1. Synthesis of Fischer Carbene Complexes for Use in Type II Intramolecular Diels-Alder Reactions Carolyn E. Anderson, Department of Chemistry and Biochemistry, Calvin College
Strained ring architectures have fascinated chemists for more than a century. As such, many efforts have been made to synthesize compounds containing strained rings, especially those which possess an alkene that is distorted from planarity by the constraints of the system. Using these molecules, one can hope to study the very nature of -bonding. However, the products obtained from these earlier efforts vary significantly in structure and composition, making a systematic study difficult.
One approach that has been utilized for the synthesis of these systems is the type II intramolecular Diels-Alder (t2IMDA) reaction. Unfortunately, the heat required to promote this transformation makes the inclusion of functional groups problematic. Fischer carbenes have been shown to accelerate intermolecular Diels-Alder reactions by as much as 104. By using Fischer carbene complexes, exemplified by compound 2, our group hopes to use t2IMDA reactions as a novel route for the constructions of libraries of strained ring containing compounds.
To date, we have successfully optimized the synthesis of the required salt 1 and our desired Fischer carbene-containing precursor 2. Further efforts will focus on preparing additional congeners of complex 2 and developing conditions for the t2IMDA reaction.