Deolka Shubham, Govindarajan R, Khaskin Eugene, Vasylevskyi Serhii, Bahri Janet, Fayzullin Robert R, Roy Michael C, Khusnutdinova Julia R
Coordination Chemistry and Catalysis Unit Okinawa Institute of Science and Technology Graduate University 1919-1 Tancha Onna-son 904-0495 Okinawa Japan
Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences 8 Arbuzov Street Kazan 420088 Russian Federation.
Chem Sci. 2023 Jun 6;14(25):7026-7035. doi: 10.1039/d3sc01861j. eCollection 2023 Jun 28.
Nickel perfluoroethyl and perfluoropropyl complexes supported by naphthyridine-type ligands show drastically different aerobic reactivity from their trifluoromethyl analogs resulting in facile oxygen transfer to perfluoroalkyl groups or oxygenation of external organic substrates (phosphines, sulfides, alkenes and alcohols) using O or air as a terminal oxidant. Such mild aerobic oxygenation occurs through the formation of spectroscopically detected transient high-valent Ni and structurally characterized mixed-valent Ni-Ni intermediates and radical intermediates, resembling O activation reported for some Pd dialkyl complexes. This reactivity is in contrast with the aerobic oxidation of naphthyridine-based Ni(CF) complexes resulting in the formation of a stable Ni product, which is attributed to the effect of greater steric congestion imposed by longer perfluoroalkyl chains.
由萘啶型配体支撑的镍全氟乙基和全氟丙基配合物与其三氟甲基类似物相比，显示出截然不同的需氧反应性，导致使用氧气或空气作为终端氧化剂时，能轻易地将氧转移至全氟烷基或使外部有机底物（膦、硫化物、烯烃和醇）发生氧化反应。这种温和的需氧氧化反应通过形成光谱检测到的瞬态高价镍以及结构表征的混合价镍-镍中间体和自由基中间体而发生，类似于一些钯二烷基配合物所报道的氧活化过程。这种反应性与基于萘啶的镍（CF）配合物的需氧氧化反应形成对比，后者会形成稳定的镍产物，这归因于更长的全氟烷基链所带来的更大空间位阻效应。
