Copper-catalyzed asymmetric conjugate addition of Grignard reagents to 1-(N,N-diisopropylcarbamoyloxy)-1-tosyl-1-alkenes
作者:Yue-Lei Chen、Dieter Hoppe
DOI:10.1016/j.tetasy.2009.06.001
日期:2009.7
A copper-catalyzed conjugate addition of Grignardreagents to 1-(N,N-diisopropylcarbamoyloxy)-1-tosyl-1-alkenes led to 1-(N,N-diisopropylcarbamoyloxy)-1-tosyl-2-branched alkanes. Various copper ligands were screened for this reaction. From certain substrates and allylmagnesium bromide, several Josiphos ligands gave low to moderate asymmetric inductions, along with good diastereoselectivity. The stereochemistry
1-(<i>N,N</i>-Diisopropylcarbamoyloxy)-1-tosyl-1-alkenes—<i>a</i><sup>2</sup><i>d</i><sup>1</sup> Synthons via Tandem Umpolung
作者:Yue-Lei Chen、Dieter Hoppe
DOI:10.1021/jo900347s
日期:2009.6.5
have been developed as an a2d1 synthon via tandem umpolung. Upon addition of Grignard reagents and further quench by carbonyl compounds, this synthon produces α,α′-branched-α′-oxygenated ketones. Strategically, this widely applicable method installs respectively a carbanion unit and a carbonyl unit formally onto the α-carbon and the carbonyl center of an aldehyde in one-pot.
1-(N,N- -Diisopropylcarbamoyloxy)-1-甲苯磺酰基烯烃已经被开发作为一个2 d 1点通过串联极性转换的合成子。在添加格利雅试剂和羰基化合物进一步骤冷的,这种合成子产生α,α ' -支化-α ' -oxygenated酮。从战略上讲,这种广泛应用的方法是在一个罐中分别将碳负离子单元和羰基单元分别正式安装在醛的α-碳和羰基中心上。