Structural Evidence of Strong Calcium−π Interactions to Aryl Substituents Stabilized by Coexistent Agostic Bonds to Alkyl Groups
作者:Claas Loh、Susanne Seupel、Helmar Görls、Sven Krieck、Matthias Westerhausen
DOI:10.1021/om500135g
日期:2014.3.24
n-butyllithium and potassium bis(trimethylsilyl)amide in tetrahydrofuran (THF) yields the corresponding lithium (2a,b) and potassium derivatives (3a,b), with the alkali metals binding to the furanylmethylamido and pyridylmethylamido pockets. The calcium derivatives are accessible via a metathetical approach of the potassium complexes with calcium iodide in THF. Whereas bis[1-(2-furanylmethyl)-2-tert-butyl-3-(2
1-(2-呋喃基甲基)-(1a)和1-(2-吡啶基甲基)-2-叔丁基-3-(2,6-二异丙基苯基)-1,3-二氮杂-2-烯(1b)的金属化在四氢呋喃(THF)中用正丁基锂和双(三甲基甲硅烷基)酰胺钾制得相应的锂(2a,b)和钾衍生物(3a,b),碱金属与呋喃基甲基酰胺基和吡啶基甲基酰胺基键合。钙衍生物可通过钾与碘化钙在THF中的络合物的复分解方法获得。而双[1-(2-呋喃基甲基)-2-叔丁基-3-(2,6-二异丙基苯基)-1,3-二氮烯丙基]钙(4a)作为第三种加合物沉淀,双[1-(2-吡啶基甲基)-2-叔丁基-3-(2,6-二异丙基苯基)-1,3-二氮烯丙基]钙(4b)在没有溶剂大分子配体的情况下结晶。取代配位的溶剂分子,与芳基的强钙-π相互作用使配位球饱和。然而,双齿1,2-二甲氧基乙烷(DME)能够取代该侧键结合的芳基,从而导致双[1-(2-吡啶基甲基)-2-叔丁基-3-(2 ,6-二异丙基苯基)-1