Article thumbnail
Location of Repository

2,8'-Disubstituted-1,1'-Binaphthyls: A New Pattern in Chiral Ligands

By Stephen C. Lockhart, Louis Farrugia, Pavel Kočovský, William L. Mitchell, Russel M.J. Stead, Yuri N. Belokon, Syuzanna R. Harutyunyan, Miroslav Polášek, Luděk Meca, Štěpán Vyskočil, Ivana Císařová and Iva Tišlerová

Abstract

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 C-P and C-N bond formation (18→19 and 18→23). Racemic intermediate 22 was resolved by cocrystallization 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).

Year: 2002
OAI identifier: oai:ub.rug.nl:dbi/4bc6cd8850024
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://stratingh.eldoc.ub.rug.... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.