Selective synthesis of 2-substituted pyridine N-oxides via directed ortho-metallation using Grignard reagents
作者:Hans Andersson、Magnus Gustafsson、Roger Olsson、Fredrik Almqvist
DOI:10.1016/j.tetlet.2008.09.104
日期:2008.11
Addition of i-PrMgCl to pyridine N-oxides in THF at −78 °C generates selectively an ortho-metallated species, which can be trapped with various electrophiles to generate 2-substituted pyridine N-oxides. Furthermore, by applying a double metal-catalyzed cross-coupling, direct arylation of the pyridine N-oxides is achieved.
在-78°C下,将i -PrMgCl加到THF中的吡啶N-氧化物中,可以选择性地生成邻金属化的物种,该物种可以被各种亲电试剂捕获,从而生成2-取代的吡啶N-氧化物。此外,通过施加双金属催化的交叉偶联,实现了吡啶N-氧化物的直接芳基化。