Straightforward approach to iminoxazines and azetidinimines via 1,4-additions of chelated enolates toward nitroalkenes.
[reaction: see text] Chelated amino acid ester enolates undergo 1,4-addition toward nitroalkenes in a highly stereoselective fashion. Trapping the nitronates formed in the addition step with chloroformates or acyl chlorides gives rise to highly reactive intermediates that directly undergo cyclization. Depending on the N-protecting group (PG) used, iminoxazines or azetidinimines are formed in a simple one-pot protocol.
Mendler
Barbara
B
Universität des Saarlandes, Institut für Organische Chemie, Im Stadtwald, Geb. 23.2, D-66123 Saarbrücken, Germany.
Kazmaier
Uli
U
Huch
Volker
V
Veith
Michael
M
D000475:Alkenes / Q000138:chemical synthesis*; D000596:Amino Acids / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry; D007097:Imines / Q000737:chemistry*; D015394:Molecular Structure; D009574:Nitro Compounds / Q000138:chemical synthesis*; D010078:Oxazines / Q000737:chemistry*; D013237:Stereoisomerism
D000475:Alkenes; D000596:Amino Acids; D006843:Hydrocarbons, Chlorinated; D007097:Imines; D009574:Nitro Compounds; D010078:Oxazines