Investigations in the reactivity of hypervalent trifluoromethyl iodanes towards low-valent cobalt and nickel complexes - a contribution to the insight into metal-mediated electrophilic trifluoromethylations

高价三氟甲基碘烷(I)试剂（“Togni试剂”）适用于许多底物如醇、硫醇和各种N和C亲核试剂的选择性亲电三氟甲基化。虽然碘烷在上述反应中被路易斯酸（亲电）金属化合物激活，但迄今为止很少研究它们对亲核金属化合物的行为。在本项目范围内，系统地探讨了羧基碘烷和烷氧基碘烷对一系列简单的低价CO和PPh3钴镍配合物的反应性。因此，预计金属原子会发生氧化三氟甲基化(例如M(0)到M(II)-CF3)，这意味着CF3+/CF3-形成正式的“非极性”。研究的重点是金属、氧化态、配体和碘烷试剂对产物性质和后续反应的影响。这些发现可为开发新的三氟甲基化反应和催化剂提供基础。

Hypervalent trifluoromethyl iodane(I) reagents ("Togni's reagents") are suitable for selective electrophilic trifluoromethylation of numerous substrates such as alcohols, thiols and various N and C nucleophiles. While the iodanes are activated for the mentioned reactions by lewis-acid (electrophilic) metal compounds, their behavior against nucleophilic metal compounds is rarely investigated so far. Within the scope of this project the reactivity of a carboxy iodane and a alkoxy iodane towards a series of simple low-valent CO and PPh3 complexes of cobalt and nickel is explored systematically. Thereby an oxidative trifluoromethylation of the metal atom is expected (e.g. M(0) to M(II)-CF3), implying a formal "umpolung" CF3+/CF3-. The focus of the research is how the properties and subsequent reactions of the products depend on metal, oxidation state, ligands and used iodane reagent. The so-gained findings can provide a basis for the development of new trifluoromethylation reactions and catalysts.