Lückert Paula L, Gilmer Jannik, Virovets Alexander, Lerner Hans-Wolfram, Wagner Matthias
Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Max-von-Laue-Straße 7 D-60438 Frankfurt (Main) Germany
Chem Sci. 2024 Nov 18;16(1):147-155. doi: 10.1039/d4sc06940d. eCollection 2024 Dec 18.
Despite their promising potential, , as ditopic, cooperatively binding Lewis acids, 9,10-dihydro-9,10-dialuminaanthracenes (DAA-R; R: terminal Al-bonded substituent) have remained unexplored for long due to the challenges in synthesizing the ligand-free species. We demonstrate that DAA-Me is accessible the reaction of 1,2-(MeSn)CH with AlMe, producing volatile SnMe as the sole byproduct. In non-coordinating solvents and in the solid state, DAA-Me exists as a dimer (DAA-Me). Treatment of (DAA-Me) with 4 equiv. AlBr cleaves the dimer, leads to quantitative Me/Br exchange, and forms the double AlBr adduct DAA-Br·(AlBr). Removal of AlBr with 2,2'-bipyridine gives free DAA-Br, which also dimerizes in the absence of bases to form (DAA-Br). (DAA-Me) and (DAA-Br) readily react with mono- (, pyridine) or ditopic Lewis bases (, potassium pyrazolide) to afford -diadducts or triptycene-type frameworks. Upon addition of [BuN]Br, DAA-Br·(AlBr) undergoes selective cleavage of Al-C bonds to produce the Br chelate complex of 1,2-(BrAl)CH, a valuable synthon for 1,2-dideprotonated benzenes.
尽管9,10-二氢-9,10-二铝蒽（DAA-R；R：末端与铝键合的取代基）作为双齿、协同结合的路易斯酸具有广阔的应用前景，但由于合成无配体物种存在挑战，长期以来一直未被探索。我们证明，通过1,2-(MeSn)CH与AlMe反应可得到DAA-Me，反应仅产生挥发性的SnMe作为唯一副产物。在非配位溶剂和固态中，DAA-Me以二聚体（DAA-Me）形式存在。用4当量的AlBr处理（DAA-Me）会裂解二聚体，导致定量的甲基/溴交换，并形成双AlBr加合物DAA-Br·(AlBr)。用2,2'-联吡啶除去AlBr可得到游离的DAA-Br，其在无碱情况下也会二聚形成（DAA-Br）。（DAA-Me）和（DAA-Br）很容易与单齿（如吡啶）或双齿路易斯碱（如吡唑钾）反应，生成双加合物或三棱柱型骨架。加入[BuN]Br后，DAA-Br·(AlBr)会发生Al-C键的选择性裂解，生成1,2-(BrAl)CH的Br螯合配合物，这是一种用于1,2-去质子化苯的有价值的合成子。
