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Enantioselective aza-Friedel-Crafts reaction of furan with α-ketimino esters induced by a conjugated double hydrogen bond network of chiral bis(phosphoric acid) catalysts.

ABSTRACT: Chiral C ₂- and C ₁-symmetric BINOL-derived bis(phosphoric acid) catalysts, which have OP([double bond, length as m-dash]O)(OH)₂/OP([double bond, length as m-dash]O)(OH)(OR) moieties at the 2,2'-positions, were developed and used for the enantioselective aza-Friedel-Crafts reaction of 2-methoxyfuran with α-ketimino esters for the first time. The intramolecular conjugated double hydrogen bond network is a key to increasing the Brønsted acidity and preventing deactivation of the catalysts. Highly functionalized α-amino acid derivatives with a chiral quaternary carbon center could be transformed into versatile optically active N- and O-heterocycles and an α-aryl-substituted serine.

SUBMITTER: Hatano M

PROVIDER: S-EPMC6143995 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature

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Enantioselective aza-Friedel-Crafts reaction of furan with α-ketimino esters induced by a conjugated double hydrogen bond network of chiral bis(phosphoric acid) catalysts.

Hatano Manabu M Okamoto Haruka H Kawakami Taro T Toh Kohei K Nakatsuji Hidefumi H Sakakura Akira A Ishihara Kazuaki K

Chemical science 20180625 30

Chiral C 2- and C 1-symmetric BINOL-derived bis(phosphoric acid) catalysts, which have OP([double bond, length as m-dash]O)(OH)2/OP([double bond, length as m-dash]O)(OH)(OR) moieties at the 2,2'-positions, were developed and used for the enantioselective aza-Friedel-Crafts reaction of 2-methoxyfuran with α-ketimino esters for the first time. The intramolecular conjugated double hydrogen bond network is a key to increasing the Brønsted acidity and pr ...[more]

PMID: 30288231

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