title: Sterically Demanding Unsymmetrical Diaryl-λ(3)-iodanes for Electrophilic Pentafluorophenylation and an Approach to α-Pentafluorophenyl Carbonyl Compounds with an All-Carbon Stereocenter.
abstract: A sterically demanding unsymmetrical pentafluorophenyl-triisopropylphenyl-λ(3)-iodane was developed as an effective reagent for the electrophilic pentafluorophenylation of various β-keto esters and a β-keto amide. 17 examples of α-pentafluorophenylated 1,3-dicarbonyl compounds 3 having a quaternary carbon center are provided. The resulting compounds were nicely transformed into chiral α-pentafluorophenyl ketones with an all-carbon stereogenic center in high yields and high enantioselectivities using asymmetric organocatalysis (up to 98 % ee) or asymmetric metal catalysis (up to 82 % ee).
authors.affiliation: Department of Nanopharmaceutical Science & Department of Frontier Materials, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya 466-8555 (Japan) E-mail: nozshiba@nitech.ac.jp.
authors.forename: Kohei
authors.initials: K
authors.lastname: Matsuzaki
authors.affiliation: Department of Nanopharmaceutical Science & Department of Frontier Materials, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya 466-8555 (Japan) E-mail: nozshiba@nitech.ac.jp.
authors.forename: Kenta
authors.initials: K
authors.lastname: Okuyama
authors.affiliation: Department of Nanopharmaceutical Science & Department of Frontier Materials, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya 466-8555 (Japan) E-mail: nozshiba@nitech.ac.jp.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Tokunaga
authors.affiliation: Rigaku Corporation 3-9-12 Mastubara-cho, Akishima, Tokyo 196-8666 (Japan).
authors.forename: Motoo
authors.initials: M
authors.lastname: Shiro
authors.affiliation: Department of Nanopharmaceutical Science & Department of Frontier Materials, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya 466-8555 (Japan) E-mail: nozshiba@nitech.ac.jp.
authors.forename: Norio
authors.initials: N
authors.lastname: Shibata
keywords: asymmetric organocatalysis; diaryl-λ3-iodanes; electrophilic pentafluorophenylation; palladium