Development of Novel Heterogeneous Ruthenium Catalysts for Environmentally-benign Organic Transformations

开发对环境无害、高原子效率的有机转化有效的新型固体催化剂是迫切需要的。在本研究中，开发了ceo2或zro2负载的钌催化剂，这些催化剂对稳定芳香C-H键的直接芳基化和烷基化活化、通过稳定C-C键的裂解和重建进行烯丙基转移反应、羧酸在炔烃上的区域和立体选择性加成、不饱和烃的选择性交叉偶联以及通过氨基醇的脱氢环化合成吲哚非常有效。这些催化剂是可回收的，而不会损失显著的活性，钌类浸出到溶液中可以忽略不计。光谱研究，如XAFS和FTIR研究，揭示了在二氧化铈表面形成扭曲的Ru=O物质，这些物质将在原位转化为低价的活性Ru物质。

The development of novel solid catalysts effective for environmentally benign, highly atom-efficient organic transformations is highly desired. In the present study, CeO2-or ZrO2-supported ruthenium catalysts which are quite effective for the direct arylation and alkylation of stable aromatic C-H bond activation, the allyl transfer reactions via the cleavage and reconstruction of stable C-C bonds, the regio-and stereoselective addition of carboxylic acids to alkynes, the selective cross-coupling of unsaturated hydrocarbons, and the synthesis of indole via the dehydrogenative cyclization of an amino alcohol have been developed. These catalysts are recyclable without loss of significant activities, and the leaching of Ru species into solution is negligible. The spectroscopic studies, e. g. XAFS and FTIR studies, have revealed the formation of distorted Ru=O species on the surface of ceria, which would be transformed to low-valent active Ru species in situ.