The industrial process of hydroformylation or the oxo process has been used for many years in the production of aldehydes from alkenes. Different metals have been used as efficient catalysts for hydroformylation, in which linear and branched aldehydes are the products obtained; therefore, the development of new catalysts for hydroformylation with high selectivity to aldehydes is important. Rhodium complexes 6–9 were synthesized using [RhCl(CO)2]2, or [RhCl(COD)]2, with either pyrazolylpyridyl N′N′N pincer ligands or a pyrazolylpyridyl N′N ligand. These complexes were then evaluated as catalyst precursors in the hydroformylation reaction using a variety of alkenes. The catalysts all showed activity in hydroformylation but the most active catalyst was methyl-substituted pyrazolyl–rhodium complex 7 following optimization of temperature, syngas pressure and amount of catalyst. Other olefinic substrates were used for hydroformylation in the presence of 7 under the optimum hydroformylation conditions. Undecene and dodecene as substrates only showed minimal formation of aldehydes with predominantly isomerization of the alkene being observed.

中文翻译：

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N'N'N 钳和 N'N 双齿（吡唑基吡啶基）Rh(I) 配合物作为烯烃加氢甲酰化的催化剂前体

多年来，加氢甲酰化或羰基合成法的工业过程已用于从烯烃生产醛。不同的金属已被用作加氢甲酰化的有效催化剂，其中得到的产物是直链和支链醛；因此，开发对醛类具有高选择性的加氢甲酰化新催化剂具有重要意义。铑配合物 6-9 是使用 [RhCl(CO)2]2 或 [RhCl(COD)]2 与吡唑基吡啶基 N'N'N 钳形配体或吡唑基吡啶基 N'N 配体合成的。然后将这些配合物作为使用各种烯烃的加氢甲酰化反应中的催化剂前体进行评估。催化剂均显示出加氢甲酰化活性，但在优化温度后，活性最高的催化剂是甲基取代的吡唑基-铑配合物 7，合成气压力和催化剂用量。在最佳加氢甲酰化条件下，在 7 存在下使用其他烯烃底物进行加氢甲酰化。十一烯和十二烯作为底物仅显示出极少的醛形成，观察到主要是烯烃的异构化。