A new regio- and stereoselective synthesis of β-enamino ketones with 3-ethoxycyclobutanones and substituted amines
作者:Pengfei Liu、Gang Shan、Shi Chen、Yu Rao
DOI:10.1016/j.tetlet.2011.12.040
日期:2012.2
A new method toward regio- and stereoselectivesynthesis of β-enamino ketones is described. Through Lewis acid-catalyzed reactions between 3-ethoxycyclobutanones and substituted amines, a variety of cis and trans β-enamino ketone derivatives were prepared with complete regio- and stereoselectivity at room temperature.
Enaminones are synthesized by the rhodium(II)-catalyzed denitrogenative rearrangement reaction of 1-(N-sulfonyl-1,2,3-triazol-4-yl)alkanols, which are readily prepared from propargylic alcohols and N-sulfonyl azides. Intramolecular 1,2-hydride (or -alkyl) migration occurs with an intermediary α-imino rhodium(II) carbenoid species generated through denitrogenation of the 1,2,3-triazol-4-yl moiety. The
烯胺酮是通过铑 (II) 催化的 1-(N-磺酰基-1,2,3-三唑-4-基) 烷醇的脱氮重排反应合成的,该反应很容易由炔丙醇和 N-磺酰基叠氮化物制备。分子内 1,2-氢化物(或-烷基)迁移与通过 1,2,3-三唑-4-基部分脱氮生成的中间 α-亚氨基铑 (II) 类卡宾物质一起发生。得到的烯胺酮被转化为各种杂环,并取代了 N-磺酰基。