Intermolecular hydroamination of oxygen-substituted allenes. New routes for the synthesis of N,O-chelated zirconium and titanium amido complexes
作者:Rashidat O. Ayinla、Laurel L. Schafer
DOI:10.1039/c1dt10448a
日期:——
Intermolecular hydroamination of heteroatom-substituted allenes with a bulky arylamine was carried out using a bis(amidate) bis(amido) titanium(IV) complex (1) as a precatalyst. The reaction of 2,6-dimethylaniline with oxygen-substituted allene 2c or 2d in the presence of complex 1 gives the ketimine regioisomer as the exclusive product. Reduction of such ketimine products resulted in the formation
使用双(氨基甲酸酯)双(酰胺基)钛(IV)配合物(1)作为前催化剂,进行了由大体积的芳基胺进行的杂原子取代的烯丙基的分子间加氢胺化。的反应2,6-二甲基苯胺在配合物1的存在下,用氧取代的丙二烯2c或2d与酮亚胺的区域异构体一起作为排他性产物。此类酮亚胺产物的还原导致形成氨基醚,该氨基醚进一步用作形成N,O-螯合的五元钛环和锆环的配体。这样的空间要求N,O螯合配体导致单连接产物的高产率制备。所有配合物的固态分子结构均显示出金属中心周围扭曲的三角双锥几何形状,在金属和氧供体原子之间具有导数键。使用加氢胺作为配体制备关键步骤获得的这些新配合物本身也被证明是有用的环加氢胺预催化剂。