Cycloaddition reaction of 2-azadienes derived from beta-amino acids with electron-rich and electron-deficient alkenes and carbonyl compounds. Synthesis of pyridine and 1,3-oxazine derivatives

J Org Chem. 2002 Apr 5;67(7):2131-5. doi: 10.1021/jo016273+.

Abstract

Functionalized keto-enamines 6 were obtained by nucleophilic addition of enol ethers to the imine moiety of 2-azadienes derived from dehydroaspartic esters 4. Reactions of 2-azadiene 4c containing three electron-withdrawing substituents (CO(2)R) with enol ethers 5 in the presence of lithium perchlorate led to the formation of tetrahydropyridine derivatives 7 in a regio- and stereoselective fashion. 2H-[1,3]-oxazines 10 and pyridine derivatives 12 and 13 were obtained by heterocycloaddition reactions of electron-poor azadienes 4d-g containing two electron-withdrawing substituents (4-O(2)N-C(6)H(4), CO(2)R) in positions 1 and 4 with carbonyl derivatives (ethyl glyoxalate 9a and diethyl ketomalonate 9b) and the electron-deficient olefin tetracyanoethylene 11.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / chemistry
  • Amino Acids / chemistry*
  • Aza Compounds / chemical synthesis*
  • Aza Compounds / chemistry*
  • Catalysis
  • Crystallography, X-Ray
  • Cyclization
  • Electrochemistry / methods
  • Ethers / chemistry
  • Ketones / chemistry
  • Lithium Compounds
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry
  • Molecular Structure
  • Oxazines / chemical synthesis
  • Oxazines / chemistry
  • Perchlorates
  • Pyridines / chemical synthesis
  • Pyridines / chemistry
  • Spectrophotometry, Infrared

Substances

  • Alkenes
  • Amino Acids
  • Aza Compounds
  • Ethers
  • Ketones
  • Lithium Compounds
  • Oxazines
  • Perchlorates
  • Pyridines
  • lithium perchlorate