P2N2 Ligands in Catalysis for Organic Transformations

Anne Marie Beardall

Abstract

This thesis attempts to use Ru and Pd complexes ligated with 1,5-R-3,7-Rʹ-1,5-diaza-3,7-diphosphacyclooctane (P^R₂N^R’₂) ligands for organic transformations. Herein, intermolecular hydroamination of terminal alkynes using [Ru(Cp/Cp*)(P^R₂N^R’₂)(MeCN]PF₆ (Cp = cyclopentadienyl, Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl) was investigated but it resulted in the formation of two deactivation products. In contrast, intermolecular hydration was successful, and this is the first instance of intermolecular chemistry with Ru-P^R₂N^R’₂ complexes. Intermolecular hydroalkoxylation with 1-octyne and phenol was also successful, but an aryl alkyne substrate scope was unsuccessful. Linear alcohols resulted in the formation of an undesired acetal product, yet interesting selectivity for the Z product was observed with phenylacetylene and propanol as substrates. It was previously observed that Pd-P^R₂N^R’₂ complexes showed divergent selectivity for the linear or branched products dependent on the phosphorus R substituent in the Heck coupling of phenyltriflate and styrene. To understand the selectivity, reaction intermediates were synthesized, preliminary characterization was collected, and catalysis was performed.