为了避免在向酮中添加有机锂和有机镁试剂过程中发生不希望的去质子,通过与简单的亲核试剂(如有机铈和有机铜试剂)反应,将容易由内酰胺和酰胺制备的硫亚胺盐转化为2,2-二取代和2-单取代胺。研究了碘化亚硫碘鎓与有机铈试剂的反应,该有机铈试剂是通过将相应的锂试剂与无水氯化铈(III)进行金属转移而得到的。这些碘化亚硫碘鎓可作为良好的亲电子试剂,并接受烷基铈的双加成反应。新合成的胺的特征是1 H和1313 C NMR,IR和质谱。胺已转化为其盐酸盐,并通过COSY进行表征。这些盐酸盐已用临床分离的微生物,金黄色葡萄球菌,肺炎克雷伯菌,铜绿假单胞菌,鼠伤寒沙门氏菌和白色念珠菌进行了抗菌筛选。盐酸盐对这些细菌和真菌显示出相当好的活性。
Highly diastereoselective synthesis of 1,2-amino alcohols via nucleophilic addition of organocerium reagents to 4- and 5-oxazolidinonecarbaldehydes
作者:Andrew GH Wee、Fuxing Tang
DOI:10.1139/v98-112
日期:1998.7.1
The reaction of chiral, non-racemic 4- and 5-oxazolidinonecarbaldehydes, 6 and 13, with organocerium reagents proceeds efficiently with good to excellent diastereoselectivity to give syn and anti a...
New access to quaternary aminocyclobutanes via nucleophilic addition on cyclobutaniminium salts
作者:Amandine Kolleth、Alexandre Lumbroso、Gamze Tanriver、Saron Catak、Sarah Sulzer-Mossé、Alain De Mesmaeker
DOI:10.1016/j.tetlet.2016.06.097
日期:2016.8
the first [2+2] cycloaddition between a keteniminium salt and an alkene followed by a nucleophilic addition on the in situ generated cyclobuteniminium salts. This one-pot sequence enables the formation of quaternarycenters with high level of stereoselectivity and is largely applicable to the synthesis of highly strained intermediates as well as precursor for spirohydantoïns. Moreover, DFT calculations
Synthesis of Highly Substituted Cyclopropanes via the Quasi-Favorskii Rearrangement of α,α-Dichlorocyclobutanols
作者:Nicole Erin Behnke、Juha H. Siitonen、Stephen A. Chamness、László Kürti
DOI:10.1021/acs.orglett.0c01229
日期:2020.8.7
A method for the synthesis of highlysubstituted cyclopropanes via a quasi-Favorskii rearrangement is described. The method includes the combination two chemical transformations starting from α,α-dichlorocyclobutanones prepared via the [2 + 2] Staudinger ketene cycloaddition between either terminal- or cis-olefins and dichloroketene. First, α,α-dichlorocyclobutanones are reacted with organocerium reagents
While several efficient processes exist to effect the stereoselective creation of carbon-carbon bonds in the alpha- and beta-position of carbonyls, functionalization of the gamma-position is much more challenging. We disclose an alternative methodology exploiting the Cu-promoted S(N)2' reaction to achieve the addition of various nucleophiles upon the allylic lactones 5a-d which lead to the generation of the desired y-functionalized alpha,beta-unsaturated aldehydes 6 following in situ hydrolysis.