Engineering a small HOMO-LUMO gap and intramolecular C-H borylation by diborene/anthracene orbital intercalation

Wang, Sunewang R, Arrowsmith, Merle, Böhnke, Julian, Braunschweig, Holger, Dellermann, Theresa, Dewhurst, Rian, Kelch, Hauke, Krummenacher, Ivo, Mattock, James D, Müssig, Jonas, Thiess, Thorsten, Vargas, Alfredo and Zhang, Jiji (2017) Engineering a small HOMO-LUMO gap and intramolecular C-H borylation by diborene/anthracene orbital intercalation. Angewandte Chemie International Edition, 56 (27). pp. 8009-8013. ISSN 1433-7851

[img] PDF - Accepted Version
Restricted to SRO admin only until 6 June 2018.

Download (813kB)

Abstract

The diborene 1 was synthesized by reduction of a mixture of 1,2-di-9-anthryl-1,2-dibromodiborane(4) (6) and trimethylphosphine with potassium graphite. The X-ray structure of 1 shows the two anthryl rings to be parallel and their π(C14) systems perpendicular to the diborene π(B=B) system. This twisted conformation allows for intercalation of the relatively high-lying π(B=B) orbital and the low-lying π* orbital of the anthryl moiety with no significant conjugation, resulting in a small HOMO-LUMO gap (HLG) and ultimately an anthryl C-H borylation. The HLG of 1 was estimated to be 1.57 eV from the onset of the long wavelength band in its UV-vis absorption spectrum (THF, λonset = 788 nm). The oxidation of 1 with elemental selenium afforded diboraselenirane 8 in quantitative yield. By oxidative abstraction of one phosphine ligand by another equivalent of elemental selenium, the B-B and C1-H bonds of 8 were cleaved to give the cyclic 1,9-diborylanthracene 9.

Item Type: Article
Schools and Departments: School of Life Sciences > Chemistry
Subjects: Q Science > QD Chemistry
Depositing User: Alfredo Vargas
Date Deposited: 05 Jun 2017 08:13
Last Modified: 11 Jul 2017 19:57
URI: http://sro.sussex.ac.uk/id/eprint/68175

View download statistics for this item

📧 Request an update