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(I)试剂(Togni试剂)适用于醇、硫醇和各种N、C亲核试剂等多种底物的选择性三氟甲基化反应。虽然碘烷被路易斯酸(亲电)金属化合物激活用于上述反应，但它们对亲核金属化合物的行为迄今很少被研究。在本项目的范围内，系统地探索了羧基碘烷和烷氧基碘烷与一系列简单的低价CO和PPh_3钴镍络合物的反应性。因此，金属原子的氧化三氟甲基化(例如M(0)到M(II)-CF3)是预期的，意味着正式的“Upolung”CF3+/CF3-。研究的重点是产物的性质和后续反应如何依赖于金属、氧化态、配体和所用的碘烷试剂。所得结果可为开发新的三氟甲基化反应和催化剂提供依据。

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.