Abstract
This review describes the free radical cyclisation of enamides using tributyltin hydride, manganese(III) acetate, copper(I) complexes or dichlorotris(triphenylphosphine)ruthenium(II). These cyclisations can proceed via either 4-exo or 5-endo pathways, to produce (beta- or gamma -lactam products. respectively. In general. the reactions produce gamma -lactams derived from an unusual (disfavoured) 5-endo-trig radical cyclisation. These results can be explained on the basis of a reversible cyclisation mechanism; the 4-exo cyclisation produces the kinetically favoured B-lactam while the 5-endo cyclisation produces the thermodynamically more stable gamma -lactam. (C) 2001 Academie des sciences / Editions scientifiques et medicales Elsevier SAS.
| Original language | English |
|---|---|
| Pages (from-to) | 391-400 |
| Number of pages | 10 |
| Journal | COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE II FASCICULE C-CHIMIE |
| Volume | 4 |
| Issue number | 6 |
| Publication status | Published - Jun 2001 |
Keywords
- cyclisation
- lactams
- radicals and radical reactions
- N-HETEROCYCLE SYNTHESIS
- ALPHA-HALO AMIDES
- SUBSTITUTED PYRROLIDINONES
- SECONDARY AMIDES
- BETA-LACTAMS
- CYCLIZATION REACTIONS
- ACID-ANALOGS
- PYROGLUTAMATES
- 5-ENDO-TRIG
- 4-EXO-TRIG