Results 131 to 140 of about 54,273 (155)

Diazoketones as precursors in β-lactam synthesis. New insights into the mechanism of the photochemically induced Staudinger reaction

Journal of the Chemical Society, Perkin Transactions 1, 2001
Diazoketones 1–3, derived from suitably protected amino acids (Ala, Val and Tle), have been photochemically rearranged in the presence of imines leading exclusively to trans-arranged 4-aryl- and cinnamoyl-substituted β-lactams 17–33 with up to 84% yield. Selectivities were dependent on the steric demand of the amino acid side-chain ranging from 65 ∶ 35
Michael R. Linder, Wolfgang U. Frey, Joachim Podlech   +2 more
openaire   +1 more source

Synthesis of 4-aminoguaiazulene and its δ-lactam derivatives

Tetrahedron Letters, 2011
Abstract A method for nitrogen insertion into guaiazulene hydrocarbons is developed. A one-pot reaction of 7-isopropyl-1-methylazulene-4-carboxylic acid, diphenylphosphoryl azide, and an alcohol (MeOH, tBuOH or BnOH) affords the corresponding carbamates.
Kiriazis Alexandros, Aumuller Ingo, Yli-Kauhaluoma Jari   +2 more
openaire   +1 more source

Synthesis of spiro-annelated γ-lactams by isocyanide-based multicomponent reactions involving hem-disubstituted bifunctional reagents

Proceedings of The 17th International Electronic Conference on Synthetic Organic Chemistry, 2013
The new bifunctional hem-disubstituted alicyclic compounds IIIa-e and IVa-e were synthesized in several steps involving alkylation with allyl bromide following oxidative cleavage. Hem-disubstitues oxo-esters IIIa-e were introduced into azido-Ugi reaction followed by one-pot intramolucular bond formation to afford 3-(tetrazol-5-yl)-2-azaspiro[4.n]alkan ...
Vasiliy Stolyarenko, Ananatoliy Evdokimov, Vladimir Shishkin   +2 more
openaire   +1 more source

Bacterial production of carbapenems and clavams: evolution of β-lactam antibiotic pathways

Trends in Microbiology, 1998
Research into two of the four classes of naturally produced beta-lactams--the clavams and carbapenems--has started to throw light upon their biochemical pathways and underlying genetics. Interesting similarities between these two classes, from their joint discovery to an apparently common beta-lactam ring-forming enzyme, are now being revealed.
S J, McGowan, B W, Bycroft, G P, Salmond
openaire   +2 more sources

Clinical Evaluation of In Vitro Tests in Diagnosis of Immediate Allergic Reactions to β-Lactam Antibiotics

Allergy & Clinical Immunology International - Journal of the World Allergy Organization, 2002
María Sanz, P.M. Gamboa, A.L. de Weck
openaire   +1 more source

Discontinuing β-lactam treatment after 3 days for patients with community-acquired pneumonia in non-critical care wards (PTC): a double-blind, randomised, placebo-controlled, non-inferiority trial

Lancet, The, 2021
Aurélien Dinh, Jacques Ropers, Clara Duran   +2 more
exaly  

Structural basis of broad-spectrum β-lactam resistance in Staphylococcus aureus

Nature, 2023
J Andrew N Alexander, Joshua Jenkins, Mark Paetzel   +2 more
exaly  

Mn(III)-Promoted Sulfur-Directed 4-Exo-Trig Radical Cyclization of Enamides to β-Lactams

Tetrahedron, 1998
openaire   +1 more source

Stereoselective construction of β-, γ- and δ-lactam rings via enzymatic C–H amidation

Nature Catalysis, 2023
David A Vargas, Arkajyoti Sengupta, Kendall Houk   +2 more
exaly  

New β-Lactam–β-Lactamase Inhibitor Combinations

Clinical Microbiology Reviews, 2020
Dafna Yahav, Vincent H Tam, Leonard Leibovici   +2 more
exaly