Catalytic enantioselective allylation of ketoimines.
A general catalytic allylation of simple ketoimines was developed using 1 mol % of CuF.3PPh(3) as catalyst, 1.5 mol % of La(O(i)Pr)(3) as the cocatalyst, and stable and nontoxic allylboronic acid pinacol ester as the nucleophile. This reaction constituted a good template for developing the first catalytic enantioselective allylation of ketoimines. In this case, using LiO(i)Pr as the cocatalyst produced higher enantioselectivity and reactivity than La(O(i)Pr)(3). Thus, using the CuF-cyclopentyl-DuPHOS complex (10 mol %) and LiO(i)Pr (30 mol %) in the presence of (t)BuOH (1 equiv) produced high enantioselectivity up to 93% ee from a range of aromatic ketoimines. Mechanistic studies indicated that LiO(i)Pr accelerates the reaction by increasing the concentration of an active nucleophile, allylcopper.
Wada
Reiko
R
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.
Shibuguchi
Tomoyuki
T
Makino
Sae
S
Oisaki
Kounosuke
K
Kanai
Motomu
M
Shibasaki
Masakatsu
M
D000473:Alkanes / Q000737:chemistry; D000498:Allyl Compounds / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D003517:Cyclopentanes / Q000737:chemistry; D005459:Fluorides / Q000737:chemistry; D007097:Imines / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D013237:Stereoisomerism
D000473:Alkanes; D000498:Allyl Compounds; D003517:Cyclopentanes; D007097:Imines; D009942:Organometallic Compounds; D010087:Oxides; D003300:Copper; D008094:Lithium; D005459:Fluorides