This proposal details the development of a family of catalytic protocols for the cyclization/addition of functionalized dienes and related substrates such as eneallenes, enones and imino olefins which display the activity, selectivity, generality, and functional group compatibility suitable for application to organic synthesis. The significance of this project stems from both the wealth of biologically active carbocyclic and heterocyclic molecules and the paucity of diastereo- and enantioselective annulation protocols. Electrophilic late transition metal complexes such as (phen)Pd(Me)(OEt2)(+)BAr4(-)(phen = 1,10-phenanthroline, Ar = 3.5 C6H3(CF3)2) (1) display a unique combination of high activity and low oxophilicity and will therefore be employed as cyclization/addition catalysts. Significantly, preliminary results point to the potential of this approach. Specifically, 1 has proven a highly active and highly tolerant catalyst for the cyclization /hydrosilylation of a range of functionalized 1,6-dienes to form silylated cyclopentane derivatives in good yield and with excellent regio- and diasteroselectivity. More importantly, continued effort in this area has the potential to achieve the goals of this proposal. Realization of these goals would produce a powerful tool for the synthesis of naturally occurring and pharmacologically active carbocycles and heterocycles.