Reactions of phosphinites with oxide surfaces: a new method for anchoring organic and organometallic complexes.
Reactions of phosphinites with oxide surfaces: a new method for anchoring organic and organometallic complexes.
复制标题
次膦酸盐与氧化物表面的反应：锚定有机和有机金属配合物的新方法。
作者：
B. C. Vicente;Zheng Huang;M. Brookhart;A. Goldman;S. Scott
当在芳香骨架的对位上具有次膦酸酯取代基的钳形配位铱配合物被固定在γ-氧化铝上时，它成为烷烃转移脱氢的高效负载型催化剂。采用固体（31）P MAS NMR谱、溶液（1）H和（31）P{（1）H} NMR谱、IR和萃取产物的GC/MS分析研究了有机金属配合物与载体之间的相互作用的性质。次膦酸酯取代基通过与γ-氧化铝表面上的羟基反应而从钳形配体上裂解，从而通过芳环共价锚定复合物。类似的反应发生在二氧化硅上，也允许容易地接枝到该载体上。锚定羟基封端的氧化物载体上的均相催化剂的策略，通过[POR]-含配体取代基的选择性裂解的建议。
When a pincer-ligated iridium complex with a phosphinite substituent in the para-position of the aromatic backbone is immobilized on γ-alumina, it becomes a highly effective supported catalyst for the transfer-dehydrogenation of alkanes. The nature of the interaction between the organometallic complex and the support was investigated using solid-state (31)P MAS NMR spectroscopy, solution-state (1)H and (31)P{(1)H} NMR spectroscopy, IR and GC/MS analysis of extracted reaction products. The phosphinite substituent is cleaved from the pincer ligand by its reaction with hydroxyl groups on the γ-alumina surface, resulting in covalent anchoring of the complex via the aryl ring. A similar reaction occurs on silica, allowing for ready grafting onto this support as well. A strategy for anchoring homogeneous catalysts on hydroxyl-terminated oxide supports though the selective cleavage of [POR]-containing ligand substituents is suggested.