Chiral Auxiliaries In Asymmetric Synthesis Research Articles

1,2-Amino Alcohols and Their Heterocyclic Derivatives as Chiral Auxiliaries in Asymmetric Synthesis.

1,2-Amino Alcohols and Their Heterocyclic Derivatives as Chiral Auxiliaries in Asymmetric Synthesis.

ChemInform Abstract: Benzopyranoisoxazolidines as Chiral Auxiliaries for Asymmetric Synthesis.

AbstractChemInform 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.

ChemInform Abstract: Synthesis of Optically Active Azetidine‐2,4‐dicarboxylic Acid and Related Chiral Auxiliaries for Asymmetric Synthesis.

AbstractChemInform 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.

ChemInform Abstract: Use of Pseudoephedrine as a Practical Chiral Auxiliary for Asymmetric Synthesis.

AbstractChemInform 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.

Benzopyranoisoxazolidines as Chiral Auxiliaries for Asymmetric Synthesis

The asymmetric alkylation of N-propionylisoxazolidines (2a and 2b), which are prepared by treatment of 1a and 1b with propionyl chloride and triethylamine, proceeds with high diastereoselectivity, even with β-branched alkyl triflates. The alkylated products 3 can be converted into the alcohols 4, aldehydes 5, and ketones 6 in high yields in one step with recovery of the auxiliary 1.

Synthesis of optically active azetidine-2,4-dicarboxylic acid and related chiral auxiliaries for asymmetric synthesis

(S)-1-Phenylethylamine has been used as a chiral auxiliary as well as a nitrogen atom donor in the synthesis of an enantiomeric pair of azetidine-2,4-dicarboxylic acids, the absolute configuration of one of which has been assigned on the basis of the X-ray structure and the known absolute configuration of the (S)-1-phenylethylamine moiety. Chiral auxiliaries of related C2-symmetric azetidines have also been prepared and their propionamides have been asymmetrically alkylated. The stereochemistry of the resulting products was compared with their analogues having different ring sizes.

Use of Pseudoephedrine as a Practical Chiral Auxiliary for Asymmetric Synthesis

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUse of Pseudoephedrine as a Practical Chiral Auxiliary for Asymmetric SynthesisAndrew G. Myers, Bryant H. Yang, Hou Chen, and James L. GleasonCite this: J. Am. Chem. Soc. 1994, 116, 20, 9361–9362Publication Date (Print):October 1, 1994Publication History Published online1 May 2002Published inissue 1 October 1994https://doi.org/10.1021/ja00099a076RIGHTS & PERMISSIONSArticle Views4932Altmetric-Citations214LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (269 KB) Get e-AlertsSupporting Info (2)»Supporting Information Supporting Information Get e-Alerts

Ephedrine‐Derived Imidazolidin‐2‐ones. Broad Utility Chiral Auxiliaries in Asymmetric Synthesis

The scope of the readily available (4R,5S)-1,5-dimethyl-4-phenylimidazolidin-2-one (4) and its 4-cyclohexyl analogue 6 as practical, efficient chiral auxiliaries has been demonstrated. The enolate chemistry of their N-acyl derivatives exhibits features which recommend their use in asymmetric synthesis. The stereoselective boron-mediated aldol as well as alkylation and acylation results are presented. The steric control benefit derived by conversion of phenyl to cyclohexyl is highlighted.

Arene Chromium Tricarbonyl Stabilised Benzylic Carbocations

The ability of the chromium tricarbonyl unit to stabilise benzylic carbocations and oxonium ions is described. We have investigated the use of arene chromium tricarbonyl complexes as chiral auxiliaries for asymmetric synthesis. The synthesis of homochiral tetrahydroisoquinolines, tetrahydrobenzazepines, and 2-aryltetrahydropyrans via intramolecular cyclisation of a nucleophile onto chromium tricarbonyl stabilised benzylic carbocations and oxonium ions is described. 1. Introduction 2. Evidence for the Chromium Tricarbonyl Stabilisation of Benzylic Carbocations 3. Acyclic Systems without ortho Substitution 3.1 Carbocations 3.2 Oxonium Ions 4. Bicyclic Complexes 4.1 (6-5) Ring Systems 4.2 (6-6) Ring Systems 5. ortho Substituted Acyclic Compounds 5.1 Carbocations 5.2 Oxonium Ions 6. Miscellaneous Applications of Chromium Tricarbonyl Stabilised Carbocations

A urea with non-planar nitrogen-bonding geometry

(4R,5S)-1,5-Dimethyl-4-phenylimidazolidin-2-one, C11H14N2O, M(r) = 190.2, orthorhombic, P2(1)2(1)2(1), a = 6.161 (2), b = 8.045 (3), c = 20.811 (6) angstrom, V = 1031.5 angstrom3, Z = 4, D(x) = 1.23 g cm-3, Mo Kalpha radiation, lambda = 0.71069 angstrom, mu = 0.75 cm-1, F(000) = 408, T = 293 K, R = 0.041 for 839 observed reflections. The N-methyl atom of this urea derivative, a chiral auxiliary in asymmetric synthesis, is partially pyramidalized [sum of angles at N = 349 (1)-degrees] to minimize steric repulsions between adjacent ring substituents.

Synthesis and Applications of Binaphthylic C2-Symmetry Derivatives as Chiral Auxiliaries in Enantioselective Reactions

In this review, after a general introduction devoted to show the importance of the role played by C 2 -symmetry chiral auxiliaries to provide high levels of stereoselection, a complete survey of the preparation and use of optically active 1, 1'-binaphthyl derivatives as chiral auxiliaries in asymmetric synthesis is attempted

The conformation of 3- endo-arylmethylisobornyl esters.

The conformation of the benzyl group in 3- endo-benzylisobornyl esters depends on the nature of the ester group, and changes into a position close to coplanar with the ester group as the carbonyl group of the ester becomes conjugated. The potential use of these alcohols as chiral auxiliaries in asymmetric synthesis is addressed.

ChemInform Abstract: Chiral Auxiliaries for Asymmetric Synthesis: Enantioselective Addition of Dialkylzincs to Aldehydes Catalyzed by Chiral 1,2‐Disubstituted Ferrocenyl Amino Alcohols.

AbstractChemInform 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.

Chiral auxiliaries for asymmetric synthesis: enantioselective addition of dialkylzincs to aldehydes catalyzed by chiral 1,2-disubstituted ferrocenyl amino alcohols

Chiral 1,2-disubstituted ferrocenyl amino alcohols derived from (R)- and (S)-N,N-dimethyl-1-ferrocenylethylamines catalyze the enantioselective addition of dialkylzincs to aldehydes to afford optically active S and R secondary alcohols. The degree of enantioselectivity increases with increased bulk of substituents near the C-O and C-N bonds of the catalyst. Catalysts with R chirality at the carbon bearing the amino group and planar S chirality at the ferrocene nucleus afford S alcohols, regardless of the chirality of the carbon bearing the hydroxy group

ChemInform Abstract: Camphor Derivatives as Chiral Auxiliaries in Asymmetric Synthesis

ChemInform Abstract: Camphor Derivatives as Chiral Auxiliaries in Asymmetric Synthesis

Camphor derivatives as chiral auxiliaries in asymmetric synthesis

Camphor derivatives as chiral auxiliaries in asymmetric synthesis

ChemInform Abstract: 8‐Phenylmenthol as a Chiral Auxiliary in Asymmetric Synthesis

ChemInform Abstract: 8‐Phenylmenthol as a Chiral Auxiliary in Asymmetric Synthesis