One-Pot Synthesis of Multifunctionalized 1-Pyrrolines from 2-Alkyl-2<i>H</i>-azirines and Diazocarbonyl Compounds
Ilya P. Filippov, Михаил С. Новиков, Alexander F. Khlebnikov, Николай В. Ростовский
Abstract
-azirines with diazocarbonyl compounds has been developed. This one-pot approach includes the Rh(II)-catalyzed formation of 4-alkyl-2-azabuta-1,3-dienes, followed by the DBU-promoted cyclization, and features a good substrate tolerance. The 1-pyrrolines containing an ester group at the C3 were prepared in a three-step one-pot procedure starting from 5-alkoxyisoxazoles. The cyclization of 2-azabutadienes to 1-pyrrolines most likely proceeds via the 6π electrocyclization of a conjugated NH-azomethine ylide.
Topics & Concepts
AlkylAnnulationChemistryConjugated systemYlideSubstrate (aquarium)Combinatorial chemistryCatalysisOrganic chemistryMedicinal chemistryBiologyPolymerEcologyCyclopropane Reaction MechanismsCatalytic C–H Functionalization MethodsSynthesis and Catalytic Reactions