244239-16-5Relevant articles and documents
Reaction of N-vinylic phosphazenes derived from β-amino acids with aldehydes. Azadiene-mediated synthesis of dihydropyridines, pyridines, and polycyclic nitrogen derivatives
Palacios, Francisco,Herran, Esther,Rubiales, Gloria
, p. 6239 - 6246 (2007/10/03)
Enamino phosphonium salts 2 are obtained by 1,2-addition of hydrogen chloride to N-vinylic phosphazenes 1 derived from triphenylphosphine. Aza- Wittig reaction of phosphazenes 1 derived from triphenylphosphine and 6 derived from diphenylmethylphosphine with aldehydes 3 leads to the formation of 2-azadienes 7. Reaction of azadienes 7 with enamines affords dihydropyridines 9 and 11, pyridines 12, and bicyclic nitrogen heterocycles 15-18 in a regioselective fashion, while heterodiene 20 reacts in the same way with pyrrolidinocyclohexanone giving 1-azaphenanthrene compound 21. Reaction of enamino phosphonium salts 2 with aldehydes 3 gives symmetrical dihydropyridines 5.