نتایج جستجو برای: lactams
تعداد نتایج: 5234 فیلتر نتایج به سال:
Fifteen novel β-lactams bearing the N-ethyl tert-butyl carbamate group 5a-o and fifteen N-(2-aminoethyl) β-lactams 6a-o were synthesized by the ketene-imine [2+2] cycloaddition reaction (Staudinger ). The cycloaddition reaction was found to be totally diastereoselective leading exclusively to the formation of the cis-β-lactam derivatives. These newly synthesized β-lactams were evaluated for the...
we describe here a suitable approach for the synthesis of n-unsubstituted monocyclic b-lactams under mild reaction conditions by the annelation of imines with substituted acetylchlorides. in this method the reaily available phtalimidoacetyl chloride were allowed to react with - dibenzylideneiminotoluene (hydrobenzamide) in the presence of an equimolar amount of triethylamine in refluxing toluen...
Fifteen novel β-lactams bearing the N-ethyl tert-butyl carbamate group 5a-o and fifteen N-(2-aminoethyl) β-lactams 6a-o were synthesized by the ketene-imine [2+2] cycloaddition reaction (Staudinger ). The cycloaddition reaction was found to be totally diastereoselective leading exclusively to the formation of the cis-β-lactam derivatives. These newly synthesized β-lactams were evaluated for the...
The synthesis of some 13-lactams is described. 'The electronic activation of monocyclic B-lactams provided by a quinonemethine function was found to instabilize the 13-lactam ring toward nucleophilic: attack by water
the synthesis of some 13-lactams is described. 'the electronic activation of monocyclic b-lactams provided by a quinonemethine function was found to instabilize the 13-lactam ring toward nucleophilic: attack by water
Some new b-lactams bearing biologically important morpholine ring have been synthesized by acylation of amino b-lactams in the presence of morpholine-4-carbonyl chloride. These novel β-lactams were prepared under mild reaction conditions without any solvent in short reaction times. Their biological activities have been examined against microbial agents such as Staphylococcus aureus (S. aureus),...
Some new b-lactams bearing biologically important morpholine ring have been synthesized by acylation of amino b-lactams in the presence of morpholine-4-carbonyl chloride. These novel β-lactams were prepared under mild reaction conditions without any solvent in short reaction times. Their biological activities have been examined against microbial agents such as Staphylococcus aureus (S. aureus),...
A new strategy for catalytic enantioselective C-acylation to generate α-quaternary-substituted lactams is reported. Ni-catalyzed three-component coupling of lactam enolates, benzonitriles, and aryl halides produces β-imino lactams that then afford β-keto lactams by acid hydrolysis. Use of a readily available Mandyphos-type ligand and addition of LiBr enable the construction of quaternary stereo...
Highly enantiomerically enriched γ- and δ-lactams have been prepared by a simple and very efficient procedure that involves the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)iminoesters followed by desulfinylation of the nitrogen atom and spontaneous cyclization to the desired lactams during the basic workup procedure. Five- and six-membered ring lactams bearing aromatic, heteroaro...
β-Lactams are pharmacologically important compounds because of their various biological uses, including antibiotic and so on. β-Lactams were synthesized from benzylidene-inden derivatives and acetoxyacetyl chloride. The inhibitory effect of these compounds was examined for human carbonic anhydrase I and II (hCA I, and II) and acetylcholinesterase (AChE). The results reveal that β-lactams are in...
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