Highly Enantioselective Epoxidation of cis-Olefins by Chiral Dioxirane
Hongqi Tian, Xuegong She, Lianhe Shu, Hongwu Yu and Yian Shi*
*Department of Chemistry, Colorado State University, Fort
Collins, Colorado 80523, Email: yian
lamar.colostate.edu
H. Tian, X. She, L. Shu, H. Yu, Y. Shi, J. Am. Chem. Soc., 2000, 122, 11551-11552.
DOI: 10.1021/ja003049d
Abstract
An enantioselective epoxidation for cis-olefins using a chiral ketone as catalyst and Oxone as oxidant gives products with high ee values for a number of cyclic and acyclic cis-olefins. The results show that chiral dioxiranes can also epoxidize cis-olefins in addition to trans-olefins and trisubstituted olefins in a high degree of enantioselectivity.
see article for more examples
proposed transition state for substrates with π-systems
An Efficient Catalytic Asymmetric Epoxidation Method
Z.-X. Wang, Y. Tu, M. Frohn, J.-R. Zhang, Y. Shi, J. Am. Chem. Soc., 1997, 119, 11224-11235.
B. Wang, O. A. Wong, M.-X. Zhao, Y. Shi, J. Org. Chem., 2008, 73, 9539-9543.
Key Words
Epoxides, Organocatalysis, Oxone, Shi Epoxidation
ID: J48-Y2000-680
