Literature DB >> 18026563

Synthesis of Polymer-supported Chiral Lithium Amide Bases and Application in Asymmetric Deprotonation of Prochiral Cyclic Ketones.

Lili Ma1, Paul G Williard.   

Abstract

Polymer-supported chiral amines were effectively prepared from amino acid derivatives and Merrifield resin. Treatment of polymer-supported amines with n-butyllithium gave the corresponding polymer-suppported chiral lithium amide bases, which were tested in the asymmetric deprotonation reactions of prochiral ketones. The trimethylsilyl enol ethers were obtained in up to 82% ee at room temperature. The polymer-supported chiral lithium amides can be readily recycled and reused without any significant loss of reactivity or selectivity.

Entities:  

Year:  2006        PMID： 18026563      PMCID： PMC1868406          DOI： 10.1016/j.tetasy.2006.11.011

Source DB:  PubMed          Journal:  Tetrahedron Asymmetry        ISSN： 0957-4166


  9 in total

1.  New stable backbone linker resins for solid-phase peptide synthesis.

Authors:  Wenxin Gu; Richard B Silverman
Journal:  Org Lett       Date:  2003-02-20       Impact factor: 6.005

2.  Stereoselective reactions. XXXIV. Enantioselective deprotonation of prochiral 4-substituted cyclohexanones using chiral bidentate lithium amides having a bulky group instead of a phenyl group on the chiral carbon.

Authors:  M Toriyama; K Sugasawa; S Motohashi; N Tokutake; K Koga
Journal:  Chem Pharm Bull (Tokyo)       Date:  2001-04       Impact factor: 1.645

3.  New Homochiral Ligands Bearing Nonstereogenic Chirotopic Centers. Lithiated N,N'-Dialkylureas as Chiral Bases and Sterically Crowded Phosphines for Asymmetric Catalysis.

Authors:  Claus-Dieter Graf; Christophe Malan; Klaus Harms; Paul Knochel
Journal:  J Org Chem       Date:  1999-07-23       Impact factor: 4.354

4.  Asymmetric Addition of Alkyllithium to Chiral Imines: alpha-Naphthylethyl Group as a Chiral Auxiliary.

Authors:  Hideki Yamada; Tomohiko Kawate; Atsushi Nishida; Masako Nakagawa
Journal:  J Org Chem       Date:  1999-11-26       Impact factor: 4.354

5.  High Catalytic Activity of Chiral Amino Alcohol Ligands Anchored to Polystyrene Resins.

Authors:  Anton Vidal-Ferran; Nick Bampos; Albert Moyano; Miquel A. Pericàs; Antoni Riera; Jeremy K. M. Sanders
Journal:  J Org Chem       Date:  1998-09-04       Impact factor: 4.354

6.  Enantioselective deprotonation by chiral lithium amide bases: asymmetric synthesis of trimethylsilyl enol ethers from 4-alkylcyclohexanones.

Authors:  R Shirai; M Tanaka; K Koga
Journal:  J Am Chem Soc       Date:  1986-02-01       Impact factor: 15.419

7.  Enantioselective deprotonation reactions using polymer-supported chiral magnesium amide bases.

Authors:  K W Henderson; W J Kerr; J H Moir
Journal:  Chem Commun (Camb)       Date:  2001-09-21       Impact factor: 6.222

8.  High potency dipeptide sweeteners. 1. L-aspartyl-D-phenylglycine esters.

Authors:  J M Janusz; J M Gardlik; P A Young; R V Burkes; S J Stoll; A F Estelle; C M Riley
Journal:  J Med Chem       Date:  1990-03       Impact factor: 7.446

9.  New strategy for the construction of a monotetrahydrofuran ring in Annonaceous acetogenin based on a ruthenium ring-closing metathesis: application to the synthesis of Solamin.

Authors:  Guillaume Prestat; Christophe Baylon; Marie-Pierre Heck; Gabriela A Grasa; Steven P Nolan; Charles Mioskowski
Journal:  J Org Chem       Date:  2004-08-20       Impact factor: 4.354
  9 in total

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