Catalytic asymmetric methallylation of ketones with an (H8-BINOLate)Ti-based catalyst.
The first catalytic asymmetric methallylation of ketones is reported. The catalyst, which is generated from titanium tetraisopropoxide, H8-BINOL, 2-propanol, and tetramethallylstannane, reacts with ketones in acetonitrile to afford tertiary homoallylic alcohols in fair to excellent yields (55-99%) and fair to high enantioselectivities (46-90%). Ozonolysis of the resulting products provides access to chiral beta-hydroxy ketones, which are not readily prepared from direct asymmetric aldol reaction of acetone with ketones.
Kim
Jeung Gon
JG
P. Roy and Diana T. Vagelos Laboratories, University of Pennsylvania, Department of Chemistry, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, USA.
Camp
Elizabeth H
EH
Walsh
Patrick J
PJ
D002384:Catalysis; D007659:Ketones / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
D007659:Ketones; D014025:Titanium