Syntheses of β-lactams from acetic acids and imines induced by phenyl dichlorophosphate reagent
作者:Ana Arrieta、Fernando P. Cossio、Claudio Palomo
DOI:10.1016/s0040-4020(01)96484-1
日期:——
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 β-lactams. Protection of the hydroxyl group as the trimethylsilyl ether in the
Triphenylphosphine dibromide and dimethylsulfide dibromide as versatile reagents for beta-lactam synthesis
作者:Fernando P. Cossío、Iñaki Ganboa、Claudio Palomo
DOI:10.1016/s0040-4039(00)98613-1
日期:1985.1
Triphenylphosphinedibromide 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.
Remarkable ketene substituent dependent effect of photo irradiation on the diastereoselectivity in the Staudinger reaction
作者:Zhanhui Yang、Jiaxi Xu
DOI:10.1016/j.tetlet.2011.12.003
日期:2012.2
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 one of the most important means to regulate the diastereoselectivity of the products in the Staudinger reaction, whatever ketenes were generated from
Synthesis of 3-Alkoxy/Aryloxy-β-lactams Using Diazoacetate Esters as Ketene Precursors Under Photoirradiation
作者:Jiaxi Xu、Hengzhen Qi、Zhanhui Yang
DOI:10.1055/s-0030-1259485
日期:2011.3
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-β-lactams. diazoacetate - imine -ketene- β-lactam - photoirradiation - Staudinger reaction
Unprecedented stereoselectivity in the Staudinger reaction with polycyclic aromatic imines
作者:Bimal K Banik、Frederick F Becker
DOI:10.1016/s0040-4039(00)01126-6
日期:2000.8
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.