Synthesis of Polycyclic Aromatics by Annulation of Arynes with 2-Halobiaryls

Significance

The preparation of triphenylenes and related heteroaromatic compounds from 2-halobiaryls and o-(trimethylsilyl)aryl triflates is reported. This reaction provides access to useful aromatic products in high yield (75-95%) from commercially available or easily accessed precursors. Best results are obtained using 2-iodobiaryls, but 2-bromobiaryls are also viable substrates. A single example of the annulation of bromotriphenylethylene is demonstrated. The observation that benzyne must be generated slowly under the reaction conditions was of crucial importance for obtaining high yields in these reactions.