A gold-catalysed enantioselective Cope rearrangement of achiral 1,5-dienes. Conference Paper uri icon

abstract

  • Since the discovery of the Cope rearrangement in the 1940s, no asymmetric variant of the rearrangement of achiral 1,5-dienes has emerged, despite the successes that have been achieved with its heteroatom variants (Claisen, aza-Cope, and so on). This article reports the first example of an enantioselective Cope reaction that starts from an achiral diene. The new gold(I) catalyst derived from double Cl(-)-abstraction of ((S)-3,5-xylyl-PHANEPHOS(AuCl)(2)), has been developed for the sigmatropic rearrangement of alkenyl-methylenecyclopropanes. The reaction proceeds at low temperature and the synthetically useful vinylcyclopropane products are obtained in high yield and enantioselectivity. Density functional theory calculations predict that: (1) the reaction proceeds via a cyclic carbenium ion intermediate, (2) the relief of strain in the methylenecyclopropane moiety provides the thermodynamic driving force for the rearrangement and (3) metal complexation of the transition-state structure lowers the rearrangement barriers.

published proceedings

  • Nat Chem

author list (cited authors)

  • Felix, R. J., Weber, D., Gutierrez, O., Tantillo, D. J., & Gagn, M. R.

citation count

  • 117

complete list of authors

  • Felix, Ryan J||Weber, Dieter||Gutierrez, Osvaldo||Tantillo, Dean J||Gagné, Michel R

publication date

  • January 2012