Pang Yue, Rajeshkumar Thayalan, Scopelliti Rosario, Maron Laurent, Mazzanti Marinella
Group of Coordination Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) CH-1015 Lausanne Switzerland
Laboratoire de Physique et Chimie des Nano-objets, Institut National des Sciences Appliquées 31077 Toulouse Cedex 4 France
Chem Sci. 2025 Jul 23. doi: 10.1039/d5sc04248h.
Metal-arene complexes have recently attracted an increasing interest in f-element chemistry, but the functionalization of arenes mediated by uranium-arene interactions is limited to a single example. Here, we report a new uranium-biphenylene complex supported by a bulky rigid trianionic NNN-pincer ligand in which the uranium-arene interaction is able to promote C-C bond cleavage and functionalization with CO under mild conditions to yield a U-bound 9-fluorenone. Reduction of the U(iv)-pincer complex [NNN-U(THF)ClK(THF)] (1) with KC, in the presence of biphenylene, results in the terminal arene complex [NNN-U(THF)(biphenylene)][K(THF)] (3). DFT studies of 3 indicate the presence of two unpaired electrons located at the uranium center, in line with a U(iv) and a biphenylene dianion. Complex 3 undergoes C-C bond cleavage of the biphenylene ligand, affording [NNN-U(THF)(2,2'-biphenyl)][K(THF)] (4). DFT studies indicated that, due to the interaction between the biphenylene dianion and the uranium, a concerted ring opening reaction can occur on the strained four members ring to yield 4 while the uranium center retains a +IV oxidation state. Complex 4 undergoes facile CO insertion into the U-C bond, followed by the C-C bond formation, yielding [NNN-U(THF)(fluorenone)][K(THF)] (5). This work demonstrates the potential of uranium-arene interactions to promote arene activation and functionalization.
金属芳烃配合物最近在f元素化学领域引起了越来越多的关注，但由铀-芳烃相互作用介导的芳烃官能化仅限于一个实例。在此，我们报道了一种由庞大刚性三阴离子NNN钳形配体支撑的新型铀-联苯配合物，其中铀-芳烃相互作用能够在温和条件下促进C-C键裂解并与CO发生官能化反应，生成与铀结合的9-芴酮。在联苯存在下，用KC还原U(iv)-钳形配合物[NNN-U(THF)ClK(THF)] (1)，得到末端芳烃配合物[NNN-U(THF)(联苯)][K(THF)] (3)。对3的密度泛函理论研究表明，在铀中心存在两个未成对电子，这与U(iv)和联苯二价阴离子一致。配合物3对联苯配体进行C-C键裂解，得到[NNN-U(THF)(2,2'-联苯)][K(THF)] (4)。密度泛函理论研究表明，由于联苯二价阴离子与铀之间的相互作用，在应变的四元环上可以发生协同开环反应生成4，而铀中心保持+IV氧化态。配合物4易于将CO插入U-C键，随后形成C-C键，生成[NNN-U(THF)(芴酮)][K(THF)] (5)。这项工作证明了铀-芳烃相互作用促进芳烃活化和官能化的潜力。
