Ruthenium Catalyzed Bis-Homo-Diels-Alder [2+2+2] Cycloaddition
Synthetic organic chemistry is an integral part of pharmaceutical design and development, which builds upon past literature to create molecules that mimic nature. The synthesis of ring structures has long been a focus in synthetic organic chemistry as many biologically active molecules contain various ring systems. Cycloaddition reactions are a means of constructing rings ranging from three-membered rings to large macrocycles and can be thermally or photochemically allowed or require metal catalysts to proceed. This work examines the [2+2+2] Bis-Homo-Diels-Alder cycloaddition between 1,5- cyclooctadiene and various alkynes including: terminal and internal alkynes, alkynyl halides and alkynyl phosphonates. First, two commercially available ruthenium catalysts were identified as being able to catalyze this reaction and alkynes were screed for their reactivity towards this reaction. Next, alkynyl halides were used as partners in this reaction with the hopes that the halide moiety would be retained in the final product and provide a site for further modification. Lastly, the use of alkynyl phosphonates in this reaction was explored to synthesize an array of novel vinyl-phosphonate containing compounds.