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A Strategy for the Stereoselective Synthesis of Unsymmetric Atropisomeric Ligands: Preparation of NAPhePHOS, a New Biaryl Diphosphine
Author(s) -
Michaud Guillaume,
Bulliard Michel,
Ricard Louis,
Genêt JeanPierre,
Marinetti Angela
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(20020802)8:15<3327::aid-chem3327>3.0.co;2-f
Subject(s) - diphosphines , chemistry , stereoselectivity , intramolecular force , enantiomer , stereochemistry , catalysis , binap , atropisomer , chiral auxiliary , combinatorial chemistry , enantioselective synthesis , organic chemistry
MeO‐NAPhePHOS represents the first example of a new series of atropisomeric diphosphines bearing heterotopic biaryl moieties. The key step of its synthesis is the diastereoselective, intramolecular, Cu I ‐promoted coupling of 1‐iodonaphthol and 2‐iodo‐3‐methoxyphenol connected by a chiral tether. ( R,R )‐2,4‐Pentanediol is used as the chiral auxiliary in this highly selective reaction that leads to a single enantiomer of the title diphosphine. In the Ru‐promoted hydrogenations of carbonyl derivatives, NAPhePHOS affords enantioselectivity levels fully comparable to those of the C 2 ‐symmetrical analogues, BINAP and MeO‐BIPHEP respectively, thus showing that the lack of C 2 symmetry is not detrimental to the catalytic properties of atropisomeric ligands in these hydrogenation reactions.