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Chiral Inductor (chiral + inductor)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

ChemInform Abstract: Diastereoselective Alkylation of Acetoacetates of Chiral Inductors.

CHEMINFORM, Issue 4 2001
Synthetic Applications.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

An Efficient Asymmetric Synthesis of 2-Substituted 1,4-Benzodiazepin-3-one as a Potential Molecular Scaffold

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 8 2005
Nuria Cabedo
Abstract 2-Substituted 1,4-benzodiazepine-2-one compounds (9,12) were obtained by a highly diastereoselective alkylation of a seven-membered ring benzolactam (8) in the presence of (R)-phenylglycinol as a chiral inductor. The corresponding acid derivative (16) afforded a conformationally constrained structure suitable for preparing peptidomimetic analogues useful as a novel molecular scaffold. After cleavage of the chiral appendage this approach might also lead efficiently to enantiomerically pure 2-substituted benzodiazepines (15). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

Intramolecular Carbolithiation of Allyl o -Lithioaryl Ethers: A New Enantioselective Synthesis of Functionalized 2,3-Dihydrobenzofurans

CHEMISTRY - A EUROPEAN JOURNAL, Issue 18 2005
José Barluenga Prof. Dr.
Abstract A new and easy method for the diastereoselective synthesis of 3-functionalized 2,3-dihydrobenzofuran derivatives from allyl 2-bromoaryl ethers is described. The key step of this transformation involves an intramolecular carbolithiation reaction of allyl 2-lithioaryl ethers. The substituents in both the allyl and the aryl moieties play an important and decisive role in stopping the reaction at the benzofuran thus avoiding a ,-elimination reaction. Finally, this process is amenable to the synthesis of enantiomerically enriched compounds by using (,)-sparteine as a chiral inductor. Se describe un método nuevo y sencillo para la síntesis diastereoselectiva de derivados de 2,3-dihidrobenzofurano funcionalizados en la posición 3 a partir de alil 2-bromoaril éteres. El paso clave de esta transformación implica una reacción de carbolitiación intramolecular de alil 2-litioaril éteres. La presencia de sustituyentes tanto en el resto alílico como en el arílico desempeña un papel decisivo e importante para poder detener la reacción en el estadio de benzofurano, evitando así la reacción de , -eliminación. Finalmente, este proceso puede ser aplicado a la síntesis de compuestos enantioméricamente enriquecidos mediante el uso de (,)-esparteína como inductor quiral. [source]

Highly Stereoselective Synthesis of Novel Multistereogenic Bis - Bifunctional Ligands Based on [2.2]Paracyclophane- 4,7-quinone, their Structure Elucidation and Application in Asymmetric Catalysis

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1 2005
Natalia Vorontsova
Abstract Bis - bifunctional cis -4,7-diarylsubstituted-4,7-dihydroxy-4,7-dihydro[2.2]paracyclophanes 3,6 were synthesized by a highly diastereoselective reaction of ortho -substituted aryllithium reagents with [2.2]paracyclophane-4,7-quinone (1). Enantiomerically pure diols 3,5 were tested as chiral inductors in the enantioselective addition of diethylzinc to benzaldehyde (up to 93.5% ee). Acid dehydration of cis -4,7-di(2-methoxyphenyl)-4,7-dihydroxy-4,7-dihydro[2.2]paracyclophane (3) results in 4,7-dihydro-7,8-di(2-methoxyphenyl)[2.2]paracyclophane-4-one (8) , a planar chiral cyclohexadienone of the [2.2]paracyclophane series with a para -semiquinoid substructure. X-Ray investigations of compounds 3, 4 and 8 were performed. [source]