1,2-reduction of alpha,beta-unsaturated hydrazones using dimethylamine-borane/p-toluenesulfonic acid: an easy route to allyl hydrazines

M E Casarini, F Ghelfi, E Libertini, U M Pagnoni, A F Parsons

Research output: Contribution to journalArticlepeer-review

Abstract

alpha,beta-Unsaturated hydrazones can be easily converted into N-allyl hydrazines by reaction with dimethylamine-borane/p-toluenesulfonic acid under mild reaction conditions. The reduction works well for N'-allyhydrazides but N'-allyl-N,N-dimethylhydrazines are rapidly reoxidised by air and so need to be manipulated under an inert atmosphere prior to M-acylation. Competitive conjugate reduction can also be observed and the regioselectivity of the dimethylamine-borane attack is determined by steric and/or electronic factors. The procedure is also effective for the C=N reduction of unconjugated hydrazones. (C) 2002 Elsevier Science Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)7925-7932
Number of pages8
JournalTetrahedron
Volume58
Issue number39
Publication statusPublished - 23 Sept 2002

Keywords

  • reduction
  • hygrazones
  • hydrazines
  • boron and compounds
  • DIELS-ALDER REACTIONS
  • CYCLIZATION
  • KETONES
  • REARRANGEMENT
  • 1-AZADIENES
  • REDUCTION
  • REAGENTS
  • ADDUCTS

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