Date of Thesis
Masters Thesis (Bucknell Access Only)
Master of Science
Catalysis, Gold, Silver-free, Acid-free, Solvent-free Catalysis, Gold, Silver-free, Acid-free, Solvent-free
ABSTRACT FOR PART I: HYDROPHENOXYLATION REACTIONS CATALYZED BY ARYLGOLD(I) COMPOUNDS Both carbine and phosphine ligated arylgold(I) compounds have been synthesized and investigated as single-component catalysts for the hydrophenoxylation of unactivated internal alkynes to yield vinyl ethers. Catalysts containing either JohnPhos or IPr/SIPr were found to be the most efficient catalysts during the screening process. Electron-withdrawing and electron-donating groups on the phenols were tolerated using these catalysts. No silver salts, acids, or solvents were needed for the catalysis, and either microwave or conventional heating afforded moderate to excellent yields of the vinyl ethers. ABSTRACT FOR PART II: ARYLGOLD(I) COMPOUNDS TO PROMOTE THE ADDITION OF DIPHENYLPHOSPHINIC ACID TO TERMINAL ALKYNES Arylgold compounds were investigated as single component catalysts for the addition of diphenylphosphinic acid to terminal alkynes using a microwave reactor. Both carbene and phosphine ligated compounds were investigated. It was found that (JohnPhos)Au(C6H4tBu) was the most efficient catalyst for this reaction. Terminal alkynes bearing electron withdrawing and electron donating groups resulted in a mixture of the 1,1 and 1,2 addition products. 4-Ethynyl-Â¿,Â¿,Â¿-trifluorotoluene and 1-bromo-4-ethynyl-benzene both required higher temperatures for higher conversion. 2-Ethynyltoluene and 2-ethynyl-1,3,5-trimethylbenzene were also used as substrates to investigate ortho substituted phenylacetylene derivatives. 2-Ethynyltoluene required both higher temperature and longer time for moderate conversation and 2-ethynyl-1,3,5-trimethylbenzene proved to be unreactive. The weakly deactivating -Br and the highly deactivating -CF3 aryl substituents resulted in lower 1,1 addition product yield and higher 1,2 addition yield. No silver salts, acids, or solvents were needed for the catalysis which is an improvement over previous methods to generate an active gold(I) species. The vinyl phosphinates were isolated as powders, gummy solids, or viscous oils affording moderate to excellent yields.
Fraccica, Daniel Vincent, "Development of Acid, Silver, and Solvent-Free Gold-Catalyzed Hydroelementation Reactions" (2014). Master’s Theses. 133.