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DOI: 10.1055/s-0028-1083487
Three-Component Synthesis of Epoxides and Aziridines via Sulfur Ylides
C. G. Kokotos, E. M. McGarrigle, V. K. Aggarwal*
University of Bristol, UK
Publication History
Publication Date:
23 October 2008 (online)
Significance
Reported is the three-component reaction of a vinyl sulfonium salt, a nucleophile and either an aldehyde or an imine to give epoxides and aziridines. The N-, O-, or C-nucleophile (R¹-), formed by reaction with the base, undergoes Michael addition to the sulfonium, and the resulting sulfonium ylide undergoes condensation with the aldehyde or imine to form the heterocycle. The success of the reaction was found to rely heavily on a low concentration of the sulfonium ylide relative to the concentration of the aldehyde or imine. This was achieved by using a large excess of the aldehyde or imine and by slow addition of the vinyl sulfonium salt to the reaction mixture. There is a good mechanistic discussion, which gives insight into the potential reasons for the variable diastereoselectivity.