Literature DB >> 19090750

Structures of beta-amino ester enolates: new strategies using the method of continuous variation.

Lara R Liou1, Anne J McNeil, Gilman E S Toombes, David B Collum.   

Abstract

The solution structures of four enolates derived from beta-amino esters are investigated using (6)Li NMR spectroscopy in conjunction with the method of continuous variation (method of Job). Ensembles of homo- and heteroaggregated enolates are generated by mixing enantiomers of a single enolate (R/S mixtures), opposite antipodes of two different enolates (R/S' mixtures), and the same antipodes of two different enolates (R/R' mixtures). The numbers of observable aggregates and their dependence on the mole fraction of the two enolates confirm the hexamer assignments. Inherent symmetries observable in the (6)Li NMR spectra show the stereochemistry of chelation about the hexagonal drum.

Entities:  

Mesh：

Substances：

Year:  2008        PMID： 19090750      PMCID： PMC2701450          DOI： 10.1021/ja8016957

Source DB:  PubMed          Journal:  J Am Chem Soc        ISSN： 0002-7863            Impact factor:   15.419


  29 in total

1.  Lithium and Cesium Ion-Pair Acidities of Dibenzyl Ketone. Aggregation of Lithium and Cesium Ion Pairs of the Enolate Ion and Dianion(1)(,).

Authors:  Roustam Gareyev; James C. Ciula; Andrew Streitwieser
Journal:  J Org Chem       Date:  1996-07-12       Impact factor: 4.354

2.  Optimization of the beta-aminoester class of factor Xa inhibitors. Part 2: Identification of FXV673 as a potent and selective inhibitor with excellent In vivo anticoagulant activity.

Authors:  Kevin R Guertin; Charles J Gardner; Scott I Klein; Allison L Zulli; Mark Czekaj; Yong Gong; Alfred P Spada; Daniel L Cheney; Sebastian Maignan; Jean-Pierre Guilloteau; Karen D Brown; Dennis J Colussi; Valeria Chu; Christopher L Heran; Suzanne R Morgan; Ross G Bentley; Christopher T Dunwiddie; Robert J Leadley; Henry W Pauls
Journal:  Bioorg Med Chem Lett       Date:  2002-06-17       Impact factor: 2.823

3.  Structure and reactivity of mixed alkali metal alkoxide/aryloxide catalysts.

Authors:  R M Kissling; M R Gagné
Journal:  J Org Chem       Date:  2001-12-28       Impact factor: 4.354

4.  Determination of binding stoichiometry by the continuous variation method: the Job plot.

Authors:  C Y Huang
Journal:  Methods Enzymol       Date:  1982       Impact factor: 1.600

Review 5.  Lithium diisopropylamide: solution kinetics and implications for organic synthesis.

Authors:  David B Collum; Anne J McNeil; Antonio Ramirez
Journal:  Angew Chem Int Ed Engl       Date:  2007       Impact factor: 15.336

Review 6.  Modern aldol methods for the total synthesis of polyketides.

Authors:  Bernd Schetter; Rainer Mahrwald
Journal:  Angew Chem Int Ed Engl       Date:  2006-11-20       Impact factor: 15.336

7.  Synthesis of alpha-substituted beta-amino acids using pseudoephedrine as a chiral auxiliary.

Authors:  G Nagula; V J Huber; C Lum; B A Goodman
Journal:  Org Lett       Date:  2000-11-02       Impact factor: 6.005

8.  Amine- and ether-chelated aryllithium reagents-structure and dynamics.

Authors:  Hans J Reich; Wayne S Goldenberg; Aaron W Sanders; Kevin L Jantzi; C Christoph Tzschucke
Journal:  J Am Chem Soc       Date:  2003-03-26       Impact factor: 15.419

9.  Characterization of beta-amino ester enolates as hexamers via 6Li NMR spectroscopy.

Authors:  Anne J McNeil; Gilman E S Toombes; Sithamalli V Chandramouli; Benoit J Vanasse; Timothy A Ayers; Michael K O'Brien; Emil Lobkovsky; Sol M Gruner; John A Marohn; David B Collum
Journal:  J Am Chem Soc       Date:  2004-05-19       Impact factor: 15.419

10.  Lithium hexamethyldisilazide-mediated enolizations: influence of chelating ligands and hydrocarbon cosolvents on the rates and mechanisms.

Authors:  Peter F Godenschwager; David B Collum
Journal:  J Am Chem Soc       Date:  2007-09-12       Impact factor: 15.419
View more
  8 in total

1.  Structure determination using the method of continuous variation: lithium phenolates solvated by protic and dipolar aprotic ligands.

Authors:  Laura L Tomasevich; David B Collum
Journal:  J Org Chem       Date:  2013-07-15       Impact factor: 4.354

2.  Azaaldol condensation of a lithium enolate solvated by N,N,N',N'-tetramethylethylenediamine: dimer-based 1,2-addition to imines.

Authors:  Timothy S De Vries; Angela M Bruneau; Lara R Liou; Hariharaputhiran Subramanian; David B Collum
Journal:  J Am Chem Soc       Date:  2013-03-04       Impact factor: 15.419

3.  Lithium phenolates solvated by tetrahydrofuran and 1,2-dimethoxyethane: structure determination using the method of continuous variation.

Authors:  Timothy S De Vries; Anandarup Goswami; Lara R Liou; Jocelyn M Gruver; Emily Jayne; David B Collum
Journal:  J Am Chem Soc       Date:  2009-09-16       Impact factor: 15.419

Review 4.  Method of continuous variations: applications of job plots to the study of molecular associations in organometallic chemistry.

Authors:  Joseph S Renny; Laura L Tomasevich; Evan H Tallmadge; David B Collum
Journal:  Angew Chem Int Ed Engl       Date:  2013-10-24       Impact factor: 15.336

5.  Solid-State and Solution Structures of Glycinimine-Derived Lithium Enolates.

Authors:  Kyoung Joo Jin; David B Collum
Journal:  J Am Chem Soc       Date:  2015-11-10       Impact factor: 15.419

6.  Method of continuous variation: characterization of alkali metal enolates using ¹H and ¹⁹F NMR spectroscopies.

Authors:  Laura L Tomasevich; David B Collum
Journal:  J Am Chem Soc       Date:  2014-06-25       Impact factor: 15.419

Review 7.  My maize and blue brick road to physical organic chemistry in materials.

Authors:  Anne J McNeil
Journal:  Beilstein J Org Chem       Date:  2016-02-08       Impact factor: 2.883

8.  Mono-N-protected amino acid ligands stabilize dimeric palladium(ii) complexes of importance to C-H functionalization.

Authors:  Joseph J Gair; Brandon E Haines; Alexander S Filatov; Djamaladdin G Musaev; Jared C Lewis
Journal:  Chem Sci       Date:  2017-06-16       Impact factor: 9.825
  8 in total

北京卡尤迪生物科技股份有限公司 © 2022-2023.