Additions to Fe(CO)3-dienal complexes: dependence of diastereoselectivity on Lewis acid.
Lewis acid mediated additions to Fe(CO)3-2,4-dienal complexes are explored. Silyl enol ether and allylstannane nucleophiles both undergo aldehyde addition with good diastereoselectivity. However, with TiCl4 as the catalyst, the psi-exo diastereomer is the major product while with BF3.Et2O the psi-endo diastereomer is favored. Lewis acid/substrate interactions are studied by VT-NMR, and a hypothesis that accounts for the observed diastereoselectivity is presented.
Harvey
D F
DF
Department of Chemistry & Biochemistry-0358, University of California, San Diego, La Jolla 92093-0358, USA.
Selchau
V B
VB
D000447:Aldehydes; D002384:Catalysis; D005290:Ferric Compounds; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D013237:Stereoisomerism
D000447:Aldehydes; D005290:Ferric Compounds; D007202:Indicators and Reagents