Dötz Karl Heinz, Jahr Holger C
Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany.
Chem Rec. 2004;4(2):61-71. doi: 10.1002/tcr.20007.
Tricarbonyl chromium complexes of naphthalene derivatives are synthesized by chromium-templated [3 + 2 + 1]-benzannulation and subjected to thermally induced haptotropic rearrangement experiments. Thermodynamic and kinetic parameters for the metal shift demonstrate the influence of the arene substitution pattern. In turn, the chromium template may be tuned as well by phosphorus coligands which allow to accelerate or slow down the isomerization process; this effect quantitatively reflects the steric and electronic properties of the coligand sphere. Proper adjustment of the template allows for a photo-induced reverse migration of the chromium moiety which results in a switchable organometallic device. Experiments with enantiopure arene chromium complexes indicate a stereospecific metal migration. The rearrangement proceeds by an intramolecular mechanism in both directions. Haptotropic isomerization reactions are not limited to bicyclic arenes and can be extended from naphthalenes to phenanthrene or tetra- and pentacyclic heteroarene systems.
通过铬模板化的[3 + 2 + 1]-苯并环化反应合成萘衍生物的三羰基铬配合物，并进行热诱导的迁移重排实验。金属迁移的热力学和动力学参数证明了芳烃取代模式的影响。反过来，铬模板也可以通过磷配体进行调节，这可以加速或减缓异构化过程；这种效应定量地反映了配体球的空间和电子性质。对模板的适当调整允许铬部分进行光诱导的反向迁移，从而产生一种可切换的有机金属器件。对映体纯的芳烃铬配合物的实验表明了立体特异性的金属迁移。重排在两个方向上均通过分子内机制进行。迁移异构化反应不限于双环芳烃，并且可以从萘扩展到菲或四环和五环杂芳烃体系。
