Pushing the Lewis Acidity Boundaries of Boron Compounds With Non‐Planar Triarylboranes Derived from Triptycenes
- 2 September 2019
- journal article
- research article
- Published by Wiley in Angewandte Chemie International Edition
- Vol. 58 (47) , 16889-16893
Abstract
Bending the planar trigonal boron center of triphenylborane by connecting its aryl rings with carbon or phosphorus linkers gave access to a series of 9‐boratriptycene derivatives with unprecedented structures and reactivities. NMR spectroscopy and X‐ray diffraction of the Lewis adducts of these non‐planar boron Lewis acids with weak Lewis base revealed particularly strong covalent bond formation. The first Lewis adduct of a trivalent boron compounds with the Tf2N− anion illustrates the unrivaled Lewis acidity of these species. Increasing the pyramidalization of the boron center and using a cationic phosphonium linker resulted in an exceptional enhancement of Lewis acidity. Introduction of a phosphorus and a boron atom at each edge of a triptycene framework, allowed access to new bifunctional Lewis acid‐base 9‐phospha‐10‐boratriptycenes featuring promising reactivity for the activation of carbon‐halogen bonds.Keywords
Funding Information
- Fédération Wallonie-Bruxelles (2.5020.11)
- Fonds De La Recherche Scientifique - FNRS (F.4513.18, 2.5020.11, GEQ U.G006.15, RW/GEQ2016)
This publication has 72 references indexed in Scilit:
- Recognition of Aromatic Compounds by π Pocket within a Cage‐Shaped Borate CatalystAngewandte Chemie International Edition, 2012
- Recognition of Aromatic Compounds by π Pocket within a Cage‐Shaped Borate CatalystAngewandte Chemie, 2012
- Aryl(hydro)boranes: versatile building blocks for boron-doped π-electron materialsDalton Transactions, 2012
- Design of Neutral Lewis Superacids of Group 13 ElementsInorganic Chemistry, 2011
- Design of Bicyclic and Cage Boron Compounds Based on Allylboration of Acetylenes with AllyldichloroboranesOrganic Letters, 2009
- Simple Access to the Non‐Oxidizing Lewis Superacid PhF→Al(ORF)3 (RF=C(CF3)3)Angewandte Chemie International Edition, 2008
- Fluorinated 9-borafluorenes vs. conventional perfluoroaryl boranes — Comparative Lewis acidityCanadian Journal of Chemistry, 2005
- Über die Umsetzung von Lithium‐tetraalkylboranaten mit AlkylierungsmittelnEuropean Journal of Organic Chemistry, 1971
- The linear .DELTA.H-.DELTA.nu(sub C:O) relation for ethyl acetate adducts and its significance for donor-acceptor interactionsJournal of the American Chemical Society, 1968
- 103. Co-ordination compounds having carboxylic esters as ligands. Part II. Relative acceptor strengths of some Group III and IV halidesJournal of the Chemical Society (Resumed), 1962