Arylcalcium Iodides in Tetrahydropyran: Solution Stability in Comparison to Aryllithium Reagents
作者:Jens Langer、Mathias Köhler、Reinald Fischer、Feyza Dündar、Helmar Görls、Matthias Westerhausen
DOI:10.1021/om300508w
日期:2012.9.10
[(THP)2Li(μ-Ph)]2 (9) was prepared and used to unambiguously identify some of the products. In order to verify the formation of benzyllithium as one of the byproducts, an authentic sample of [(dme)Li(μ-CH2Ph]2 (8) was prepared. In THP, an inversion of the relative reactivity of 1 and 7 was observed and the calcium compound was found to be more reactive than its lithium analogue. The crystal structures of 1–9
用精细分散的钙粉还原四氢吡喃(THP)中的对位取代碘代苯,得到[[THP)4 Ca(C 6 H 4 -4-R)I]类型的芳基碘化碘,R = CH 3(1),Cl (2),Br(3),I(4),OCH 3(5)。未观察到钙向二卤代苯中插入2倍。该β - naphthylcalcium碘化物(THP)4钙(β -萘)I](6)也可以通过THP中的直接合成来访问。与THF相比,研究了THP中芳族钙化合物的耐久性,并观察到在室温下THP的寿命略有延长。此外,还研究了1及其与锂的对应物[(THP)2 Li} 2(μ-Tol)(μ-Br)](7)在与THP和THF反应中的相对反应性和选择性。α -金属化和随后的裂环作用在两种情况下用于THF中观察到的主要途径。在诱导降解反应7,几个副产物从碳锂产生的和令人惊讶地,由β -金属化反应进行鉴定,而1被发现更具选择性。制备了相关的[(THP)2 Li(μ-Ph)]