Well-Defined Silica Grafted Molybdenum Bis(imido) Catalysts for Imine Metathesis Reactions

Novel
site-isolated tetracoordinated molybdenum complexes possessing
bis­(imido) ligands, [(Si–O)2Mo­(NR)2] (R = t-Bu, 2,6-C6H3-i-Pr2), were immobilized on partially
dehydroxylated silica (SiO2‑200) by a rigorous surface
organometallic chemistry protocol. The newly developed materials adorned
with bis­(imido) functional units, which were previously exploited
mainly as spectator ligands on silica-supported olefin metathesis
molybdenum catalysts, are found to be efficient heterogeneous catalytic
systems for imine cross metathesis under mild conditions.

新型位点隔离的四配位钼配合物，其结构式为[(≡Si-O)₂Mo(=NR)₂]（其中R为叔丁基（t-Bu）、2,6-二异丙基苯基（2,6-C₆H₃-i-Pr₂）），通过严格的表面有机金属化学合成方案被固定于部分脱羟基二氧化硅（SiO₂-200）载体上。此前，双亚胺功能单元主要作为二氧化硅负载型钼基烯烃复分解催化剂的旁观配体被研究；本研究中新开发的负载该功能单元的材料，在温和条件下可作为高效催化亚胺交叉复分解反应的多相催化体系。