The challenging reaction of unactivated ortho-substituted aromatic ethers with Grignard reagents has been found to be most effectively catalysed using nickel complexes of less sterically hindered ligands. Air stable, cheap, commercially available [NiCl₂(PⁿBu₃)₂] stands out as an improved catalyst for this type of transformation. The improved results with this catalyst even extend to some couplings of a more activated substrate when examined at higher temperatures and at catalyst loadings down to 0.1 mol%. Unusual induction periods in these latter reactions have been related to the by-product magnesium salts acting as co-catalysts.

中文翻译：

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受阻较少的配体为镍催化芳族醚的格利雅交联提供了改进的催化剂†

已经发现，使用空间位阻较少的配体的镍配合物可以最有效地催化未活化的邻位取代的芳族醚与格氏试剂的挑战性反应。空气稳定，廉价，可商购的[NiCl ₂（P ⁿ Bu ₃）₂ ]是这类转化的改进催化剂。当在更高的温度和低至0.1摩尔％的催化剂负载下进行检查时，这种催化剂的改进结果甚至可以扩展到活化程度更高的底物的某些偶联。在后面这些反应中异常的诱导期与充当助催化剂的副产物镁盐有关。