Unexpected effect of the fluorine atom on the optimal ligand-to-palladium ratio in the enantioselective Pd-catalyzed allylation reaction of fluorinated enol carbonates.
The enantioselective Pd-catalyzed allylation reaction of fluorinated allyl enol carbonates is presented; a key feature of this transformation is the important effect of the ligand-to-palladium ratio on the enantioselectivity of the alpha-fluoroketones, since using a ligand excess (L/Pd ratio = 1.25 : 1) led to moderate results (30-76% ee), while using a L/Pd ratio <1 : 1.67 (to as low as 1 : 4) allowed the desired products to be obtained with high enantiopurity (up to 94% ee).
Bélanger
Etienne
E
Canada Research Chair in Organic and Medicinal Chemistry, Département de chimie, Université Laval, 1045 avenue de la Médecine, Québec, QC, Canada G1V 0A6.
Houzé
Clément
C
Guimond
Nicolas
N
Cantin
Katy
K
Paquin
Jean-François
JF
D000498:Allyl Compounds / Q000138:chemical synthesis; D002254:Carbonates / Q000737:chemistry*; D005461:Fluorine / Q000737:chemistry*; D008024:Ligands; D010165:Palladium / Q000737:chemistry*
D000498:Allyl Compounds; D002254:Carbonates; D008024:Ligands; D005461:Fluorine; D010165:Palladium