283 Bifluorene Synthesis Via Cobalt Mediated C-C Bond Coupling

Thursday, November 5, 2009: 11:40 AM
Longhorn (Camino Real Hotel)
Christopher A. Bradley , Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX
Malik Al-Afyouni , Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX
Tiffany A. Huang , Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX
Attempted synthesis of fluorenyl Co(II) complexes via salt metathesis with cobalt(II) halides and substituted lithium fluorenides results in the preparation of bifluorene derivatives. Optimization of the reaction conditions permits in situ generated lithium fluorenide salts to be coupled in respectable to excellent yields. Based on radical trapping experiments, the reaction mechanism likely involves one electron reduction of cobalt and subsequent fluorenyl radical coupling. This method provides a simple means of forming hindered C-C bonds in molecules with applications to both materials science and organometallic chemistry, using an abundant and inexpensive coupling agent. Reaction scope and derivatization of the bifluorene products will also be discussed.