Polyacenes are organic compounds that have multiple, fused, aromatic rings. These highly conjugated molecules often have interesting photonic and/or electronic properties that afford them the potential for application in a host of organoelectronic devices such as sensors, light-emitting diodes, photovoltaic devices and field-effect transistors. Here, we show the development and use of the domino hexadehydro-Diels–Alder reaction to synthesize structurally diverse polyacenes from acyclic polyyne precursors. The key event in these transformations is the successive reaction of multiple 1,3-butadiyne units with a series of in-situ-generated, diynophilic arynes. The polyyne substrates were designed to allow for rapid engagement of each progressively larger aryne following the initiating (and ratelimiting) production of the first reactive intermediate—the benzyne. We show that aryne-trapping reactions are broad in scope and that these cascade or domino processes can be quite efficient.
Bibliographical noteFunding Information:
The studies reported here were supported by the US Department of Health and Human Services (National Institute of General Medical Sciences; R01 GM-65597, now R35 GM-127097) and the National Science Foundation (CHE-1665389). The computational work was carried out using hardware and software made available through the University of Minnesota Supercomputing Institute (MSI). Some NMR spectral data were obtained with an instrument purchased with a grant from the NIH Shared Instrumentation Grant program (S10OD011952). The authors thank V.G. Young, Jr (University of Minnesota) for performing the X-ray diffraction analysis and F. Xu (University of Minnesota) for assistance with the collection of absorption and fluorescence spectra.