Catalytic asymmetric vinylation of ketones.
This communication describes the catalytic asymmetric 1,2-addition of vinylzinc reagents to aromatic, alpha,beta-unsaturated, and dialkyl ketones with enantioselectivities between 79 and 97% and with yields ranging from 84 to 98%. The products of these reactions are tertiary allylic alcohols with chiral quaternary centers that are useful in organic synthesis. The reaction involves hydrozirconation of a terminal alkyne, transmetalation to zinc, and addition to a ketone in the presence of a chiral titanium-based Lewis acid catalyst. The reactions proceed smoothly at room temperature in under 24 h.
Li
Hongmei
H
University of Pennsylvania, Department of Chemistry, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, USA.
Walsh
Patrick J
PJ
D000438:Alcohols / Q000138:chemical synthesis; D002384:Catalysis; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D020005:Propanols / Q000138:chemical synthesis; D013237:Stereoisomerism; D014753:Vinyl Compounds / Q000737:chemistry*
D000438:Alcohols; D007659:Ketones; D020005:Propanols; D014753:Vinyl Compounds; C006463:allyl alcohol