffith Daniel W. Kung Colin Rose Derek Vrieze 《Tetrahedron letters》2012,53(20):2543-2547
Complementary α-alkylation methods are used to derivatize a sterically hindered spiro[pyrazolopyranpiperidine]ketone. More specifically, enolate alkylations in the presence of DMPU and aldol condensations are employed to deliver these compounds. 相似文献
916.
Bo Qu Nizar Haddad Sonia Rodriguez Heewon Lee Shengli Ma Xingzhong Zeng Diana C. Reeves Kanwar P.S. Sidhu Jon C. Lorenz Nelu Grinberg Carl A. Busacca Dhileepkumar Krishnamurthy Chris H. Senanayake 《Tetrahedron letters》2012,53(15):1982-1986
A novel trans-diastereoselective reductive amination of 4-substituted cyclohexanones is described using 9-BBN as reducing agent in the presence of FeCl3. The method permits efficient synthesis of structurally diverse 4-trans-alkoxycyclohexylamines. 相似文献
917.
Chris Walpole Ziping Liu Ernest E. Lee Hua Yang Fei Zhou Nicole Mackintosh Magnus Sjogren David Taylor Jinyu Shen Robert A. Batey 《Tetrahedron letters》2012,53(24):2942-2947
A diastereoselective synthesis of fluoropiperidine quinazoline spirocycles has been developed through a silyl triflate mediated intermolecular coupling of difluorobenzamidine and racemic N-protected 3-fluoropiperidine dimethyl ketals or piperidones. Combination of the silyl reagents together with Lewis acids (such as BF3·OEt2, ZnCl2, InCl3, etc.) accelerated the coupling reaction to afford the desired fluorospirocycles in good yields (40–83%) and high diastereoselectivity. A ratio of the two diastereoisomers of up to 10:1 in favor of the desired isomer can be achieved. 相似文献
918.
The reaction of terbium and europium salts with the lacunary polyxometalate (POM) [As(2)W(19)O(67)(H(2)O)](14-) and 2-picolinic acid (picH) affords the ternary lanthanoid-organic-polyoxometalate (Ln-org-POM) complexes [Tb(2)(pic)(H(2)O)(2)(B-β-AsW(8)O(30))(2)(WO(2)(pic))(3)](10-) (1), [Tb(8)(pic)(6)(H(2)O)(22)(B-β-AsW(8)O(30))(4)(WO(2)(pic))(6)](12-) (2), and [Eu(8)(pic)(6)(H(2)O)(22)(B-β-AsW(8)O(30))(4)(WO(2)(pic))(6)](12-) (3). A detailed synthetic investigation has established the conditions required to isolate pure bulk samples of the three complexes as the mixed salts H(0.5)K(8.5)Na[1]·30H(2)O, K(4)Li(4)H(4)[2]·58H(2)O, and Eu(1.66)K(7)[3]·54H(2)O, each of which has been characterized by single crystal X-ray diffraction. Complexes 2 and 3 are isostructural and can be considered to be composed of two molecules of 1 linked through an inversion center with four additional picolinate-chelated lanthanoid centers. When irradiated with a laboratory UV lamp at room temperature, compounds K(4)Li(4)H(4)[2]·58H(2)O and Eu(1.66)K(7)[3]·54H(2)O visibly luminesce green and red, respectively, while compound H(0.5)K(8.5)Na[1]·30H(2)O is not luminescent. A variable temperature photophysical investigation of the three compounds has revealed that both the organic picolinate ligands and the inorganic POM ligands sensitize the lanthanoid(III) luminescence, following excitation with UV light. However, considerably different temperature dependencies are observed for Tb(III) versus Eu(III) through the two distinct sensitization pathways. 相似文献
919.
Meyer FM Collins JC Borin B Bradow J Liras S Limberakis C Mathiowetz AM Philippe L Price D Song K James K 《The Journal of organic chemistry》2012,77(7):3099-3114
A general method for constraining peptide conformations via linkage of aromatic sidechains has been developed. Macrocyclization of suitably functionalized tri-, tetra- and pentapeptides via Suzuki-Miyaura cross-coupling has been used to generate side chain to side chain, biaryl-bridged 14- to 21-membered macrocyclic peptides. Biaryl bridges possessing three different configurations, meta-meta, meta-ortho, and ortho-meta, were systematically explored through regiochemical variation of the aryl halide and aryl boronate coupling partners, allowing fine-tuning of the resultant macrocycle conformation. Suzuki-Miyaura macrocyclizations were successfully achieved both in solution and on solid phase for all three sizes of peptide. This approach constitutes a means of constraining peptide conformation via direct carbogenic fusion of side chains of naturally occurring amino acids such as phenylalanine and tyrosine, and so is complementary to strategies involving non-natural, for example, hydrocarbon, bridges. 相似文献
920.
Herrmann C Salas PF Patrick BO de Kock C Smith PJ Adam MJ Orvig C 《Dalton transactions (Cambridge, England : 2003)》2012,41(21):6431-6442
This work presents a new family of organometallic antimalarial compounds consisting of ferrocene bearing a chloroquine-derived moiety as well as a 1,2;3,5-diisopropylidene glucofuranose moiety at a cyclopentadienyl scaffold in a 1,2-substitution pattern. The synthetic route proceeds via a stereoselective functionalization of ferrocene carboxaldehyde to the 1,2-disubstituted conjugates. After complete characterization of these new, trifunctional conjugates, they were examined for their cytotoxicity in two cancerous cell lines (MDA-MB-435S and Caco2) and one non-cancerous cell line (MCF-10A), showing that increased cytotoxicity can be observed for the chloroquine ferrocenyl conjugates compared to their carbohydrate-substituted precursors. The antiplasmodial activity of the conjugates in a chloroquine-sensitive strain of Plasmodium falciparum (D10) and a chloroquine-resistant strain (Dd2) was determined. Monosubstituted conjugates 13, 14 and 15 exhibit decreasing activity with increasing alkyl chain length between the ferrocene and quinoline moiety, bifunctional conjugates 16, 17, 18 show constant activity, performing better than chloroquine in the Dd2 strain. 相似文献