The objective of this research program is to discover and develop new reaction methodology en route to the synthesis of complex bioactive molecules. Our proposed studies will focus on the development of methods that enable the synthesis of core structural and stereochemical subunits prevalent in many bioactive, polycyclic natural products. The processes that we develop will find utility in the synthesis of a variety of structures for which there is currently no efficient synthetic roadmap. Importantly, the methods presented in this application will be useful outside of the contexts described herein and will arm practitioners of synthetic chemistry (in academics, government, and industry) with a new set of important tools to access crucial building blocks for synthesis. The research proposed in this grant application is focused on a) the development of new palladium- and copper-catalyzed enantio-selective alkylation and protonation reactions that produce important building blocks for synthesis, b) the utilization of these novel methods for the synthesis of fused, spiro, and bridged ring system arrays, and c) the implementation of these new tools in the syntheses of numerous natural and non-natural bioactive small molecules. Specifically, we outline approaches to variecolin, przewalskin B, the rocaglate lignans, and the communesin alkaloids. These molecules are important from a biological standpoint, but also serve as a testing ground for our new technologies. As a consequence of this approach, we will have access to a) novel, medicinally relevant structures, b) a general platform for their synthesis, and c) new synthetic methodology that will benefit a host of diverse applications.