共查询到20条相似文献,搜索用时 46 毫秒
1.
Christina Jäger Dr. Martin Nieger Prof. Kari Rissanen Prof. Dr. Jan Deska 《European journal of organic chemistry》2023,26(39):e202300288
The assembly of enzymatic cascades and multi-step reaction sequences represents an attractive alternative to traditional synthetic-organic approaches. The biocatalytic reaction mediators offer not only mild conditions and permit the use of environmentally benign reagents, but the high compatibility of different enzymes promises more streamlined reaction setups. In this study, a triple-enzymatic strategy was developed that enables the direct conversion of γ,δ-unsaturated esters to N-hydroxy-γ-lactam building blocks. Hereby, a lipase-catalyzed hydroxylaminolysis generates hydroxamic acid intermediates that are subsequently aerobically activated by horseradish peroxidase and glucose oxidase to cyclize in an intramolecular nitroso ene reaction. Utilizing the hydroxylaminolysis/ene-cyclization sequence for the preparation of an aza-spirocyclic lactam, the multi-enzymatic methodology was successfully employed in the synthesis of key intermediates en route to alkaloids of the Cephalotaxus family. 相似文献
2.
Sabine Ruf Gerd Neudert Susanne Gürtler Renate Grünert Patrick J. Bednarski Hans-Hartwig Otto 《Monatshefte für Chemie / Chemical Monthly》2008,139(7):847-857
A number of 1,4-diaryl-3-methylene substituted β-lactams, the addition products obtained from their reactions with N-, S-,
and C-nucleophiles, and diverse related compounds were prepared, and a selection of 43 compounds was screened in preliminary
tests as anti-tumor compounds by using 4 or 5 human cancer cell lines of diverse origins. Twelve compounds were highly active
against all cell lines, 6 showed low activity, 12 no activity, and 13 exhibited a selective activity against a human small
cell lung carcinoma cell line.
Correspondence: Hans-Hartwig Otto, Department of Pharmaceutical/Medicinal Chemistry (PMC), Institute of Pharmacy, Ernst-Moritz-Arndt-University,
17487 Greifswald, Germany. 相似文献
3.
Sabine Ruf Gerd Neudert Susanne Gürtler Renate Grünert Patrick J. Bednarski Hans-Hartwig Otto 《Monatshefte für Chemie / Chemical Monthly》2008,43(5):847-857
A number of 1,4-diaryl-3-methylene substituted β-lactams, the addition products obtained from their reactions with N-, S-,
and C-nucleophiles, and diverse related compounds were prepared, and a selection of 43 compounds was screened in preliminary
tests as anti-tumor compounds by using 4 or 5 human cancer cell lines of diverse origins. Twelve compounds were highly active
against all cell lines, 6 showed low activity, 12 no activity, and 13 exhibited a selective activity against a human small
cell lung carcinoma cell line. 相似文献
4.
《Tetrahedron letters》1987,28(25):2883-2886
γ-Lactam analogues of monocyclic β-lactam antibiotics, the oxamazins, have been prepared from N-protected γ-nitro-α-amino acid esters. Unlike the oxamazins, these higher homologues are devoid of biological activity. 相似文献
5.
Stefanie Beck Dr. Michael Feller Laura Spies Kai J. Dietrich Christoph Jessen Dr. Karin Stierstorfer Prof. Dr. Andreas J. Kornath 《ChemistryOpen》2021,10(1):8-15
Abstract : γ-Butyrolactone and γ-butyrolactam were reacted in the superacidic systems XF/MF5 (X=H, D; M=As, Sb). Salts of the monoprotonated species of γ-butyrolactone were obtained in terms of [(CH2)3OCOH]+[AsF6]−, [(CH2)3OCOH]+[SbF6]− and [(CH2)3OCOD]+[AsF6]− and the analogous lactam salts in terms of [(CH2)3NHCOH]+[AsF6]−, [(CH2)3NHCOH]+[SbF6]− and [(CH2)3NDCOD]+[AsF6]−. The salts were characterized by low temperature Raman and infrared spectroscopy and for both protonated hexafluoridoarsenates, [(CH2)3OCOH]+[AsF6]− and [(CH2)3NHCOH]+[AsF6]−, single-crystal X-ray structure analyses were conducted. In addition to the experimental results, quantum chemical calculations were performed on the B3LYP/aug-cc-pVTZ level of theory. As in both crystal structures C⋅⋅⋅F contacts were observed, the nature of these contacts is discussed with Mapped Electrostatic Potential as a rate of strength. 相似文献
6.
7.
Camille Banoun Killian Henault Dr. Emmanuel Magnier Dr. Guillaume Dagousset 《European journal of organic chemistry》2024,27(16):e202400119
We describe herein the direct electrophilic γ-trifluoromethylthiolation and γ-methylthiolation of enals, via the in situ formation of the corresponding silyl dienol ether. This one-pot process is carried out under simple and mild reaction conditions and is compatible with a variety of functional groups. 相似文献
8.
V. V. Sharutin A. P. Pakusina I. V. Egorova O. K. Sharutina G. K. Fukin 《Russian Journal of Coordination Chemistry》2008,34(4):259-263
Tetraphenylantimony γ-phenylacetylacetonate (I) and tetraphenylstibium γ-thiobutylacetylacetonate (II) are synthesized by the reaction of pentaphenylantimony with γ-phenylacetylacetone or γ-thiobutylacetylacetone in toluene. According to the X-ray diffraction data, the antimony atoms in complexes I and II have a distorted octahedral coordination. In complex I, the Sb-C bond lengths are 2.155(2)–2.170(1) Å, and the Sb-O(1), Sb-O(2) and O(1)-C(2), O(2)-C(4) in the heterocycle are 2.215(1), 2.227(1) and 1.282(2), 1.277(2) Å, respectively. In complex II, the bond lengths are the following: Sb-C 2.147(3)–2.161(3), Sb-O(1, 2) 2.281(2), 2.215(2), and O-C 1.267(3)–1.278(3) Å. 相似文献
9.
GuoJuanLIANG JinZhongZHANG AnQiCHEN 《中国化学快报》2005,16(5):601-603
A novel macrolactonization method was developed using a chiral β-lactam as the template. This novel method features that the macrocyclization is simultaneously achieved while a TBS protected hydroxy group is deprotected. 相似文献
10.
V. A. Tartakovskii I. A. Savost'yanova B. G. Gribov S. S. Novikov 《Russian Chemical Bulletin》1963,12(7):1204-1205
Summary The denitration of -mercurinitro compounds has been studied and the corresponding organomercury dinitro derivatives have been obtained. 相似文献
11.
Becauseoftheimportanceofbenzothiazepinederivatives,whichexhibitversatilebiologicalactivities.thechemistryofbenzothiazepinehasarousedinterestforalongtime'-'.Inourpreviouspapers.wehavereportedthesynthesisandelucidationofthestereostructureoftwokindsofl,5-benzothiazepine-6-lactams'-'.InordertoelucidatetheinfluenceofthesizeofthesubstituentatC-2ontheconfigurationof0-lactammoietyandfurtherstudythestereochemistryofthecycloadditionreaction.wepreparedaseriesofnewfi-lactamderivativesofI.5-benzothiazepine… 相似文献
12.
Rephosgenation of N-carboxyanhydrides of γ-benzyl and y-methyl L-glutamates, vs multiple recrystallizations, is a very efficient method for obtaining highly purified N-carboxyanhydrides, from which very high MW (0.98-1.5 × 106 Daltons) polymers can be derived. 相似文献
13.
Es wird die analog der des Dictamnins durchgeführte Synthese des -Fagarins beschrieben. 相似文献
14.
Maria Hoffmann Czeslaw Wasielewski 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):69-73
Abstract γ-Glutamylphosphonodidepsipeptides 3a-f were obtained by condensation of α-t-butyl or α-benzyl ester of optically active N-benzyloxycarbonyl-glutamic acid with di-p-nitrobenzyl 1-hydroxymethanephosphonate, (+) dibenzyl 1-hydroxy-2-methylpropanephosphonate and (-) dibenzyl 1-hydroxy-3 methylbutanephosphonate. Dicyclohexylcarbodiimide in the presence of 4-(N,N-dimethylamino)- pyridine and 1-hydroxybenzotriazole in methylene chloride was used as a condensing agent for compounds 3a-c. Compounds 3d-f were obtained by means of the dicyclohexylcarbodiimide method in the presence of 4-(N, N-dimethylamino)pyridine in carbon tetrachloride. Protecting groups were removed by conventional methods. 相似文献
15.
《Tetrahedron letters》1987,28(33):3861-3864
Porcine pancreatic lipase in anhydrous organic solvents catalyses the lactonisation of a number of esters of γ-hydroxyacids in nearly quantitative yields. This enzymatic process was used for the highly stereoselective synthesis of (S)-(−)-γ-methylbutyrolactone, (R)-(+)-γ-methylbutyrolactone and of optically active γ-phenylbutyrolactone. 相似文献
16.
Michael addition of lithium enolates of γ-butyrolactone 1 and α-methyl-γ-butyrolactone 1′ to (E)-1-nitropropene 2, (E)-β-nitrostyrene 3 and (E)-2-nitro-1-phenylpropene 4 is described. Reactions of the lithium enolate of 1′ with 2 and 4 occurred with high diasteroselectivity (80 and 92% d.e., respectively). Reactions of the zinc enolate of 1′ with two β-nitroenamines and two methylthio-substituted 1-amino-2-nitro-1,3-dienes were also examined. Catalytic reduction of the nitroalkylated and nitroalkenylated products allowed the achievement of functionalized γ-lactams and/or cyclic hydroxamic acids. 相似文献
17.
Lisheng Xu Guizhen Gao Cao Wengen Jigui Xu Liang Zhao Hongwei Shi Xingtao Zhang 《Applied biochemistry and biotechnology》2014,173(4):851-856
A new method for the synthesis of γ-glutamylmethylamide is presented. Glutamic acid γ-methyl ester was used as substrate for γ-glutamylmethylamide synthesis catalyzed by Escherichia coli with γ-glutamyltranspeptidase activity. Reaction conditions were optimized by using 300 mM glutamic acid γ-methyl ester and 3,000 mM methylamine at pH 10 and 40 °C. Bioconversion rate of γ-glutamylmethylamide reached 87 % after 10 h. γ-Glutamyltranspeptidase was reversibly inhibited only when glutamic acid γ-methyl ester was above 300 mM. 相似文献
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19.
Dr. Md. Emdadul Hoque Prof. Dr. Jin-Quan Yu 《Angewandte Chemie (International ed. in English)》2023,62(49):e202312331
γ-methylene C(sp3)−H functionalization of linear free carboxylic acids remains a significant challenge. Here in we report a Pd(II)-catalyzed tandem γ-arylation and γ-lactonization of aliphatic acids enabled by a L,X-type CarboxPyridone ligand. A wide range of γ-arylated γ-lactones are synthesized in a single step from aliphatic acids in moderate to good yield. Arylated lactones can readily be converted into disubstituted tetrahydrofurans, a prominent scaffold amongst bioactive molecules. 相似文献
20.
Prof. Dr. K. C. Nicolaou 《Angewandte Chemie (International ed. in English)》1993,32(10):1377-1385
The first total synthesis of calicheamicin γ was achieved approximately a year ago. In this article, the author presents a personal account of the events, in chronological order, that led to this success story in total synthesis. 相似文献