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Synthesis and Characterization of New Enantiopure 7,7′‐Disubstituted 2,2′‐Dihydroxy‐1,1′‐binaphthyls: Useful Ligands for the Asymmetric Allylation Reaction of Aldehydes
Author(s) -
Bandini Marco,
Casolari Sonia,
Giorgio Cozzi Pier,
Proni Gloria,
Schmohel Erick,
Spada Gian Piero,
Tagliavini Emilio,
UmaniRonchi Achille
Publication year - 2000
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/(sici)1099-0690(200002)2000:3<491::aid-ejoc491>3.0.co;2-n
Subject(s) - enantiopure drug , enantioselective synthesis , chemistry , ligand (biochemistry) , combinatorial chemistry , catalysis , absolute configuration , chiral ligand , asymmetric induction , stereochemistry , organic chemistry , biochemistry , receptor
As an extension of our interest in developing new enantioselective reactions based on the binaphthol privileged ligand , we report a simple approach to the synthesis of 7,7′‐disubstituted binaphthols. The commercially available 1,7‐dihydroxynaphthalene ( 1 ) was used as starting material for the preparation of the bromoderivatives 2 , which were oxidatively coupled to afford 3 , a key intermediate for the preparation of a variety of enantiopure substituted binaphthols ( 8 , 10 ). The absolute configuration of the new compounds was established by chiroptical analysis and by cholesteric induction. The optically active catalysts derived from the ligands 3 , 8 , 10 , 16 and 17 , complexed with Ti(O i Pr) 2 Cl 2 , Zr(O i Pr) 4 and ZrCl 4 (THF) 2 , were employed for the enantioselective addition of allyltributyltin to aldehydes. Finally, the influence of the substituents of the binaphthyl core on the transmission of the chiral information was also investigated.