A suitable preparation of N-sulfonyl-1,2,3,4-tetrahydroisoquinolines and their ring homologs with a reusable Preyssler heteropolyacid as catalyst

G. ROMANELLI, D. RUIZ, E. GIACCIO, J. AUTINO

Molecular Diversity

Springer

Lugar: Amsterdam; Año: 2009 p. 1 - 5

1381-1991

We described the preparation of N-sulfonyl-1,2,3,4-tetrahydroisoquinolines, N-sulfonyl-2,3,4,5-tetrahydro-1H-2-benzazepines and N-sulfonyl-1,2,3,4,5,6-hexahydrobenzazocinewas catalyzed by a Preyssler heteropolyacid, H14[NaP5W30O110], (PA), supported on silica (PASiO240) with excellent yields by means of the Pictet–Spengler reaction of N-aralkylsulfonamides with s-trioxane. The reactions proceed with 0.5mol% of silica-supported catalyst in toluene at 70ºC. The catalyst can be recycled without appreciable loss of the catalytic activity.