Homocoupling of Silyl-protected Phenylacetylenes to Produce Glaser Products Through an Oxidative Process

Hanni, Claudi, Steven Jones, Jennifer Kolasinski, Clinton Mikek, Mariam Saco, and Matthew Mio

Our research focus has been generating coupled aryl acetylenes using various coupling reactions. Differently-substituted free acetylene benzene rings were homocoupled using an oxidative Glaser coupling reaction as shown below. No evidence of Glaser product 2 was found, even with numerous procedural modifications. This is likely due to the ether group in the ring, where the oxygen could be donating electron density to the ring which inhibits homocoupling. It was then decided that an electron withdrawing group would be used as the ring substituent and the acetylene would be protected by a TMS group. As shown in Scheme 2 below, the –X substituted benzene rings 3 were homocoupled to produce the Glaser product 4. Using GC-MS and TLC it was confirmed that the Glaser products 4 in Scheme 2 below were synthesized. The GC-MS and TLC analysis also confirmed that further purification was required.