Department of Chemistry
Master of Science
A mild and efficient method to synthesize a variety of secondary and tertiary, as well as disecondary and ditertiary phosphines has been developed. Using reaction conditions that include cesium hydroxide, molecular sieves, and DMF, at room temperature, a wide range of alkyl halides has been coupled to primary or secondary phosphines to yield secondary or tertiary phosphines. Included were activated and aliphatic halides, as well as base sensitive functional groups. In addition, examples of disecondary and ditertiary ligands have also been prepared using similar reaction conditions. The synthesis of a P-N-P ligand was also accomplished with these procedures. Optically active phosphines can also be synthesized via this methodology. The "cesium effect," which gives rise to high efficiency and excellent chemoselectivity, was proved advantageous for these syntheses. The use of cesium hydroxide as the base of choice has many advantages over traditional methods for construction of the C-P bond. Important mechanistic concepts and synthetic applications will be addressed.
Honaker, Matthew, "Cesium Effect: A Mild and Efficient Synthesis of Secondary and Tertiary Phosphines" (2004). Masters Theses & Specialist Projects. Paper 527.