RT info:eu-repo/semantics/article
T1 Chiral Squaramide‐Catalyzed Asymmetric Synthesis of N,O‐Acetals From Pyrazolinone Ketimines
A1 Gil Ordóñez, Marta
A1 Pérez Aragón, Miriam
A1 Martín Maroto, Laura
A1 Maestro Fernández, Alicia
A1 Andrés García, José María
K1 Síntesis asimétrica
K1 Organocatálisis
K1 Escuaramidas
K1 Pirazolinonas
K1 Cetiminas
K1 Acetales (N,O-acetales)
K1 Organocatálisis asimétrica
K1 Enantioselectividad
K1 N, O-aminales
K1 Cetiminas derivadas de la pirazolinona
K1 Centros de estereocentros cuaternarios
AB Quinine-derived bifunctional squaramide catalyzed the asymmetric addition of different alcohols to pyrazolone-derived Boc-ketimines, providing chiral pyrazolones containing a tetrasubstituted stereocenter bearing a new N,O-acetal motif. The products were isolated in satisfactory yields (up to 91%) and with moderate levels of enantioselectivity (up to 79:21 er) by using 5 mol% of the chiral squaramide catalyst across a broad substrate scope. Importantly, enantioenriched N,O-aminals can be efficiently recovered from the mother liquors by a simple recrystallization. The reaction was extended to other nucleophiles, thiophenol and N-methylaniline, providing the corresponding N,S- and N,N-acetals in moderate to good yield but low enantioselectivity.
PB Wiley
SN 0022-152X
YR 2025
FD 2025
LK https://uvadoc.uva.es/handle/10324/81354
UL https://uvadoc.uva.es/handle/10324/81354
LA spa
NO Journal of Heterocyclic Chemistry, 2026, vol. 63, n. 1, p. 49-59.
NO Producción Científica
DS UVaDOC
RD 05-feb-2026