Diastereoselective construction of syn-α-oxyamines via three-component α-oxyaldehyde–dibenzylamine–alkyne coupling reaction: application in the synthesis of (+)-β-conhydrine and its analogues
作者:Sharad Chandrakant Deshmukh、Arundhati Roy、Pinaki Talukdar
DOI:10.1039/c2ob26007g
日期:——
variation allows construction of piperidine and pyrrolidine rings while a variation of side arm functionality is achieved by complete regioselective opening of epoxide by different organocopper ylides (Gilman reagents). A lactam–Cu(I) complexation motif is proposed which allows an intramolecular attack of ylides at the terminal epoxy carbon via the six-membered cyclic transition state. The present work
描绘了Cu(I)催化的α-氧醛-二苄基胺-炔烃偶联反应,用于构建具有优异收率和非对映选择性的α-氧胺。晶体结构分析和理论计算是也支持形成的SYN -α-羟基胺作为主要产品。该方法的应用解决了(+)-β-水合醇与具有两种不同多样性特征的类似物的合成。圆环尺寸的变化允许构造哌啶和吡咯烷环,而侧臂功能的变化是通过不同有机铜(Gilman试剂)对环氧化合物的完全区域选择性开放而实现的。提出了内酰胺-Cu(I)络合基序,该基团通过六元环状过渡态允许末端的环氧碳上的分子发生分子内攻击。本工作的特点是在八个步骤中以(26%)的产率合成了(+)-β-异水合柠檬酸,以21–28%的产率合成了其七个类似物。