Fraile José M, García José I, Herrerías Clara I, Mayoral José A, Reiser Oliver, Socuéllamos Antonio, Werner Heiko
Departamento de Química Orgánica, Instituto de Ciencia de Materiales de Aragón, Facultad de Ciencias, Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain.
Chemistry. 2004 Jun 21;10(12):2997-3005. doi: 10.1002/chem.200305739.
As shown by theoretical calculations, azabis(oxazoline)-copper complexes are considerably more stable than the analogous bis(oxazoline)-copper complexes. This enhanced stability allows them to be efficiently immobilized by means of electrostatic interactions to different anionic supports, such as clays and nafion-silica nanocomposites, without the loss of a ligand, as is observed for bis(oxazolines). As a result, enantioselectivities of around 90 % ee are obtained in the cyclopropanation reaction between styrene and ethyl diazoacetate. Moreover, the solid catalyst is easily recoverable.
理论计算表明，氮杂双（恶唑啉）-铜配合物比类似的双（恶唑啉）-铜配合物稳定得多。这种增强的稳定性使它们能够通过静电相互作用有效地固定在不同的阴离子载体上，如粘土和全氟磺酸-二氧化硅纳米复合材料，而不会像双（恶唑啉）那样损失配体。结果，在苯乙烯与重氮乙酸乙酯的环丙烷化反应中获得了约90%ee的对映选择性。此外，固体催化剂易于回收。
