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2,8′‐Disubstituted‐1,1′‐Binaphthyls: A New Pattern in Chiral Ligands
Author(s) -
Vyskočil Štěpán,
Meca Luděk,
Tišlerová Iva,
Císařová Ivana,
Polášek Miroslav,
Harutyunyan Syuzanna R.,
Belokon Yuri N.,
Stead Russel M. J.,
Farrugia Louis,
Lockhart Stephen C.,
Mitchell William L.,
Kočovský Pavel
Publication year - 2002
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20021018)8:20<4633::aid-chem4633>3.0.co;2-n
Subject(s) - chemistry , stereochemistry , methyl acrylate , amination , enantioselective synthesis , enantiomer , medicinal chemistry , catalysis , organic chemistry , polymer , copolymer
The title binaphthyls 19 and 26 , which are the positional isomers of 2‐methoxy‐2′‐(diphenylphosphino)‐1,1′‐binaphthyl (MOP, 19 ) and 2‐amino‐2′‐hydroxy‐1,1′‐binaphthyl (NOBIN, 26 ), have been synthesized by Suzuki coupling as the key step ( 10 + 15 → 18 ), followed by functional group transformations, involving CP and CN bond formation ( 18 → 19 and 18 → 23 ). Racemic intermediate 22 was resolved by co‐crystallization with N ‐benzylcinchonidinium chloride and the absolute configuration determined by X‐ray crystallography. These novel binaphthyls are configurationally stable and, as such, potentially usable as chiral ligands in asymmetric reactions. Michael addition of the glycine‐derived enolate 40 to methyl acrylate, carried out in the presence of ( R )‐(−)‐ 27 as the chiral phase‐transfer catalyst, afforded L ‐glutamic acid ( S )‐(+)‐ 43 of 92 % ee (after hydrolysis of the primary product).