Download PDF
Synfacts 2007(6): 0602-0602  
DOI: 10.1055/s-2007-968590
Synthesis of Materials and Unnatural Products
© Georg Thieme Verlag Stuttgart · New York

Highly Fluorescent BN-Phenanthrenes

Contributor(s): Timothy M. Swger, Zhihua Chen
M. J. D. Bosdet, C. A. Jaska, W. E. Piers*, T. S. Sorensen, M. Parvez
University of Calgary, Alberta, Canada
Further Information

Publication History

Publication Date:
22 May 2007 (online)

    Permissions and Reprints

Significance

The authors report a facile synthesis of a series of novel phenanthrenes (2-6) that contain a B=N functionality at the annulation points of the aromatic rings. The feasibility of this cyclo­isomerization was attributed to the enhanced nucleophilicity of the carbon atom adjacent to boron in the intermediates 1. Compared to well-known phenanthrene and analogues 7 and 8, compounds 2-6 displayed large bathochromic shifts in their fluorescence spectra, with emission maxima at 450-460 nm. In addition, their fluorescence quantum yields were significantly higher than that of phenanthrene. All these features indicated that the B=N functionality might be involved in the fluorogenic unit.