Diastereoselective electrophilic α-amination of camphor N1-acyl N2-phenylpyrazolidinones: the metal enolate-dependent synthesis of two possible hydrazide diastereomers

Chin Sheng Chao, Chung Kai Cheng, Ssu Hsien Li, Kwunmin Chen

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Complementary approaches under enolate amination reactions for the synthesis of both α-hydrazidoacyl diastereomers have been achieved. Both isomers are obtained with high to excellent chemical yields and high stereoselectivities (up to >95:5 dr) when aryl-substituted camphor N1-acyl N2-phenylpyrazolidinone was treated with potassium hexamethyldisilylamide (KHMDS) and lithium hexamethyldisilylamide (LHMDS), respectively, followed by the addition of di-tert-butyl azodicarboxylate. The nondestructive removal of the chiral auxiliary, which can be carried out under mild condition, afforded the hydrazido alcohol with high enantiomeric ratio. The facial stereoselectivity and stereochemical course of the reactions are discussed.

Original languageEnglish
Pages (from-to)333-336
Number of pages4
JournalTetrahedron Letters
Volume50
Issue number3
DOIs
Publication statusPublished - 2009 Jan 21

Fingerprint

Camphor
Amination
Stereoselectivity
Lithium
Potassium
Metals
Alcohols
Isomers
di-tert-butyl azodicarboxylate

Keywords

  • Amination
  • Chiral auxiliary
  • Reversal of stereoselectivity

ASJC Scopus subject areas

  • Biochemistry
  • Drug Discovery
  • Organic Chemistry

Cite this

Diastereoselective electrophilic α-amination of camphor N1-acyl N2-phenylpyrazolidinones : the metal enolate-dependent synthesis of two possible hydrazide diastereomers. / Chao, Chin Sheng; Cheng, Chung Kai; Li, Ssu Hsien; Chen, Kwunmin.

In: Tetrahedron Letters, Vol. 50, No. 3, 21.01.2009, p. 333-336.

Research output: Contribution to journalArticle

@article{721507c5d28249b7b93ba19abfc88469,
title = "Diastereoselective electrophilic α-amination of camphor N1-acyl N2-phenylpyrazolidinones: the metal enolate-dependent synthesis of two possible hydrazide diastereomers",
abstract = "Complementary approaches under enolate amination reactions for the synthesis of both α-hydrazidoacyl diastereomers have been achieved. Both isomers are obtained with high to excellent chemical yields and high stereoselectivities (up to >95:5 dr) when aryl-substituted camphor N1-acyl N2-phenylpyrazolidinone was treated with potassium hexamethyldisilylamide (KHMDS) and lithium hexamethyldisilylamide (LHMDS), respectively, followed by the addition of di-tert-butyl azodicarboxylate. The nondestructive removal of the chiral auxiliary, which can be carried out under mild condition, afforded the hydrazido alcohol with high enantiomeric ratio. The facial stereoselectivity and stereochemical course of the reactions are discussed.",
keywords = "Amination, Chiral auxiliary, Reversal of stereoselectivity",
author = "Chao, {Chin Sheng} and Cheng, {Chung Kai} and Li, {Ssu Hsien} and Kwunmin Chen",
year = "2009",
month = "1",
day = "21",
doi = "10.1016/j.tetlet.2008.11.003",
language = "English",
volume = "50",
pages = "333--336",
journal = "Tetrahedron Letters",
issn = "0040-4039",
publisher = "Elsevier Limited",
number = "3",

}

TY - JOUR

T1 - Diastereoselective electrophilic α-amination of camphor N1-acyl N2-phenylpyrazolidinones

T2 - the metal enolate-dependent synthesis of two possible hydrazide diastereomers

AU - Chao, Chin Sheng

AU - Cheng, Chung Kai

AU - Li, Ssu Hsien

AU - Chen, Kwunmin

PY - 2009/1/21

Y1 - 2009/1/21

N2 - Complementary approaches under enolate amination reactions for the synthesis of both α-hydrazidoacyl diastereomers have been achieved. Both isomers are obtained with high to excellent chemical yields and high stereoselectivities (up to >95:5 dr) when aryl-substituted camphor N1-acyl N2-phenylpyrazolidinone was treated with potassium hexamethyldisilylamide (KHMDS) and lithium hexamethyldisilylamide (LHMDS), respectively, followed by the addition of di-tert-butyl azodicarboxylate. The nondestructive removal of the chiral auxiliary, which can be carried out under mild condition, afforded the hydrazido alcohol with high enantiomeric ratio. The facial stereoselectivity and stereochemical course of the reactions are discussed.

AB - Complementary approaches under enolate amination reactions for the synthesis of both α-hydrazidoacyl diastereomers have been achieved. Both isomers are obtained with high to excellent chemical yields and high stereoselectivities (up to >95:5 dr) when aryl-substituted camphor N1-acyl N2-phenylpyrazolidinone was treated with potassium hexamethyldisilylamide (KHMDS) and lithium hexamethyldisilylamide (LHMDS), respectively, followed by the addition of di-tert-butyl azodicarboxylate. The nondestructive removal of the chiral auxiliary, which can be carried out under mild condition, afforded the hydrazido alcohol with high enantiomeric ratio. The facial stereoselectivity and stereochemical course of the reactions are discussed.

KW - Amination

KW - Chiral auxiliary

KW - Reversal of stereoselectivity

UR - http://www.scopus.com/inward/record.url?scp=57149132089&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=57149132089&partnerID=8YFLogxK

U2 - 10.1016/j.tetlet.2008.11.003

DO - 10.1016/j.tetlet.2008.11.003

M3 - Article

AN - SCOPUS:57149132089

VL - 50

SP - 333

EP - 336

JO - Tetrahedron Letters

JF - Tetrahedron Letters

SN - 0040-4039

IS - 3

ER -