Toward the Ideal Synthesis: New Transition Metal catalyzed Reactions Inspired by Novel Medicinal Leads

Studies in our laboratory are directed at the advancement of synthesis, biology, and medicine. This lecture will focus on new transition metal-catalyzed reactions that have been inspired by biologically potent targets such as phorbol and Taxol ® and by the more general interest in producing syntheses that are concise, efficient, cost- and resource-effective, envi- ronmentally benign, quick, and simple to conduct—in essence, ideal. A special emphasis in our program is placed on new transition metal-catalyzed reactions that, in the absence of cat- alyst, would be forbidden or difficult to achieve. We have thus far reported the first examples of intramolecular metal-catalyzed (4+2), (5+2), and (4+4) cycloadditions, reactions that pro- duce 6-, 7-, and 8-membered rings, respectively. Recent advances in our (5+2) cycloaddition studies will be presented, including new catalysts for relative and absolute stereochemical control. We will also describe recyclable catalysts that can be used in water, thereby mini- mizing cost and environmental concerns about solvent waste streams. New multicomponent reactions will also be presented. Finally, we will report a new (6+2) cycloaddition that pro- duces an 8-membered ring.