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

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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

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Keywords

  • Amination
  • Chiral auxiliary
  • Reversal of stereoselectivity

ASJC Scopus subject areas

  • Biochemistry
  • Drug Discovery
  • Organic Chemistry

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