Hydrophosphination of Vinylcyclopropane & Quinine for Metal Coordination Chemistry
Abstract
Phosphine ligands play a pivotal role in academia and the chemical industry, facilitating catalytic reactions for producing high value chemicals. Consequently, significant interest exists in developing new and efficient synthetic routes for new phosphorus-containing molecules. One key approach is hydrophosphination, where a phosphorus-hydrogen (P-H) bond is added across an unsaturated hydrocarbon (C=C or C≡C) to form a phosphorus-carbon (P-C) bond. This method maximizes atom economy, produces minimal by-products and can proceed with or without free radical initiators (highly reactive species with an unpaired electron), using either heat or light. This dissertation focuses on preparing new phosphine ligands through hydrophosphination. Chapter one details the UV light-induced ring opening of vinylcyclopropane with primary (RPH2) or secondary (R2PH) phosphines without initiators. The resulting tertiary phosphines were converted into air and moisture stable phosphine sulfides and phosphine oxide. Control experiments suggest these UV promoted reactions proceeded via a radical mechanism despite lacking an initiator. Chapter two explores the hydrophosphination of quinine, yielding chiral quininyl phosphine ligands, later converted into phosphine chalcogenides (P=S and P=O). These quininyl phosphine ligands were coordinated with iridium, rhodium, copper, and silver to produce metal complexes. Comprehensive characterization of the synthesized phosphines, phosphine chalcogenides, and metal complexes was performed using infrared (IR), ultraviolet-visible (UV-Vis), multi-nuclear spectroscopy, and high-resolution mass spectrometry.