Michael addition reactions with eta2-coordinated anisoles: controlling the stereochemistry of the para and benzylic carbons.
Several eta(2)-coordinated anisole complexes were treated with various Michael acceptors in the presence of a Lewis or Bronsted acid to generate stable 4H-anisolium complexes. These reactions were found to proceed with high stereochemical control with predictable outcomes, provided that the moderate acid (NH(2)Ph(2))OTf was used and the complex was dissolved in an acidic solution. The stereochemistry is shown to originate from an unexpectedly high preference for one coordination diastereomer of the anisole complex in the solid state and a Diels-Alder like transition state for the Michael reaction.
Smith
Philip L
PL
Department of Chemistry, University of Virginia, P.O. 400319, Charlottesville, VA 22904-4319, USA.
Keane
Joseph M
JM
Shankman
Sarah E
SE
Chordia
Mahendra D
MD
Harman
W Dean
WD
D000840:Anisoles / Q000737:chemistry*; D001593:Benzyl Compounds / Q000737:chemistry*; D007700:Kinetics; D009942:Organometallic Compounds / Q000737:chemistry; D012211:Rhenium / Q000737:chemistry; D013237:Stereoisomerism
D000840:Anisoles; D001593:Benzyl Compounds; D009942:Organometallic Compounds; D012211:Rhenium