Conformational Preference and Remote (1,10) Stereocontrol in Biphenyl-2,2‘-dicarboxamides
作者:Jonathan Clayden、Andrew Lund、Latifa H. Youssef
DOI:10.1021/ol0167457
日期:2001.12.1
centrosymmetric epimers by heating. The stereoselectivity of the double lithiation-quench reaction is determined by the stereochemistry of the intermediate doubly lithiated species 2, either diastereoisomer of which may be formed stereospecfically from the corresponding atropisomeric dibromo compounds.[reaction: see text]
N,N,N'N'-四异丙基联苯-2,2'-二boxboxamide 1的双邻位锂化和亲电淬灭是非对映选择性的,从而得到3,3'-双取代产物3的手性C(2)对称阻转异构体。这些手性阻转异构体可通过加热以中等至良好的立体选择性转化为其非手性,中心对称差向异构体。双重锂化-猝灭反应的立体选择性由中间双锂化物质2的立体化学决定,其中任一非对映异构体都可以由相应的阻转异构二溴化合物立体形成。[反应:见正文]