33812-91-8Relevant academic research and scientific papers
Tosylimidazole-mediated one-pot synthesis of 2-azetidinones
Zavar, Saleheh,Zarei, Maaroof,Saraei, Mahnaz
, p. 532 - 534 (2016)
Cyclocondensation of Schiff bases and substituted acetic acid with tosylimidazole afforded 2-azetidinones in good to excellent yields. This reaction works reliably well for monocyclic and spirocyclic 2-azetidinones. This reaction is green and efficient an
Pyrolysis of azetidinone derivatives: A versatile route towards electron-rich alkenes, C-1 allylation and/or homologation of aldehydes
Al-Hamdan, Nouf S.,Habib, Osama M.,Ibrahim, Yehia A.,Al-Awadi, Nouria A.,El-Dusouqui, Osman M. E.
, p. 21023 - 21031 (2014/06/09)
Pyrolysis of β-lactams and β-thiolactams led essentially to stereoselective synthesis of the high energy electron-rich Z-alkenes. Extension of this methodology to the pyrolysis of 3-allyloxy derivatives gave a simple direct route to the synthetically important 4-pentenal. These pyrolytic transformations convert aldehydes to aryloxyalkenes (a protected homologation) and 4-pentenal (a C-1 allylation and homologation). The starting 3-aryloxy and 3-allyloxy-β-lactams were synthesized by the standard Staudinger ketene-imine [2 + 2] cycloaddition. The corresponding β-thiolactams have readily been obtained in good yields by thiation of β-lactams with Lawesson's reagent. This journal is the Partner Organisations 2014.
Remarkable ketene substituent dependent effect of photo irradiation on the diastereoselectivity in the Staudinger reaction
Yang, Zhanhui,Xu, Jiaxi
supporting information; experimental part, p. 786 - 789 (2012/03/10)
Controlling diastereoselectivity is a challenging issue in the Staudinger reaction. The influence of ultraviolet irradiation on the stereoselectivity in the Staudinger reaction has been investigated. The results indicate that ultraviolet irradiation is on
Synthesis of 3-alkoxy/aryloxy - Lactams using diazoacetate esters as ketene precursors under photoirradiation
Qi, Hengzhen,Yang, Zhanhui,Xu, Jiaxi
experimental part, p. 723 - 730 (2011/04/24)
3-Alkoxy/aryloxy - lactams are synthesized in satisfactory to good yields from the reaction of imines and alkyl/aryl di-azoacetates under photoirradiation conditions. Typically, trans - lactams are obtained as the major products from linear imines using the current method. By contrast, the corresponding thermal reaction of imines and alkoxy/aryloxyacetyl chlorides, or their equivalents, in the presence of triethylamine affords cis - lactams as the major or exclusive products. The formation of trans - lactams from linear imines is attributed to isomerization of the imines from their trans-isomers into syn-isomers under UV irradiation. The reported method represents a metal-free and neutral approach for the synthesis of 3-alkoxy/aryloxy - lactams. Georg Thieme Verlag Stuttgart New York.
Hypocholesterolemic activity of some novel azetidin-2-ones in diet and diabetes induced hypercholesterolemia in rats
Goel,Thind,Bal,Mahajan,Kulkarni
, p. 369 - 374 (2007/10/03)
Some novel substituted azetidin-2-ones (5-8) were synthesized via {2 + 2} cycloaddition reactions of imines and ketenes and evaluated for their ability to prevent diet and diabetes induced hypercholesterolemia. The test compounds 5a and 7a significantly (p a dose dependent manner. Compound 5a also raised the high density lipoprotein-cholesterol levels in chronic diet models by peanut oil (5.5%), cholesterol (1.5%) and cholic acid (0.5%). In a diabetes induced model of hypercholesterolemia, the test compounds were evaluated for preventing diabetes-induced hypercholesterolemia (protocol 1) as well as for lowering post diabetic hypercholesterolemia (protocol 2). Test compounds 5a-g and 7a-d significantly (p a greater reduction in protocol 1 as compared with protocol 2. Based on SAR studies, the substituents that favor hypocholesterolemic activity around the azetidin-2-one nucleus are discussed and a possible mechanism of action is proposed on the basis of their differential effects in two protocols of diabetes-induced hypercholesterolemia.
Triphosgene: A versatile reagent for the synthesis of azetidin-2-ones
Krishnaswamy,Govande,Gumaste,Bhawal,Deshmukh
, p. 2215 - 2225 (2007/10/03)
An efficient use of triphosgene, as an acid activator, for the synthesis of substituted azetidin-2-ones via ketene-imine cycloaddition reaction using various acids and imines have been described.
Unprecedented stereoselectivity in the Staudinger reaction with polycyclic aromatic imines
Banik,Becker
, p. 6551 - 6554 (2007/10/03)
Cycloaddition of imines derived from polycyclic aromatic amines with acid chloride (or equivalent) in the presence of triethylamine at -78°C to room temperature unexpectedly produced trans-β-lactams. (C) 2000 Elsevier Science Ltd.
Reagents and Synthetic Methods. Part 58. Synthesis of β-Lactams from Acetic Acids and Imines promoted by Vilsmeier Type Reagents
Arrieta, Ana,Lecea, Begona,Palomo, Claudio
, p. 845 - 850 (2007/10/02)
The development of a practical method for the stereospecific preparation of several 3-substituted β-lactams from acetic acids and imines is described.The key step of the method is the activation of the carboxy component by means of Vilsmeier type reagents.The preparation of some N-(2'-hydroxyethyl)-β-lactams and N-(p-dimethyl-t-butylsiloxyphenyl)-β-lactams as intermediates for N-H azetidinones is also reported.For the last compounds the steric bulk of the N-substituent is the key feature for a high cis-β-lactam formation.
Synthesis of β-lactams from acetic acids and imines induced by phenyl dichlorophosphate reagent
Arrieta,Cossio,Palomo
, p. 1703 - 1712 (2007/10/02)
The development of a practical method for the preparation of vinylamino-β-lactams from Dane salts and Schiff bases is described. Among the reagents known to produce β-lactams from imines and acetic acids, only phenyl dichlorophosphate and 1-methyl-2-chloropyridinium iodide are suitable for the synthesis of vinylamino-β-lactams. Reaction of acetic acids with ethanolimine derivatives promoted by phenyl dichlorophosphate affords oxazolidines instead of β-lactams. Protection of the hydroxyl group as the trimethylsilyl ether in the starting Schiff bases provides a convenient route to the corresponding β-lactams instead of oxazolidines. Some observations on the scope of the method are made.
TRIPHENYLPHOSPHINE DIBROMIDE AND DIMETHYLSULFIDE DIBROMIDE AS VERSATILE REAGENTS FOR BETA-LACTAM SYNTHESIS
Cossio, Fernando P.,Ganboa, Inaki,Palomo, Claudio
, p. 3041 - 3044 (2007/10/02)
Triphenylphosphine dibromide and dimethylsulfide dibromide are efficient reagents for the direct synthesis of beta-lactams from carboxylic acids and imines avoiding the use of acid halides as starting materials.Synthesis of 4-imino-beta-lactams are also briefly described.A potential synthesis of N-unsubstituted beta-lactams is made.
