Poly-Boron, -Silicon, and -Gallium Lewis Acids by Hydrometallation of 1,5- and 1,8-Dialkynylanthracenes

• Published in: European journal of inorganic chemistry 2014-09, Vol.2014 (26), p.4294-4301
• Main Authors: Lamm, Jan-Hendrik, Horstmann, Jan, Nissen, Jan H., Weddeling, Jan-Henrik, Neumann, Beate, Stammler, Hans-Georg, Mitzel, Norbert W.
• Format: Article
• Language: English
• Subjects: Acids; Boranes; Derivatives; Hydroboration; Hydrogallation; Hydrosilylation; Lewis acid; Lewis acids; Mass spectrometry; Piers; Polycycles; Solid-state structures; Synthesis (chemistry); X ray diffraction
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201402376

1,5‐Dialkynylanthracenes and 1,8‐dialkynylanthracenes have been functionalised by a series of hydrometallation reactions, namely, hydrosilylation, hydroboration and hydrogallation. Nine anthracene‐based Lewis acidic compounds with a semiflexible organic framework bearing SiCl3, SiCl2Me, SiClMe2, B(C6F5)2 and GaCl2 substituents were obtained. In all cases, the substrate could be functionalised twice, and bidentate Lewis acids were obtained. By using Piers' borane [HB(C6F5)2], a fourfold‐substituted anthracene species functionalised with four extremely electronegatively substituted boron atoms could be generated in quantitative yield. All of the poly‐Lewis acids were characterised by multinuclear NMR spectroscopy and, in part, by mass spectrometry and X‐ray diffraction experiments. A series of B‐, Si‐ and Ga‐containing poly‐Lewis acids were synthesised by converting 1,5‐ and 1,8‐dialkynylanthracene derivatives in hydrometallation reactions. Some of the compounds reacted with diethyl ether, which demonstrates the variable behaviour of the Lewis acidic compounds towards Lewis basic molecules.