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 language | English |
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Pages (from-to) | 7925-7932 |
Number of pages | 8 |
Journal | Tetrahedron |
Volume | 58 |
Issue number | 39 |
Publication status | Published - 23 Sept 2002 |
Keywords
- reduction
- hygrazones
- hydrazines
- boron and compounds
- DIELS-ALDER REACTIONS
- CYCLIZATION
- KETONES
- REARRANGEMENT
- 1-AZADIENES
- REDUCTION
- REAGENTS
- ADDUCTS