Literature DB >> 18399412

The barrier to enantiomerization of N-Boc-2-lithiopyrrolidine: the effect of chiral and achiral diamines.

Taher I Yousaf1, Roger L Williams, Iain Coldham, Robert E Gawley.   

Abstract

(-)-Sparteine and TMEDA dramatically lower both enthalpy and entropy of activation for the barrier to enantiomerization of N-Boc-2-lithiopyrrolidine in diethyl ether, whereas N,N'-diisopropylbispidine has little effect; the entropy of activation for enantiomerization is zero in the presence of TMEDA and slightly negative in the presence of sparteine; these data suggest a subtle change in mechanism of enantiomerization in the presence of TMEDA and sparteine.

Entities:  

Year:  2008        PMID： 18399412      PMCID： PMC2607545          DOI： 10.1039/b714302h

Source DB:  PubMed          Journal:  Chem Commun (Camb)        ISSN： 1359-7345            Impact factor:   6.222


  11 in total

1.  Dynamic thermodynamic resolution: control of enantioselectivity through diastereomeric equilibration.

Authors:  P Beak; D R Anderson; M D Curtis; J M Laumer; D J Pippel; G A Weisenburger
Journal:  Acc Chem Res       Date:  2000-10       Impact factor: 22.384

2.  Enantioselective synthesis of substituted pyrrolidines by dynamic resolution.

Authors:  Iain Coldham; Samuel Dufour; Thomas F N Haxell; Steven Howard; Graham P Vennall
Journal:  Angew Chem Int Ed Engl       Date:  2002-10-18       Impact factor: 15.336

3.  Reactivity series for s-BuLi/diamine-mediated lithiation of N-Boc pyrrolidine: applications in catalysis and lithiation of N-Boc piperidine.

Authors:  Matthew J McGrath; Julia L Bilke; Peter O'Brien
Journal:  Chem Commun (Camb)       Date:  2006-05-10       Impact factor: 6.222

4.  Dynamic thermodynamic resolution: solvent effects, mechanism, and an asymmetric 3,4,5-substituted benzazepine synthesis.

Authors:  Yong Sun Park; Eul Kgun Yum; Amit Basu; Peter Beak
Journal:  Org Lett       Date:  2006-06-22       Impact factor: 6.005

5.  Enantioselective Reactions of Configurationally Unstable alpha-Thiobenzyllithium Compounds.

Authors: 
Journal:  Angew Chem Int Ed Engl       Date:  2000-01       Impact factor: 15.336

6.  Dynamic thermodynamic and dynamic kinetic resolution of 2-lithiopyrrolidines.

Authors:  Iain Coldham; Samuel Dufour; Thomas F N Haxell; Jignesh J Patel; Graciela Sanchez-Jimenez
Journal:  J Am Chem Soc       Date:  2006-08-23       Impact factor: 15.419

7.  Dynamic kinetic resolution of N-Boc-2-lithiopyrrolidine.

Authors:  Iain Coldham; Jignesh J Patel; Graciela Sanchez-Jimenez
Journal:  Chem Commun (Camb)       Date:  2005-05-11       Impact factor: 6.222

8.  Complex-induced proximity effects: the effect of varying directing-group orientation on carbamate-directed lithiation reactions.

Authors:  K M Gross; P Beak
Journal:  J Am Chem Soc       Date:  2001-01-17       Impact factor: 15.419

9.  Barrier to enantiomerization of unstabilized, chelated, and dipole-stabilized 2-lithiopyrrolidines.

Authors:  Neil J Ashweek; Peter Brandt; Iain Coldham; Samuel Dufour; Robert E Gawley; Fredrik Haeffner; Rosalyn Klein; Graciela Sanchez-Jimenez
Journal:  J Am Chem Soc       Date:  2005-01-12       Impact factor: 15.419

10.  Configurational stability and transfer of stereochemical information in the reactions of enantioenriched organolithium reagents.

Authors:  Amit Basu; S Thayumanavan
Journal:  Angew Chem Int Ed Engl       Date:  2002-03-01       Impact factor: 15.336
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  4 in total

1.  Overview of Carbanion Dynamics and Electrophilic Substitutions in Chiral Organolithium Compounds.

Authors:  Robert E Gawley
Journal:  Top Stereochem       Date:  2010-01-01

2.  Synthetic applications and inversion dynamics of configurationally stable 2-lithio-2-arylpyrrolidines and -piperidines.

Authors:  Timothy K Beng; Jin Sun Woo; Robert E Gawley
Journal:  J Am Chem Soc       Date:  2012-08-27       Impact factor: 15.419

3.  The barrier to enantiomerization and dynamic resolution of N-Boc-2-lithiopiperidine and the effect of TMEDA.

Authors:  Iain Coldham; Daniele Leonori; Timothy K Beng; Robert E Gawley
Journal:  Chem Commun (Camb)       Date:  2009-08-06       Impact factor: 6.222

4.  Enantiomerization dynamics and a catalytic dynamic resolution of N-trimethylallyl-2-lithiopyrrolidine.

Authors:  Timothy K Beng; Taher I Yousaf; Iain Coldham; Robert E Gawley
Journal:  J Am Chem Soc       Date:  2009-05-27       Impact factor: 15.419
  4 in total

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