Get access

Aromatic Homologation by Non-Chelate-Assisted RhIII-Catalyzed C[BOND]H Functionalization of Arenes with Alkynes

Authors


  • This work was supported by the Swiss National Science Foundation (137666) and the European Research Council under the European Community’s Seventh Framework Program (FP7 2007–2013)/ERC Grant agreement no. 257891.

Abstract

Larger condensed arenes are of interest owing to their electro- and photochemical properties. An efficient synthesis is the catalyzed aromatic annulation of a smaller arene with two alkyne molecules. Besides difunctionalized starting materials, directed C[BOND]H functionalization can be used for such aromatic homologation. However, thus far the requirement of either pre-functionalized substrates or suitable directing groups were limiting this approach. Herein, we describe a rhodium(III)-catalyzed method allowing the use of completely unbiased arenes and internal alkynes. The reaction works best with copper(II) 2-ethylhexanoate and decabromodiphenyl ether as the oxidant combination. This aromatic annulation tolerates a variety of functional groups and delivers homologated condensed arenes. Aside from simple benzenes, naphthalenes and higher condensed arenes provide access to highly substituted and highly soluble acenes structures having important electronic and photophysical properties.

Get access to the full text of this article

Ancillary