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Titolo:
Synthesis of chiral amino alcohols embodying the bispidine framework and their application as ligands in enantioselectively catalyzed additions to C=O and C=C groups
Autore:
Spieler, J; Huttenloch, O; Waldmann, H;
Indirizzi:
Max Planck Inst Mol Physiol, D-44227 Dortmund, Germany Max Planck Inst MolPhysiol Dortmund Germany D-44227 7 Dortmund, Germany
Titolo Testata:
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
fascicolo: 3, , anno: 2000,
pagine: 391 - 399
SICI:
1434-193X(200002):3<391:SOCAAE>2.0.ZU;2-6
Fonte:
ISI
Lingua:
ENG
Soggetto:
CONJUGATE ADDITION; EPHEDRINE DERIVATIVES; DIETHYLZINC; ALDEHYDES; COMPLEXES; SPARTEINE; REAGENTS; DEPROTONATION; ALKYLATION; CHALCONES;
Keywords:
asymmetric synthesis; chiral amino alcohol; bispidine; enantioselective catalysis;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
42
Recensione:
Indirizzi per estratti:
Indirizzo: Waldmann, H Max Planck Inst Mol Physiol, Otto Hahn Str 11, D-44227 Dortmund, Germany Max Planck Inst Mol Physiol Otto Hahn Str 11 Dortmund Germany D-44227
Citazione:
J. Spieler et al., "Synthesis of chiral amino alcohols embodying the bispidine framework and their application as ligands in enantioselectively catalyzed additions to C=O and C=C groups", EUR J ORG C, (3), 2000, pp. 391-399

Abstract

Two generally applicable routes for the synthesis of chiral amino alcoholsembodying the bispidine framework have been developed. In linear route A the bispidine framework is built up successively from chiral primary amines via intermediate formation of a piperidinone and a bispidinone. In convergent route B an achiral bispidine is formed first and then the N-substituentsare introduced by reaction of the nitrogen bases with chiral electrophiles. In order to determine if the bispidine core and its N-substituents can influence the steric course of enantioselective transformations, bispidine amino alcohols built up by these two routes were investigated as chiral Ligands in the enantioselectively catalyzed addition of diethylzinc to aldehydesand chalcone. In general, tridentate ligands containing one chiral amino alcohol fragment and a second amino substituent without a stereogenic centerwere more efficient than tetradentate ligands with two amino alcohol structural units. With the best Ligands the enantioselective addition of diethylzinc to aromatic and aliphatic aldehydes proceeded with 83-98% ee and the nickel-catalyzed addition of diethylzinc to chalcone was achieved with up to85% ee.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 23/01/20 alle ore 06:32:51