Description |
Electrocyclization reactions are commonly found in synthetic chemistry as a means to access cyclic systems and to define stereocenters. Rules for electrocyclization were developed by Woodward and Hoffman, and these rules allow chemists to predict the stereochemical outcome of potential electrocyclization reactions, as well as whether or not such reactions are likely to proceed under given conditions. While electrocyclization reactions are well understood from the singlet excited state, investigation into the stereochemical outcome of electrocyclizations taking place from the triplet excited state are lacking, as well as study into factors that may make the triplet excited state more likely. Previous work in the Rainier group showed evidence that the nature of the excited state in the electrocyclization of bis-aryl cycloalkenones was in some way dependent on the aromatic substitution. Additionally, previous work in the Rainier group has shown that the presence of TFA leads to a different stereochemical outcome for the reaction. This work discusses the synthesis of several pyridine-containing bis-aryl cyclohexenones and further investigates the impact of aromatic substitution on the nature of the excited state, namely the effect of electron poor heteroaromatics. Additionally, this work seeks to better understand the stereochemical outcomes of the photoelectrocyclization of pyridine containing bis-aryl cyclohexenones in the presence of TFA. |