[化学]Dioxirane Epoxidations-conn.pdf

The Development of Dioxirane Mediated Enantioselective Epoxidation Reactions • Introduction to Dioxiranes • Early Epoxidations • Initial Asymmetric Epoxidations • Recent Advances, focusing on the Shi Group Brian Connell Evans Group Seminar 9/24/99 Dioxiranes: Cyclic Peroxides The First Synthesis (Talbott Thompson, 1972): Characterized by: F C 1) F (g) F3C UV 3 OLi 2 O IR F3C OLi 2) low temp GC F3C O 19F NMR mass spec Martiney (1977), Chapman and Hess (1984): Microwave spectroscopy: H H O3 H O C–H 1.090 Å C–O 1.387 Å O H H H O–O 1.515 Å Duncan and Shields (1986): R O2 R O hν R O C C O O R R R Burger et al (1994): F (g) or 2 F F O Cl2 or O stable in the gas phase C O O ClF F F Kirschfield et al (1994): Mes O2 Mes O C N2