Ortho selectivity in SNAr substitutions of 2,4-dihaloaromatic compounds. Reactions with piperidine
作者:Michael D. Wendt、Aaron R. Kunzer
DOI:10.1016/j.tetlet.2009.11.087
日期:2010.1
A broad survey of aromatic compounds with halogens positioned both ortho and para to activating groups was studied in SNAr reactions with piperidine. Regioselectivities varied with the substituent group and the polarity of the solvent. Many activating groups exhibited an overall bias toward ortho-substitution, and this led in nonpolar solvents to very high ortho selectivity. More polar solvents uniformly
与卤素的芳族化合物的一个全貌定位两者邻位和对位,以活化基团S中进行了研究Ñ用哌啶的Ar反应。区域选择性随取代基和溶剂的极性而变化。许多活化基团表现出对邻位取代的总体偏向,这导致非极性溶剂具有很高的邻位选择性。极性更大的溶剂使产物比率均匀地向对位取代转移。提出的证据表明,通过氢键作为许多邻位的驱动因素,可以进行配位。观察到的选择性。所提供的数据表明,对于该反应类型,几种常见的活化基团的邻位导向能力具有一般性和综合实用性。