Asymmetric remote C-H functionalization: Use of internal olefins in tandem hydrometallation – isomerization – asymmetric conjugate addition sequences

Journal article

We describe catalytic asymmetric C–C formation using terminal alkyl-metal nucleophiles generated from internal olefins through a ‘chain-walking’ isomerization mechanism. Hydrometallation of internal olefins with the Schwartz reagent gives the least hindered alkyl-zirconocene after thermal (60°C in THF) isomerization. After switching the solvent from THF to dichloromethane, the alkyl-zirconocenes can be used in copper-catalyzed asymmetric conjugate additions. Addition to a variety of cyclic α,β-unsaturated species were achieved in modest (22–50 %) yield with high (84–92 % ee) enantioselectivity. This work demonstrates that remote C–H functionalization coupled with asymmetric C–C bond formation is possible, but the present procedures are limited in terms of yield and olefin scope.

Authors: Mola, L; Sidera, M; Fletcher, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: CSIRO Publishing
• Journal: Australian Journal of Chemistry
• Volume: 68
• Issue: 3
• Pages: 401-403
• Publication date: 2014-11-21
• Acceptance date: 2014-10-15
• DOI: https://dx.doi.org/10.1071/CH14556
• EISSN: 1445-0038
• ISSN: 0004-9425