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Showing 1 to 20 of 91 for “"Lactams"”.
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Kinetic Resolution of N-Acyl-b-Lactams, b-Lactams, and N-Acyl-Thiolactams using Amidine-Based Catalysts
… mostly Type I: KR of various alcohols and lactams: and thiolactams) via asymmetric acylation) and Type III: enantioselective alcoholysis of α-substituted acids and azlactones) processes.</p><p>As a contribution and an extension to enantioselective, catalytic, nucleophilic acyl substitution …
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NMR studies of dimeric and polymeric lactams.
The aim of this work was to study the solution conformation of dimeric and polymeric 1actams. In a first part of this work, the synthesis of bicyc1odi1actams as precursors of the polymers was explored. A new preparation for the 2, 5-diazabicyc1o [2,2,2] octa-3, 6-dione was developed. The dimers and …
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Formation of β-lactams and related compounds. II. Alkyl phosphates and thiophosphates
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemistry, 1955
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A general catalytic β-C–H carbonylation of aliphatic amines to β-lactams
Carbonyl compounds are of central importance to organic chemistry and their reactions have been described as the ‘backbone of organic synthesis’. Over recent decades, palladium-catalysed C–H carbonylation reactions have emerged as a powerful means of introducing carbonyl motifs to organic …
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Selective Synthesis of Trans-fused Lactam-Lactones by Vicinal Difunctionalization of Readily Affordable Allylic Lactams
… plethora of medicinal properties. Specifically, lactams and lactones are the respective luminaries of the antibiotic and flavor worlds. However, the synthesis of fused lactams-lactones, especially those bearing <em>trans</em>-fusion, is challenging from the standpoints of chemoselectivity, …
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Synthetic and chromatographic study of the spiro-lactams and spiro-lactones based on a 9',10'-dihydro-(9,10)-ethanoanthracene Diels-Alder adduct. Application of flash vacuum thermolysis towards synthesis of exo-methylene lactones and lactams
Synthesis of a variety of spiro-lactams and spiro-lactones which are based on a 9$\sp\prime$,10$\sp\prime$-dihydro- (9,10) -ethanoanthracene Diels-Alder adduct has been performed. Control of relative stereochemistry at the C2 and C2, C3 carbons on the lactone ring during synthesis of the …
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Nucleophilic Addition to Azoalkenes; Diastereoselective Synthesis of β-Hydroxy Ketones and β,γ-Fused γ-Lactams
The α-alkylation of ketones and their derivatives by the addition of their corresponding enolates to alkyl halides is a fundamental synthetic transformation, but its utility is limited because the key bond-forming step proceeds in a bimolecular nucleophilic substitution fashion. Here in the first …
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Synthesis of 4-(trifluoromethyl)azetidin-2-one building blocks and their transformation into novel CF3-substituted amines and heterocyclic systems
… light of the versatile synthetic potential of β-lactams on the one hand and the beneficial impact of fluorine on biological properties on the other hand, β-lactams bearing a trifluoromethyl group comprise interesting entities for the construction of novel targets with promising bioactivities. In …
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Chromatographic Separation of Enantiomers of Some Physiologically Active Types of Compounds on Chiral Stationary Phases (Benzodiazepinones, Beta-Lactams, Beta-Aminoacids)
… and enantiomers of aryl substituted (beta)-lactams can be separated directly on amino acid derived chiral stationary phases, whereas (beta)-amino acid enantiomers can be separated, after conversion to the dinitrobenzamide esters, on amide or N-aryl amino acid derived chiral stationary …
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QSAR study of immunotoxicity in antibiotics.
… and yet safe. A major drawback to the ~-lactams is the degree of immunologically adverse reactions they induce. It was the aim of this study to develop both mechanistic and immunological methods to enable the prediction of a B-lactam's potential to induce an allergic response and to …
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Enantioenriched Homoaldol Products, Beta-Substituted Ketones, Isoxazolines, and Beta-Lactams Through Elaboration of Allylamine Asymmetric Homoenolate Equivalents: Synthesis and Elucidation of Reaction Pathways
A stereocontrolled intramolecular nitrone/olefin dipolar cycloaddition reaction of enantioenriched enals provides cyclopentyl isoxazoline products in 64--81% yields and with diastereomeric ratios of 78:22 to 84:16. An isoxazoline was converted into an enantiomerically pure beta-lactam via a …
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Structural characterization of superbug proteins involved in regulating beta-lactam resistance
The widespread use of β-lactams has undermined their effectiveness as chemotherapeutic agents by fueling the evolution and dissemination of multiple resistance mechanisms, including: (1) production of hydrolytic β-lactamase enzymes that inactivate β-lactams, (2) expression of PBPs with …
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INHIBITOR RESISTANCE MECHANISMS AND INHIBITOR DESIGN IN ¿¿-LACTAMASES
… at the speed required by bacterial evolution. ¿¿-Lactams are commonly prescribed antibiotics and ¿¿-lactamases are major contributors to antibiotic resistance. While the fields of ¿¿-lactams, ¿¿-lactamases and ¿¿-lactamase inhibition are well studied and understood; there exist several knowledge …
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C-H Activation of Functional Materials
… aliphatic secondary amines to form secondary lactams. The diastereoselectivity of the reaction was found to be significantly influenced by the choice of reaction conditions. Under optimised conditions, a wide range of lactams were delivered in high yields and good d.r., with many different …
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