Use of Pseudoephedrine as a Practical Chiral Auxiliary for Asymmetric Synthesis
作者:Andrew G. Myers、Bryant H. Yang、Hou Chen、James L. Gleason
DOI:10.1021/ja00099a076
日期:1994.10
form tertiaryamides. In the presence of lithium chloride, the enolates of the corresponding pseudoephedrine amides undergo highly diastereoselective a1kylations with a wide range of alkyl halides to afford α-substituted products in high yields. These products can then be transformed in a single operation into highly enantiomerically enriched carboxylic acids, alcohols, and aldehydes. Lithium amidotrihydroborate
Pseudoephenamine: A Practical Chiral Auxiliary for Asymmetric Synthesis
作者:Marvin R. Morales、Kevin T. Mellem、Andrew G. Myers
DOI:10.1002/anie.201200370
日期:2012.5.7
Unrestricted: Pseudoephenamine is introduced as a versatile chiralauxiliary and an alternative to pseudoephedrine in asymmetricsynthesis. It is free from regulatory restrictions and leads to remarkable stereocontrol in alkylation reactions, especially in those that form quaternary carbon centers. Amides derived from pseudoephenamine exhibit a high propensity to be crystalline substances, and provide
Pseudoephedrine as a Practical Chiral Auxiliary for the Synthesis of Highly Enantiomerically Enriched Carboxylic Acids, Alcohols, Aldehydes, and Ketones
作者:Andrew G. Myers、Bryant H. Yang、Hou Chen、Lydia McKinstry、David J. Kopecky、James L. Gleason
DOI:10.1021/ja970402f
日期:1997.7.1
pseudoephedrine as a practical chiral auxiliary for asymmetricsynthesis is described in full. Both enantiomers of pseudoephedrine are inexpensive commodity chemicals and can be N-acylated in high yields to form tertiary amides. In the presence of lithium chloride, the enolates of the corresponding pseudoephedrine amides undergo highly diastereoselective alkylations with a wide range of alkyl halides to
A cleavable linker strategy for optimising enolate alkylation reactions of a polymer-supported Evans' oxazolidin-2-one
作者:Rachel Green、Andrew T. Merritt、Steven D. Bull
DOI:10.1039/b713966g
日期:——
A cleavable linker strategy has been used to optimise the enolate alkylation reactions of a recyclable L-tyrosine derived polymer-supported oxazolidin-2-one for the asymmetric synthesis of a series of chiral α-alkyl acids.
The absolute configurations of some aryl- and alkyl-substituted 3-phenylpropanoic acids
作者:M. B. Watson、G. W. Youngson
DOI:10.1039/j39680000258
日期:——
The configuration of (+)-2,3-diphenylpropanoic acid has been related to that of (R)-(–)-2-phenylpropanoic acid by converting both acids into (+)-1,2-diphenylpropane. The configuration of (+)-2-methyl-3-phenylpropanoic acid has been related to that of (R)-(+)-3-phenyl-2-(2-thienyl)propanoic acid by converting both acids into (+)-2-methyl-1-phenylhexane. (R)-(+)-3-Phenyl-2-(2-thienyl)propanoic acid has