Polymer-Supported Pyridine−Bis(oxazoline). Application to Ytterbium-Catalyzed Silylcyanation of Benzaldehyde
作者:Stina Lundgren、Serghey Lutsenko、Christina Jönsson、Christina Moberg
DOI:10.1021/ol0353363
日期:2003.10.1
coupling with 4-bromo-2,6-bis[(R)-4-phenyloxazolin-2-yl]pyridine and the resulting pybox derivatives were immobilized on Tentagel resins. Ytterbium(III) chloride complexes of the polymeric ligands catalyzed the addition of trimethylsilyl cyanide to benzaldehyde with 80-81% ee. The ligands were reused more than 30 times without any loss in selectivity or activity, and the metal complexes could be recovered
[反应:参见正文]将含有羟基和羧酸基团的末端乙炔与4-溴-2,6-双[(R)-4-苯基恶唑啉-2-基]吡啶进行Sonogashira偶联,并将所得的pybox衍生物固定化在Tentagel树脂上。聚合配体的氯化tter(III)配合物催化将三甲基甲硅烷基氰化物加到苯甲醛中,其ee含量为80-81%。配体可重复使用30次以上,而不会损失选择性或活性,并且金属络合物可回收并重复使用至少4次,尽管活性略有下降。