Pecak Jan, Fleissner Sarah, Veiros Luis F, Pittenauer Ernst, Stöger Berthold, Kirchner Karl
Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria.
Centro de Química Estrutural and Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av Rovisco Pais, 1049-001 Lisboa, Portugal.
Organometallics. 2021 Jan 25;40(2):278-285. doi: 10.1021/acs.organomet.0c00755. Epub 2021 Jan 5.
The synthesis, characterization, and catalytic activity of low-spin {CoNO} pincer complexes of the type [Co(PCP)(NO)(H)] are described. These compounds are obtained either by reacting [Co(PCP)(κ-BH)] with NO and EtN or, alternatively, by reacting [Co(PCP)(NO)] with boranes, such as NH·BH in solution. The five-coordinate, diamagnetic Co(III) complex [Co(PCP-Pr)(NO)(H)] was found to be the active species in the hydroboration of alkenes with anti-Markovnikov selectivity. A range of aromatic and aliphatic alkenes were efficiently converted with pinacolborane (HBpin) under mild conditions in good to excellent yield. Mechanistic insight into the catalytic reaction is provided by means of isotope labeling, NMR spectroscopy, and APCI/ESI-MS as well as DFT calculations.
描述了[Co(PCP)(NO)(H)]型低自旋{CoNO}钳形配合物的合成、表征及催化活性。这些化合物可通过使[Co(PCP)(κ-BH)]与NO和EtN反应制得，或者也可通过使[Co(PCP)(NO)]与硼烷（如溶液中的NH·BH）反应制得。发现五配位抗磁性Co(III)配合物[Co(PCP-Pr)(NO)(H)]是烯烃硼氢化反应中具有反马氏选择性的活性物种。一系列芳香族和脂肪族烯烃在温和条件下用频哪醇硼烷（HBpin）能高效转化，产率良好至优异。通过同位素标记、核磁共振光谱、大气压化学电离/电喷雾电离质谱以及密度泛函理论计算对催化反应进行了机理研究。
