Abstract
A two-step, practical, regiospecific, and readily scalable benzannulation protocol for the preparation of novel 3-alkyl- and 3-aryl-substituted 2-nitronaphthalenes is disclosed. Addition of a β-nitrostyrene or nitroalkene to a solution of freshly prepared lithiated o-tolualdehyde tert-butyl imine first leads to the formation of a nitronate, via rapid 1,4-addition, then an intramolecular aza-Henry reaction takes place to afford a six-membered carbocycle. Subsequent treatment of the reaction mixture with aqueous acid affords novel substituted cyclic nitrostyrenes that can be conveniently aromatized via a one-pot radical-induced bromination and elimination sequence to furnish the corresponding 3-alkyl- or 3-aryl-2-nitronaphthalenes in excellent yields. The straightforward syntheses of 2-aminonaphthalenes, substituted BINAMs, 2-naphthols as well as tricyclic fused 1,2,3-triazoles are also described.
Original language | English (US) |
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Article number | SS-2013-C0260-FA |
Pages (from-to) | 1719-1729 |
Number of pages | 11 |
Journal | Synthesis (Germany) |
Volume | 45 |
Issue number | 13 |
DOIs | |
State | Published - 2013 |
Keywords
- 2-aminonaphthalene
- 2-nitronaphthalene
- BINAM
- cyclic nitrostyrene
- fused triazole
ASJC Scopus subject areas
- Catalysis
- Organic Chemistry