61458-04-6Relevant articles and documents
A new polymer-supported reagent for the synthesis of β-lactams in solution
Donati, Donate,Morelli, Costanza,Porcheddu, Andrea,Taddei, Maurizio
, p. 9316 - 9318 (2007/10/03)
A modified Mukaiyama reagent was prepared on a PS-DVB resin. This reagent was used for the preparation of β-lactams, using the Staudinger reaction. The products were obtained by generating the ketene from a carboxylic acid under sonication with the resin followed by reaction with the imine. Excess of the imine was removed by reduction followed by acid scavenging.
An improved method for the stereoselective synthesis of β-lactams from carboxylic acids and imines
Georg, Gunda I.,Mashava, Peter M.,Guan, Xiangming
, p. 581 - 584 (2007/10/02)
Carboxylic acids activated with Mukaiyama's reagent (2-chloro-N-methylpyridinium iodide) reacted with imines to produce β-lactams in good yields and with high stereoselectivity. The utilization of three equivalents of tripropylamine as the base was necess
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.
N,N-DIMETHYLCHLOROSULFITEMETHAMINIUM CHLORIDE (SOCl2-DMF) A VERSATILE DEHYDRATING REAGENT.
Arrieta, A.,Aizpurua, J. M.,Palomo, C.
, p. 3365 - 3368 (2007/10/02)
N,N-dimethylchlorosulfitemethaminium chloride formed from thionyl chloride and dimethylformamide was found and efficient reagent for the synthesis of acyl azides from carboxylic acids and nitriles from oximes.It is also highly efficient for the direct synthesis of beta-lactams from carboxylic acids and imines avoiding the use of acid chlorides.