Conformational arm-wrestling: battles for stereochemical control in benzamides bearing matched and mismatched chiral 2- and 6-substituents
作者:Jonathan Clayden、Yann J. Y. Foricher、Madeleine Helliwell、Paul Johnson、David Mitjans、Victoria Vinader
DOI:10.1039/b514558a
日期:——
stereochemistry of an adjacent chiral substituent. With a chiral substituent in both ortho positions, matched/mismatched pairs of isomers result. Evidence for matched stereochemistry is provided by the clean NMR spectra of single conformers, while mismatching gives poor or unexpected selectivities in the formation of chiral substituents, or mixtures of amide conformers. Attempts to use the match-mismatch effect
与芳环相邻的叔酰胺基的取向可以由相邻的手性取代基的立体化学决定。在两个邻位都具有手性取代基时,会形成匹配/不匹配的异构体对。单一构象异构体的干净NMR光谱提供了匹配的立体化学证据,而错配在形成手性取代基或酰胺构象异构体的混合物时,选择性差或出乎意料。描述了尝试使用匹配-不匹配效应来选择对映异构体取代基的外消旋对,从而开发出“外消旋体-酯化”试剂,以及使用“匹配”来从化合物的材料中清除二胺的单一对映体的方法。对映体纯度不完全。