Thiapentalene precursors via t-butyl malonate esters

ORGN 532

Riley G. Jones, riley.jones@wku.edu and Chad A. Snyder, chad.snyder@wku.edu. Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY 42101
Metal n5-cyclopenta[c]thienyl complexes are of significant interest in both catalysis and materials chemistry. These relatives of the low-band-gap polymer polybenzo[2,3-c]thiophene show great promise as environmentally stable conductive polymers and as energy-efficient light-emitting diodes (LEDs) due to their unique electronic properties. Recently, studies have shown that cyclopenta[c]thiophene molecules are effective as photodynamic anticancer agents which are particularly aggressive toward leukemia cells. The current method of synthesizing these compounds is lengthy, costly, and has a very low yield. Our group has developed a novel one-step method to produce precursors of these compounds. This procedure increases product yields, eliminates the use of toxic and expensive solvents such as CCl4, and lowers the total number of synthetic steps involved in synthesis of thiapentalenes. These precursors are synthesized by C-C dialkylation using malonate esters to form fused five-membered rings. This new method is of value not only as "green" chemistry but also has potential to lower the cost of cancer treatments and electricity bills.