Cooperative activation with chiral nucleophilic catalysts and N-haloimides: enantioselective iodolactonization of 4-arylmethyl-4-pentenoic acids.
Chiral triaryl phosphates promote the enantioselective iodolactonization of 4-substituted 4-pentenoic acids to give the corresponding iodolactones in high yields with high enantioselectivity. N-Chlorophthalimide (NCP) is employed as a Lewis acidic activator and oxidant of I2 for the present iodolactonization. In combination with 1.5 equivalents of NCP, only 0.5 equivalents of I2 are sufficient to generate the iodinating reagent.
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603 (Japan) http://www.ishihara-lab.net.
Hidefumi
H
Nakatsuji
Yasuhiro
Y
Sawamura
Akira
A
Sakakura
Kazuaki
K
Ishihara
D002384:Catalysis; D003500:Cyclization; D005229:Fatty Acids, Monounsaturated / Q000737:chemistry*; D007094:Imides / Q000737:chemistry*; D007455:Iodine / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis / Q000737:chemistry*; D058116:Lewis Acids / Q000737:chemistry; D010797:Phthalimides / Q000737:chemistry; D013237:Stereoisomerism
D005229:Fatty Acids, Monounsaturated; D007094:Imides; D007783:Lactones; D058116:Lewis Acids; D010797:Phthalimides; C037431:phthalimide; D007455:Iodine; C009785:4-pentenoic acid
asymmetric catalysis; cyclization; iodine; lactones; organocatalysis