Synthetic and mechanistic studies of the aza-retro-Claisen rearrangement. A facile route to medium ring nitrogen heterocycles.
An efficient synthesis of medium-sized heterocyclic rings was achieved using a one-pot aza-Wittig/retro-aza-Claisen sequence of vinyl cyclobutanecarboxaldehydes derived from simple allylic carbonates. The use of various Staudinger reagents in the aza-Wittig reaction allows for a variety of N-substituted products to be obtained. The rearrangement is under thermodynamic control driven by relief of the cyclobutane ring strain and resonance stabilization of the resulting vinylogous amide/sulfonamide.
Boeckman
Robert K
RK
Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, USA. rkb@rkbmac.chem.rochester.edu
Genung
Nathan E
NE
Chen
Ke
K
Ryder
Todd R
TR
D001372:Aza Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism; D013816:Thermodynamics
D001372:Aza Compounds; D006571:Heterocyclic Compounds