Catalysis Research Center & Department of Chemistry, Technische Universität München, Ernst-Otto-Fischer-Strasse 1, 85747, Garching, Germany.
Angew Chem Int Ed Engl. 2017 Dec 4;56(49):15733-15736. doi: 10.1002/anie.201709921. Epub 2017 Nov 14.
We present the first [2]rotaxane featuring a functional organometallic host. In contrast to the known organic scaffolds, this assembly shows a high post-synthetic modifiability. The reactivity of the Ag pillarplex host is fully retained, as is exemplified by the first transmetalation in a rotaxane framework to provide the respective Au analogue. Additionally, a transformation under acidic conditions to give a purely organic [3]rotaxane is demonstrated which is reversible upon addition of a suitable base, rendering the assembly a pH-dependent switch. Hereby, it is shown that the mechanically interlocked nature of the system enhances the kinetic stability of the NHC host complex by a factor of >1000 and corresponds to the first observation of a stabilizing "rotaxand effect".
我们呈现了第一个具有功能化有机金属主体的轮烷。与已知的有机支架相比，该组装体具有很高的后合成修饰能力。Ag 柱芳烃主体的反应性得以完全保留，例如在轮烷骨架中首次进行的转金属化反应，得到了相应的 Au 类似物。此外，还证明了在酸性条件下进行的转化可以得到纯有机的[3]轮烷，加入合适的碱后可以可逆地得到该轮烷，使该组装体成为一个 pH 依赖型开关。由此表明，该体系的机械互锁性质通过因子>1000增强了 NHC 主体配合物的动力学稳定性，这也是首次观察到稳定的“轮烷效应”。
